I would be interested to know how only children fall into this analysis. If the oldest child has more intellectual curiosity because they received more attention, you'd expect only children to have received even more attention still.
The average of the population? (In this case, the average SSC reader.)
If you have a big enough sample, you can ask if the average only child scores higher "Openness" than the average reader, or if their self-reported IQ is higher. That's a meaningful comparison I believe.
It's pretty likely that first born children were more likely to respond to the survey given that Scott openly stated he expected more first born children to be among his readership, giving people an impression that first born is better and they might feel good about themselves vs second born children who might feel bad about themselves.
7. I plan to confirm or disprove, once and for all,
whether our community has more older siblings. For lack
of a fancier way to do this, I’ll take the set of all
people who have exactly one sibling, and see what
percent of them are older vs. younger. If it’s
significantly above 50% older, I’m going to interpret
this as a birth order effect. I’ll do the same with the
set of people who have two siblings, three siblings,
etc, and combine them all for a final determination.
Half-siblings will be ignored. If you have any problems
with this methodology, tell me now.
The prevalence of older siblings could be because of other reasons perhaps? Only people born with a certain period of time are likely to be interested in transhumanism and of those more are older siblings than otherwise.
He explained that, too. The average age of all the older siblings that responded and the the average age of all the younger siblings that responded were within 1 year.
I'd have preferred if Scott posted an encrypted timestamped message on Pastebin before the survey (to register his intended experiments), and released the keys after the survey; "this could skew your results please don't read" is not particularly well controlled.
I find it highly unlikely that this could produce an effect this big. If anything I would expect the effect to be in the opposite direction motivated by defiance. (though then I am a second born who did respond to the survey (without giving any thought to my birth order))
You could equally propose that non-first-born children are more likely to respond to overthrow Scott's hypothesis (since he's pretty open to and reasonable about counterarguments)
Sure they exist, but we don't want to talk about it. There is a strong motivation to be able to say that everyone is created equal, regardless of how uncontrollable factors affect you (birth order, height, race, gender). We don't want to kill someone's motivation to study for college just because they are a third child. But stereotypes exist for a reason. The hard part is separating hatred-based stereotypes from the stereotypes based on observations throughout history.
Regarding birth order, the "middle child" stereotype is prevalent in Western society. Did the middle child stereotype spring from some sort of effort by first-borns to keep their lower-ranked siblings in line (a la racism?)? I doubt it. The middle child stereotype probably came from hundreds of years of observations. It's a similar story for the first-born and last-born stereotypes- they weren't created out of any prejudice, but probably from hundreds of years of mothers chatting about their kids.
Like the article says, denying that the differences exist prevents us from ever finding out why (because people won't do research on something that doesn't exist). So let's acknowledge that some groups of people are different than other groups, and then respectfully do research to figure out why. The differences could be societal- perhaps first-borns are treated with more care by their parents, or they could be biological- perhaps the hormonal changes in a pregnant woman are different for each successive child, or they could be something else entirely- I had many of the same teachers as my older sister, and I often benefited from them having a pleasant experience with her, making my time in class much easier.
But anyway, the first step is acknowleding that a difference exists, and that you aren't somehow "birth order-ist" just because you acknowledge that first-born kids often outscore lower order kids on many metrics.
The middle child stereotype is that middle children receive less attention than both their older and younger siblings, resulting in them underperforming in several metrics. In three child families, the "best" child is first-born, the middle child gets ignored, and the third-born gets pampered.
Obviously this doesn't hold true for every family, and I'll acknowledge that this stereotype is may be less prevalent in cultures that tend towards small families (one or two kids).
Funnily enough in our family the youngest child is the best performing (so far, he’s still a teenager) follow d by the middle sibling, and then the eldest sibling is dead last in terms of performance in life in general.
My experience as the youngest child is that neither of my parents wanted to repeat the "mistake" they made giving my brother resources and supporting him. So where my brother generally got things like cars and a college education, I got things like jobs and student loans.
It's not actually a hot-button issue, at least not on the level of gender and race stereotyping. Claiming a difference based on birth order is more likely to elicit a "you're behind the times" type of response rather than a "you're a horrible person" type of response if you claimed a gender or race based difference.
I don't think it should be ignored just because there are more hot-button issues that can be fixed- recruiting women and racial minorities into STEM is probably a better bang for your buck than trying to level out a 1 point difference in IQ based on birth order (how would that even happen?). Even though birth order has a low effect size, it would be nice to know why it happens and how much we could do to change it.
> But anyway, the first step is acknowledging that a difference exists
And then immediately the second step is acknowledging that these differences are, in most cases, too small to matter, as even Scott Alexander points out when he refers to the existing academic research.
There are few studies of birth order effects just like there are few studies of the effect of birthmarks on human psychology. There's mostly just not enough there for it to be an interesting investigative avenue.
Previous researchers said "too small to matter," Scott's sentiments were more along the line of "small, but might matter in some areas." His sentence directly after him acknowledging the small effects: "I agree they may only exist for a few traits, but they can be strong enough to skew ratios in some heavily-selected communities like this one."
And the whole "few studies exist because it isn't interesting" is the cycle that he's pushing to break out of. Enumerating the differences could make them interesting to psychologists, because then they might be able to determine a cause and intervene. The second to last paragraph of his post explains it more.
Matter for what, exactly? Case in point, there's a distinct physiological difference between me, a guy who has lived at almost sea-level altitude for his entire life (I'm in my late-30s now) and a guy who has lived in La Paz, Bolivia, at 3,000 m altitude: I won't be as able to physically perform at that altitude as he is, and that matters (for example if I were a professional footballer and I wanted to win a match against the Bolivian's guy team most probably I would lose, even if I were Messi, one of the best footballers ever). And I could add countless other differences between different groups of people from all over the world from the sports' world alone. That wouldn't make me a racist because I don't believe in races, but I believe (based on my past observations) that there are indeed differences between the 7 billion humans inhabiting this planet.
In your example, the difference between the high altitude person and you would be too small to matter if you weren't a mountain climbers or professional athlete. So for most people altitude differences are to small to matter but they do matter to certain subgroups.
The analog here from Scott's article is that he mentions that this skew towards first-borns might be STEM specific. A 1.5 point difference in knowledge based (creative) careers might matter. But most people work in training based (vocational) careers, and a 1.5 point difference might not matter there.
> the difference between the high altitude person and you would be too small to matter if you weren't a mountain climbers or professional athlete.
I just said that it matters for sea-level people who have to perform physical tasks in La Paz, a populous city, nonetheless. I gave Messi's example because that was the easiest one, but I could have given an example of a Bolivian guy moving to La Paz from the country's planes area and trying to find a job physically carrying stuff in a warehouse. His rate of work would be much diminished compared to a guy born and raised in La Paz, so, presumably, his pay would also be lower. It matters because it shows that our bodies have changed and are indeed different based on certain geographical circumstances, but because some crazy guys in the late 19th-early 20th century have decided to kill millions of people based on some other differences that means that it has become tabu to discuss about this.
Small relative to other sources of variation. For example, a professional footballer who is used to sea-level will still perform better at a match in La Paz than an average joe who was born in La Paz. Similarly, Similarly, there might be minute differences between people based on birth order, but in most scenarios these would be swamped by all other factors that go to make up someone's personality.
That doesn't make me politically correct, rather it makes me unmotivated to further explore the topic.
I think the "middle child" (second oldest) comes form the fact that he should be ready to take over the duties of the oldest if he dies but must not grow to be "better" then the oldest.
Can't leave to make it on his own like the younger siblings but by default don't inherit the family fortunes/business/whatever.
But as in the west we don't live in a society where the oldest inherits his fathers job/title(s) this doesn't really apply anymore.
> the first step is acknowleding that a difference exists
No, the first step is acquiring sufficient high-quality data and reproducing findings.
> we don't want to talk about it.
No, some want to talk about it prematurely because it speculatively supports conclusions that fit their agenda.
> that you aren't somehow "birth order-ist" just because you acknowledge that first-born kids often outscore lower order kids on many metrics.
And yet here we are, hijacking an interesting if incomplete study for your own purpose and hiding behind "but science" whilst having an incomplete understanding of it.
Do you realize that your counterargument can be used pretty much as-is to deny climate change? If your argument is so abstract that it can be applied on anything, perhaps it's not a very usefule argument.
> the first step is acquiring sufficient high-quality data and reproducing findings
I agree that good data is a pre-requisite. An online survey of blog readers isn't going to upend psychology as we know it, but Scott's findings of a heavily skewed numbers of first-borns in the survey probably can't be explained as just "online survey crap." The only "online crap" explanation I can think of is if the "first born" box was pre-filled and people changed the response for their number of siblings but didn't change the pre-filled response for birth order. This unbalanced first-born ratio is something that could be looked at in a bigger and more rigorous survey.
> some want to talk about it prematurely because it speculatively supports conclusions that fit their agenda
We have to talk about it otherwise we'll never get any data- I'm not advocating policy decisions based on incomplete research, I'm advocating discussion and follow on research. You can't do research without discussing ideas ahead of time.
> yet here we are, hijacking an interesting if incomplete study for your own purpose
I didn't hijack anything. I was making a comment that stayed on topic and is related to the post.
BTW, I'm a statistician, and have a pretty good understanding behind the science of surveys. I'm admittedly not an expert in psychology. From the HN guidelines: "Please respond to the strongest plausible interpretation of what someone says, not a weaker one that's easier to criticize. Assume good faith."
> The only "online crap" explanation I can think of is if the "first born" box was pre-filled and people changed the response for their number of siblings but didn't change the pre-filled response for birth order.
In the survey, birth order is inferred from the field that records the number of elder siblings. If the form design nudged respondants to not completing that field more than other fields (via unclear or biasing wording, ordering effects, etc) that could produce a similar outcome.
I haven't looked at the survey so no idea, but there are more potential causes than defaults.
I took the survey, am a younger sibling, and have very strong memory of the questions being very fair. If I think I my hardest I can't imagine any reason another responder would have been pulled to unconsciously report wrong data on the birth order questions.
With respect, your opinion is anecdotal. These things aren't always obvious, or even visible to respondants at all.
I'm not saying there's no effect, just that right now this claimed finding seems contrary to the existing body of evidence.
This finding may well be accurate (and the existing studies in error). Alternatively it may be a mistake. Alternatively both could be true and this survey represents a special case, some kind of selection bias.
Given that this survey is yet to be peer reviewed or replicated I think the most likely explanation is a mistake, but that's just my perception of the balance of probabilities.
> "Sure they exist, but we don't want to talk about it...the first step is acknowledging that a difference exists"
Reminds me of the suppressed discussion about males having a slight preference towards things while females having a slight preference towards people which caused so much of a stir at Google.
> There is a strong motivation to be able to say that everyone is created equal, regardless of how uncontrollable factors affect you...
This, this, this, this, this!
People are not created equal at all! That should be obvious to anyone evaluates the world in even a cursory manner. There are material, physical, emotional and intellectual differences between any two individuals.
I have a (totally baseless and unvalidated) theory: If you accept that all people are not equal you are presented with a curious metaphysical problem when considered from a Western "Christian" perspective; why did God create both paupers and princes?--i.e., why are some born into ridiculous wealth and others crippling poverty? Eastern traditions handle this typically by some appeal to "reincarnation" and/or "karma." You can't do this in the Western view because everyone there is living to get into heaven, not escape samsara (it's funny that in some views these are actually the same thing :)
In earlier times when I debated fundamentalists, the retort would be "each is tested in his own way" or something along those lines. How entirely unsatisfying, the game is rigged and we're all not starting from the same position! For the modern, non-secular mind, it seems people would rather maintain the fiction of equality than consider the fact that the world is a profoundly un-equal place.
Yeah, the world is incredibly unequal. I do think it's generally not explained well (or even understood well), and for most, they either ignore it, or acknowledge it and consciously set it to one side until it clicks.
I'll bite though on the religious bit (I'm a practicing Christian). I think people give unsatisfying answers because a base assumption is that God can do anything. But really, there are things God cannot do, or he would cease to be God...
Add in Christ's atonement making up for all injustices and pains, the ability to choose as paramount our being, and our existence extending beyond both ends of this mortal existence. And then I think we have most of the pieces necessary to construct an answer that's not entirely dissatisfying.
I'm not here to discuss it per-say, just wanted to say that I think most (religious) people build their arguments from some unchecked assumptions that lead to unsatisfactory results.
(As a mostly irrelevant aside - if you've ever read the second MistBorn series, I think the God-like figure in that series touches well on interventions of God)
> If you accept that all people are not equal you are presented with a curious metaphysical problem when considered from a Western "Christian" perspective; why did God create both paupers and princes?--i.e., why are some born into ridiculous wealth and others crippling poverty?
When I was still a catholic I "solved" this by assuming God put souls with more capability to survive hardships in bodies that experience more hardships. Basically the world is a level-scaling MMORPG :)
When I stopped being a catholic I just assumed there's nothing fair about universe, it's just random, so there's nothing to explain.
The fact we don't have equal chances is obvious, even people saying otherways usually know this deep down, they just won't admit it because ideology, so they might say "people are equal, but society is keeping some of us down" (clearly not the only factor - see psychological development problems), or "people are equally talented at different things, some of us don't get to realize these talents" - which might be true, for general enough definition of talent, but is quite unlikely (if nobody's supervising the distribution of talents - how do you ensure everybody's got the same amount?). And even if it's true - the definition has to be so general that in practice it doesn't matter.
> When I was still a catholic I "solved" this by assuming God put souls with more capability to survive hardships in bodies that experience more hardships. Basically the world is a level-scaling MMORPG :)
Interestingly, if you an understand the synthesis of eastern metaphysical concepts such as "maya" (illusion), "karma" (causation) and their logical implications such as reincarnation, you arrive at a similar conclusion -- the world is essentially a game (meant to be enjoyed, a journey, a sport to be reveled in), which scales your instance based on your karma! There's respawning too :)
Choose your own adventure!
Just thought I'd drop a book recommendation here: "The Monk and the Philosopher" - Jean-François Revel and Matthieu Ricard [0]. A much younger, atheist, science-absolutionist (?-haha) me had his mind blown by this text. It made me seriously question my world view (which would be later be shattered by a friend with considerable philosophical talent). I do not currently identify as a Buddhist, and I'm not sure how it would be received now, but it certainly was useful in breaking a certain science-dogma in me.
But aren't "created equal", and "set up with equal conditions" two entirely different discussions? While I'd personally assume "birth order effects" if a thing would be almost entirely nurtured based, that's not what OP was saying, at least not entirely.
> The differences could be societal- perhaps first-borns are treated with more care by their parents, or they could be biological- perhaps the hormonal changes in a pregnant woman are different for each successive child, or they could be something else entirely
No one brought it up directly, but I can't help but think that some of this thread has undertones of the Damore discussion, which drives the argument from:
Societal changes we could make - to - these things (sorta kinda maybe based on pseudoscience) might not be societal and shouldn't be addressed (or at least not in the way they currently are).
I tend to be strongly in the former camp, which it sounds like you could be too. But let's not conflate those two separate conversations.
Race and gender has a profound effect on your prospects, but not in a way we can't fix.
That God created people with different prospects -- "paupers and princes" -- is explicit in the bible. The ninth chapter of Romans is quite clear about it. Jacob and Esau were twins, but God loved one and hated the other. Their destinies were set before their birth. The conclusion of the matter is that it is not of him who runs, nor of him who wills, but of God who shows mercy.
Romans 9 is rather controversial in Christianity these days. A lot of people will tell you it doesn't mean what it seems to be saying. But if you take it on face value, it explicitly acknowledges that the game is rigged. God makes different people to serve his different purposes, and that is the way it is meant to be.
When you say 'purpose'; what do you mean? I have trouble conceiving an all-powerful entity having purpose at any level of the universe because it's meaningless to have purpose when you're all-powerful.
Some clarity around "God's purpose" would be helpful.
To be all-powerful means you have the ability to effect any and all ends that you desire. It means you can realize all your purposes. If one doesn't have any desires (i.e., purposes), I'm not sure it would mean anything to say one is all-powerful.
"If you accept that all people are not equal you are presented with a curious metaphysical problem..."
If you accept that all people are not equal, then you are presented with a number of curious metaphysical problems. The big one is, how do you limit the damage caused by the lessers?
>I had many of the same teachers as my older sister, and I often benefited from them having a pleasant experience with her, making my time in class much easier.
For my brother and me it was the same, except he was really narrowly interested. He left a very bad impression with every sports and arts teacher I had. And with sports and arts there's no hard proof that you're better than the prejudice.
What do we actually know about the history of the "birth order" stereotype? It's possible that birth order is an old tradition, or maybe it was introduced in modern times, e.g., in some magazine article.
During the hundreds of years of observations, what were social conditions like? What social classes were studied? How did the high rate of infant and maternal mortality affect those conditions? The main change in successive children was that some of them died.
"But anyway, the first step is acknowleding that a difference exists, and that you aren't somehow "birth order-ist" just because you acknowledge that first-born kids often outscore lower order kids on many metrics."
The second-to-last step is deciding what you want to do with this information.
> But stereotypes exist for a reason. The hard part is separating hatred-based stereotypes from the stereotypes based on observations throughout history.
The problem with stereotypes isn't just when they are "hateful" or "inaccurate"; the problem with stereotypes is also when they are used to deny individual variation.
This article is going to be flagged into oblivion into a few hours. We're not discussing the relationship between biological and psychological traits on HN.
Alternative explanation: this article is just not good science. It:
* doesn't control whether the not-first-borns are outside the target demographic (too old or too young)
* doesn't look at children without siblings
* more importantly: is just a cross section, so no causal relationships can be gleaned from that
* also highly problematic: is self-selecting, with no discussion of the distribution of people not participating. With a poll question like that that alone invalidates every result, as obviously it invites bias towards readers who deem themselves smarter than their
siblings
* is not discussing, and controlling for, alternative explanations for the observed result
All in all the margin of error is almost certainly a multiple of the effect size, thus rendering the results useless. Which they are anyway, because you can only answer a question like the one given in the article with longitudinal studies.
This doesn't seem like a valid approach to me. To take a specific group, measure something, and assume that metric had an impact on them being in that group.
It did. The data set is biased towards being older sibling about 3:1. If the statistical distribution is fully shown then it could be some sort of an argument.
What do you mean by "reproduced on general population"? This is explicitly a study of SSC readers. Obviously in general population you won't find that oldest siblings outnumber younger siblings by 3:1.
A trans-humanist group might be more likely to have access to a time machine than most other groups, but I still don't think it is very likely that joining the group caused them to become a first-born child. It is much more likely that if there is a causal relationship, being a first-born child caused them to be more likely to join the group.
It's odd to discuss this without also mentioning the very strong apparent affects of birth order on sporting ability, eg [1].
I'd never heard of the supposed higher intelligence of first born, but I've heard a lot about the sporting side and anecdotally I've noticed it too (I am the oldest sibling in my family).
I agree with this, but the reason I'm focusing on intellectual curiosity was that of all the traits measured in the survey, it was the one that did show a significant effect of firstbornness, and it was also the only personality trait with a significant effect of firstbornness in Rohrer's study.
I'm not just assuming it, I'm saying that two analyses showed it was the only trait that mattered, and then it suffices to explain the current data.
Wierd, I'm the youngest of 6, and I'm acknowledged by the others as the smartest of the lot, by quite a margin. "bloody little genius" has been my nickname since I'm about 8 ;-)
What's weird about that? On average men outrank woman in professional tennis, that doesn't make it weird that Serena Williams would utterly destroy me and most men on the courts 10 out 10 times.
Single points aren't anti-points to statistical effects. Now if you happened to have a thousand friends that where also the youngest of 6 and happened to test higher on IQ scores, that would be weird. For more than one reason.
Well it IS wierd, because you would assume than that 'eldest child' principle would get at least linearly worse the more kids there are in a family... So I must be particularly lucky, OR perhaps we don't really have good numbers for the other end of the spectrum, regarding 'youngest child' general performances?
Or, again, perhaps there is a large part of cultural bias ("eldest/heir" of the family being assumed as better) so given more attention/resources... And that since I'm from a family with a single mother (who didn't have time/inclination for that) I was spared that?
In any case, I think making up "exists and are strong" conclusions without taking into account more parameters is simplistic at best...
It is possible that like many other effects, firstborn effects are subject to law of big numbers. (Or some statistical distribution other than Gaussian.)
Alternatively birth distance (time between births) or age of mother are the actual correlate. We do not know.
> Well it IS wierd, because you would assume than that 'eldest child' principle would get at least linearly worse the more kids there are in a family
First. The word is weird.
Second. No, you would not assume that. Why would you assume that? You could also with equal validity assume that something is present in the mother with the first-born that is absent in all the rest. You could also assume the study is hokum and missed something obvious.
Third. This “Single points aren't anti-points to statistical effects.” is _exactly_ why it isn't weird. Even supposing there is some statistically distributed effect you as a single point is a total non-issue. You are not special. Do get back to me if you've three heads or something.
Fourth. To think it is weird suggests you are in fact not as smart as you think you are. :)
Fifth. To continue arguing the point when it has been explained to you why you are wrong is again indicative of not being as smart as you think you are. :) :)
First. I love people who seems to associate spelling with intelligence and take high pride it pointing out other people mistakes, without any knowledge of how many languages they might be fluent in.
Second. Oops, no seconds here, First is usually enough for me to lose interest in said people.
To me it seems most likely that it is entirely due to environmental/nurturing reasons rather than some innate effect of being first out of their mother. For example money for school can vary, and the parents attitude towards nurturing thier children definitely does.
There's a handful of comments kind of getting tripped up here. Scott is relying on a 1-2 punch-- First, that openness to experience was decently different in the two groups (73rd percentile vs 69 percentile) and then that most Big5 tests aren't done well. (
Big5 is a valid personality test-- it gets decent test/re-test scores, but it's still weak. Myers-Briggs fails because, despite being very similar to the Big5, it doesn't have good enough test/re-test scores.)
Scott cites another study that says when you test openness properly, you get a wider distribution. So if you pair those two together, you get a decent sized effect. Maybe.
This doesn't seem to be a "birth order" effect, so much as a "first born" effect. Once you get past the first child, there doesn't seem to be much influence. That makes me very skeptical of any biological explanation, as you would expect to see more of a tail-off.
I think it's more likely a measurement error, or some subtle statistical effect caused by a combination of probability skewing and demographic changes.
> I think it's more likely a measurement error, or some subtle statistical effect caused by a combination of probability skewing and demographic changes.
A possible statistical contribution I can think of is the skewness of the age distribution within the population of readers. Here is the distribution charted:
Consider just the bins 20 (ages 10-20), 30 (ages 20-30) and 40 (ages 30-40). We can see that, of the three groups, teens are by far the least likely of these groups to read the blog, and people in their 20s are the most likely.
Now consider two groups of two-sibling families that lie within this range, where one sibling is in one bin, and the other the next. E.g. the first group where one is a teenager, the first-born is in their twenties, and the second where one is in their 20s, and the first-born is their 30s.
Case 1: If you take a random family from the [teen, 20s] group, how likely is it that the reader from this family is younger or first-born sibling? Since those in their 20s are much more likely to read the blog, it is much more likely that the reader is in their 20s, and is the first-born.
Case 2: Now take a random family from the [20s, 30s] group. How likely is it that the reader is the younger sibling or the first-born? In this case, because readers in their 20s are more common than readers in their 30s, it is more likely that the reader is the younger sibling.
However, the ratio of readers in their 30s to readers in their 20s is much closer than that between the 20s and teens. This makes it more likely in that in case 2 that the reader is still the first-born. Therefore, if the number of families in each group is equal, we would expect to see, in aggregate, more first-born readers than younger siblings.
I'm not saying that this is happening in the actual data, you'd need to do more analysis, and probably need more data about the ages of siblings, or that it is a significant enough effect to cause the result found. But it demonstrates that statistical analysis can involve subtle effects that are not obvious without careful consideration. As such, we should be very wary of making any conclusions about causes, either birth order or anything else.
But by that logic younger siblings would be overrepresented next bin, [30,40]. What goes up must come down.
Personally, I mulled over it for a while and I don't see any mere "statistical" effect that's plausible. I think we are forced to conclude there's a psychological difference with firstborns.
Or is it a physiological change that occurs in the mother after giving birth; one that doesn't change much further on subsequent births? Death rates due to complications after childbirth were quite high during 99.999% of our history. It's not out of the question for there to be an evolutionary adaptation that puts a little extra oomph into the firstborn in case the mother dies before having a chance for a second, even if it caused a higher risk of death (due to giving the embryo more of the mother's resources in vitro) to do so.
I have 2 boys, both adopted, and both biologically the youngest.
Yet, "oldest children are more conservative, youngest children are more creative, etc." and the oldest being more intellectually curious describes them perfectly.
So, anecdotally, my study of 1 data point says it's probably nuture and not nature.
There is also a disproportionate amount of people online that are born jan 01 1900, and have mothers with the maiden name "asdf". Several thousand % more than you would expect.
As explained in other comments[1], being the eldest sibling wasn't the default answer to a question.
Instead, people were asked to enter into a text field their number of older brothers, older sisters, younger brothers, younger sisters.
Not an issue with this study, but possibly worth noting that, naturally, there must be more firstborns than subsequent-borns (not counting the generic middle-child grouping). This could lead to a larger preceived effect.
Actually, it would be impossible for there to be more firstborns than subsequent-borns (barring death) because siblings require 2+ people, of which one and only one will be firstborn.
For every second born, there must be a first born, but not vice versa. For every third born, there must be a second born and a first born, but not vice versa...
So you're more likely to encounter a first born in the real world than any nth born, since some families will have only had one child.
The survey asked for numbers of older brothers, younger brothers, older sisters, and younger sisters. The main analysis on the post is for people with one sibling, and there are exactly as many people with one sibling whose sibling is older as there are whose is younger.
Could be one factor. I read a thing the other day that said something about child birth triggering some sort of immune reaction in the mother's body. That could mean that the second child is born under slightly less ideal conditions or something like that.
> But these demand strong effects of parenting on children’s later life outcomes, of exactly the sort that behavioral genetic studies consistently find not to exist
Would like to hear more details to that claim. When ever I read about genetic factors (For example on the topic of depression), I keep hearing that without the environmental factors the genetic indicators loose their predictive power. Genetic factors in behavioral science make a person more effected by environmental factors, but alone the genetic factor tend to have no effect.
To take the explicit example in the article. Is there an measurable effect in adult life that correlate to the amount parents focus and dedicate time to them as child? In rats I have heard enough studies to show a very strong correlation between stress in adult life and time that the rat got groomed as young by the mother. Could it be so simple that parents spend a bit more time/focus with the first child during the first few years, while the second child receive a bit less since there is now two children and the parents are a bit more experienced and feel more secure in parenting. While rats and humans are not identical, it is a strong hint that "parenting style" might carry an effect into adult life.
Although heritability estimates are significantly greater than 0%, they are also significantly less than 100%. As noted earlier, heritability estimates are substantial between 30% and 50%.... No traits are 100% heritable (e.g., Plomin, 1989; Turkheimer, 2000).
Check out [1] - Top 10 Replicated Findings From
Behavioral Genetics
In particular, "all psychological traits show significant and substantial genetic influence" mostly contradicts your comment, also "the heritability of intelligence increases throughout development" - i.e. environmental factors (parenting) matter when kids is young, but less so when they turn into adults.
Finally, we note that 4 of the top 10 findings (Findings
2, 7, 8, and 9) are about environmental influences rather
than genetic influences. Via genetically sensitive designs
such as twin studies, behavioral genetics has revealed
almost as much about the environment as about
genetics.
You have to elaborate a bit more if your claim is that this paper disprove environmental influences.
A second key aspect from the abstract:
Most important, heritability does not imply immutability (Plominet al., 2013).
I disagree. Take the immutability aspect highlighted. Without environmental influences, how do you cause a change? Genes can technically change during life, but I doubt thats what the study referees.
The idea that genes dictate outcomes in immutable ways is exactly what the authors of this study disagree with.
To make a direct example on the study of a particular gene and depression. If you take a person with this gene, they have (if i recall right) 6 times higher risk factor for depression compared to other people, but only if they also have had a child hood trauma. People with the gene and no such trauma has no higher risk for depression than people without the gene and no trauma. The gene has a environmental aspect to it.
Page 5:
For example, a heritability of nearly 100% implies that environmental differences that exist in the population do not have an effect on a particular phenotype assessed at a particular stage in development.
Title: Finding 2. No traits are 100% heritable. Although heritability estimates are significantly greater than 0%, they are also significantly less than 100%. As noted earlier, heritability estimates are substantial between 30% and 50%,
The study is very clear here. Environmental influences are estimated to be between 70% and 50%, and never as low as 0% for any single trait.
Further more on page 6:
Many others have noted that
no traits are 100% heritable (e.g., Plomin, 1989; Turkheimer, 2000).
My original claim was that alone the genetic factor tend to have no effect, ie, no genetic factor gives 100% heritability for a trait in behavioral science. This study support this claim. I am sorry to say that either you read the study wrong or you misinterpreted my comment.
Speaking informally, but as a professional analyst here who is unfortunately at a computer with no analysis tools setup :( but who has worked with his fair share of social, survey and demographic information.
Check your data. My first gut-instinct on seeing data like that is not "Eureka - i found a huge first-birth-order effect", but rather "huh...looks wrong, I wonder why that is?".
What do I mean "looks wrong"? Keep in mind I have no real "pony in the race" on first-born effects (although I admit I am one), but intuitively it "doesn't look like real social data looks like".
The effect is too big. Its too loud. Its too constant. Its too nice. Something else is driving it and its your job to find out what...
The first place I'd look is data quality. Have you proven your data got into your final histogram data set right? I had problems with your csv opening it in libre office...looks like it interpreted it as having some value migration between the variable in whatever you did. Could be my computer, but in my experience, if there's a problem with the csv, these kind of things correlate with other mistakes.
The second place i'd look is survey design: was there a default option, are people clicking through by default, are the response frequencies of other variables lining up as would be expected (gender, birthdays, that kind of thing). If not, why not?
If you've crossed and ticked all those, only after that would I start the analysis...but again, a pattern and effect of that size and consistency is something that you should default to needing explained in the data. Reach the conclusion that its real only after you've eliminated everything else.
It wasn't a default option (you were asked to enter into a text field your number of older brothers, older sisters, younger brothers, younger sisters).
He can't cross-reference by gender very well because his audience is overwhelmingly male, to the point where there's probably not a lot of statistical significance in the female audience.
But yes, I think that these data are very open to an "impossibly hungry judges" critique. If birth order effects were so very visible and so very strong, why haven't we noticed them before?
Anecdote time/thought experiment: and forgive me, I'm deliberately vague here.
Pretend there's a business somewhere.
Pretend they implemented a rule that said people had to enter a number/estimate into a box for a certain peice of information before they could proceed to the next box.
Pretend as an analyst you're looking at the values resulting some way down the pipe from that data entry point.
Do you think it reasonable to assume the distribution of numbers entered into that box that were invalid would be uniformally random?
If the answer is no, what numbers do you think people would enter disproportionately?
It seems tough to me to suggest that people are putting a default 0 in for older siblings but a default non-zero in for younger siblings. Why wouldn't they be consistent?
That said, I still don't believe these data. I don't know where the flaw is, but I none the less think there's a flaw. If it were a much smaller effect, it would be much more believable.
> If it were a much smaller effect, it would be much more believable.
Why do you think that?
We know that the SSC readership is in many ways quite distinct from the general population, so why do you find it surprising that it has correlations with birth order? Is it because you find it surprising that anything has correlations with birth order?
The effect would have to be smaller because most effects in psychology and sociology are pretty small. Else they would be obvious (common sense) even without field experiments.
I agree with the other comments here that it is a rather common sense effect, but it has eluded psychological research until now (which is what makes me question it). I know plenty of people who have a common sense view that birth order is important. So that part isn't missing. I can't even grasp how many times I've heard about the middle child being so different. Or being a typical little brother, etc.
For me the question is, if it is so obvious and measurable, why is this the first study that finds this obvious effect.
Most effects are small if you sample general population randomly. However, if you make a survey among basketball players, asking them for their height, you're going to find an extremely large effect. And in fact, birth order effect seem to be common wisdom too.
I like this way of approaching the problem, but I don't think it convincingly contradicts the GP's point; if participants were just entering invalid data to skip the question, then I think they would enter a similar type of number in both "# older siblings" and "# younger siblings", e.g. 0 and 0, or 100000 and 100000, or `rand(10)`.
The key observation is that I'd expect the same RNG to be used for each of the four fields.
I think you'd see much more `0`s in the fake data as well (it's a Schelling point). But if the fake-data population was disproportionately recorded as only children, that would have reduced the first-child effect, not attenuated it.
>If birth order effects were so very visible and so very strong, why haven't we noticed them before?
I'm not sure where you're from but everyone I know (including a psychologist) sees birth order effects as very real with noticable effect. Have you never seen the stats of first borns being overrepresented in management, for example? Am I misunderstanding what you mean by "haven't noticed them before"?
Another example, having older brothers is one of the most consistent correlations with homosexuality for males. Birth order effects are absolutely visible.
As the article mentions in like the first couple of paragraphs, those results haven't generally withstood replication.
But more so, the effects in the Slate Star Codex survey are extremely strong. You'd expect that an effect that strong would be part of the common wisdom, not something that has to be teased out in a psychological study.
Well, to what you just mentioned, it -seems- to be a "common wisdom" that is disregarded by scientific study. So, maybe this is a case where the study was ill-designed, but everyone took it for granted?
Was it optional though? He said some people didn't give him enough data, which makes me suspect first-borns were more likely to go "oooo this question is about me being awesome - better fill it in!" and other people to go "eh wtf I'll skip it".
All questions in the survey were optional. He had 2965 respondents for that question, out of 8077 total respondents, so that's a plausible source of bias.
> It wasn't a default option (you were asked to enter into a text field your number of older brothers, older sisters, younger brothers, younger sisters).
Is blank coerced into 0?
That would seem to explain the size of the effect.
Just a quick follow up, the reason I suggest looking at things like gender or birthday frequencies is because they're two bits of social data that have brilliant properties for getting to the bottom of this sort of things.
In practice, gender is immaculately reported and recorded compared to most other variables.
Both gender and birth days have nice reasonableness bounds and statistical properties that can be transparently reasoned about. Deviation from those nice statistical properties not only confirms for you that something is going on in your data, often the way it can deviate gives hints as to the next thread you should start chasing.
Obviously it's not perfect, not all data problems will show up there, but in practice it's an extremely low hanging fruit on which to get started, and seeing strong deviations from 50/50 statistical gender splits and predictable day/month/year type distributions should start analytical klaxons going off in your demographic noggin...
It's odd to have to point this out in this forum; the tech community has female participation rates around 25%. That doesn't somehow make statistics about this community suspicious.
Sure, if you didn't know that the base rate was skewed, you'd want to check your numbers the first time you made that measurement. But it's well-known (I suppose only by regular readers of SSC) that the SSC community is significantly above the population base rate on a whole host of metrics (self-reported IQ, transgender, % of males, autistic spectrum, etc).
It may not be 50/50, but if you didn't select for gender in your survey design, it would be a "brave assumption" that gender isn't connected to your outcome/suggested mechanism in some way...
which is why you also need to take age into account. certain age groups will have different ratios, but the standard deviation for those age groups should cover for those variances.
This. Not taking into account actual age is completely wrong. Age of the respondent is going to show a skewed result (I bet none of your readers are 10 years old...). Does that mean the older sibling is "smarter"? No, it means young people are not your audience...
Yes, absolutely. That's why you also look at things like the distribution of birth day digits, which is something you expect to be standard in almost every data collection that didn't directly use that as an explicit selection factor.
But regardless, back to gender.
Lots of groups don't have 50/50 splits. But where they don't, it's elementary to discover that they don't. Plus it's a peice of information that is traditionally very accurately recorded: recording mistakes and misreporting compared to other variables in practice is almost traditionally the lowest of any variable amongst most populations of social data.
How much they differ from 50/50, and why they differ is usually a big peice of the analytical puzzle.
Someone else pointed out "well, professional footballers all men". But that's exactly my point, if you were generally interested in discovering things analytically, and you got a set of data sources from professional footballers, you'd discover all men, and quite rightly you'd investigate and find out "yeah, gender plays a real role in professional football". There's actual mechanisms and predictions you'd eventually find.
But in this situation, where you're explaining birth order effects, we need to start hypothesising and looking for tests, falsifiable claims, and mechanisms of operation.
Now, I don't know what mechanism is at work here, but you can bet that an almost 100 make presentation rate amongst a survey that didn't explicitly select for it is highly relevant to the puzzle.
Why is it attracting these people? Are these representative males themselves? Are the females representative? Does the birth order effect only express itself in this community and these makes in these parts of the country/world/industry? What is its suggested mechanism of action that can be stated in a falsifiable way? If it was real, where else would you find it, and given our known distribution of makes in the population, how often and strong might you expect those effects to be?
Off-topic, but is this a common practice? How do analysts ensure that studies aren’t incorrectly invalidated when bad data ends up ‘looking good’? (BTW: I know little about data, so forgive my ignorance.)
The goal is to control for known biases. It’s hard, however, to discern conclusions from a dataset that is already biased. There’s very little in this to conclude effectively that “intellectual curiosity” was caused by birth order. They might be independent variables from each other on this survey born out by another variable. Or are completely spurious in nature.
One possibility that came to mind when I read his post that harmonizes both your point and his data is that the studies that have been done would almost certainly have been looking at very broad effects, on very broad populations, which results in a very averaged, fuzzy view of things. That is not a criticism, because it is a priori both plausible that there will be some effect at that scale, and that there won't be, so it's a worthy test.
But it is also possible that while broadly speaking birth order doesn't have any significant effects on things, when you go out to a population as niche as "people who read SSC and like it enough to fill out a form for 15-30 minutes just because Scott asked them too" and you slice the n-dimensional space in question with that much precision, that you will get a very, very particular slice of the world in which there are birth order effects.
This would imply that there are birth order effects, but that in general they are too weak to be picked up by a general-purpose study. However, perhaps if you magnify them in such a precise way you can see them, even though they are small. "Member of the SSC community" is a very information-rich cut of the general population and it would not be a surprise to see that poking out of the stats in many other ways.
Statistics being what they are, I believe it is completely possible for both "Birth order has no significant impact on whether you will show up in SSC's community" and "Given membership within SSC's community, birth order effects can be witnessed" to be simultaneously statistically true. Previous studies showing birth order to not matter would be testing a hypothesis much closer to the first one, Scott is obviously testing the latter.
This is merely a hypothesis that is not very complicated (in Occam's Razor terms, given the fact that "everything sorta correlates to everything" is a basic fact of the world we live in and thus using that does not really count as "multiplying entities") and fits both the facts, but not one I am claiming is certain to be true. A lot more analysis would have to be done, to a degree of rigor I doubt anyone is going to perform since nobody has the full picture and the effort to obtain the full picture is likely larger than the payoff. So let it be clear that I'm just spitballing, and aware of the fact that I'm just spitballing.
This hypothesis could well be true, but it's somewhat difficult to falsify; you can always posit an effect that only appears in the small statistically-underpowered cohort that Scott sampled, and which would be swamped by the average of the population as you start to increase the sample size to verify the effect.
As a counterpoint, Scott went the other direction in his post, arguing that the true effect was more general, but the metrics previous academics used was broken, and therefore undersold the strength of the effect they were detecting:
> I think the most likely explanation is that tests for Openness have limited validity, which makes the correlation look smaller than it really is. If being an eldest sibling increases true underlying Openness by a lot, but your score on psychometric tests for Openness only correlates modestly with true underlying Openness, that would look like being an eldest sibling only increasing test-measured-Openness a little bit.
It's simple to falsify this (though it requires some work); just do more experiments on the general population using the metric that Scott likes [1], and see if that detects a stronger birth-order effect.
Reading a random person rant about scientifying stuff, should perhaps be evenly distributed across siblings; until you realize that writing style does give away a lot about the person writing it. You can write a decently performing classifier that predicts gender (and several other demographics) from stuff they write, even from tweets, and chats. It would be stupid to think that people do not pick up the demographic clues in writing, and set their preferences accordingly.
His writing indicates he believes his readers are "more intelligent", and he believes that first borns are "more intelligent". So yeah, if you were a second born, who was more intelligent, you'd dismiss his blog as BS, and would not be counted among the survey respondents.
For that to work, you (our hypothetical more-intelligent second-born) would need to:
1. Have seen Scott express the opinion that first-born children are more intelligent.
2. Interpreted that claim in a way incompatible with your own experience of being an intelligent second-born (e.g., taken Scott to be saying first-borns are always more intelligent).
3. Been sufficiently offended (or otherwise unimpressed) by this to stop reading his blog when you would otherwise have been happy to read it.
For this to explain the apparent firstborn bias in Scott's survey respondents, thousands of potential readers would need to have done this. So, how plausible is it?
1. I've been reading Scott's blog for years and don't remember ever seeing him say anything like "first-born children are more intelligent" before this post we're discussing now. That doesn't mean he never did, and I'd be extremely unsurprised to find that he did -- but it does suggest that if he did it was easy to miss.
2. The distinction between "on average firstborns have an IQ one point or so higher than non-firstborns" and "firstborns are always smarter than not-firstborns" is not exactly subtle.
3. Well, anyone can get upset about anything, but this really doesn't seem to me like the sort of thing that would make thousands of people swear off an otherwise interesting blog in disgust.
I'm going to rate it very implausible. No way is anything remotely like this a non-negligible fraction of the explanation for the apparent firstborn bias in Scott's survey respondents.
Obviously the SSC readership is a very long way from being an unbiased sample of (say) the whole world's population. No one would expect it to be, and in fact that's the point here: a survey of people who are obviously unusual in some respects (whatever combination of quirks turns someone into a likely SSC reader) turns out to be unusual in another respect with no obvious connection, namely having substantially more firstborn children than you'd expect.
Whatever it is that makes someone more likely to read SSC, it seems like it's probably a combination of things that surely can't correlate with birth order (e.g., being a native English speaker) and, broadly speaking, personality traits (e.g., being interested in the sort of thing Scott writes).
So the results show evidence of a link between birth order and personality, and (from the survey results) apparently a strong one. Which is interesting if true. And all of this only works because the SSC readership is far from typical of the population of a whole.
So, again, what do you mean by "skewed"? And why is it a problem?
> It’s unlikely that age alone is driving these results. In sibships of two, older siblings on average were only about one year older than younger siblings. That can’t explain why one group reads this blog so much more often than the other.
It would be interesting to investigate the relationship between the age of the respondent and the effect of birth order. For example, does birth order matter less for millennials than it does for baby boomers, or vice versa?
Also would be interesting to investigate how much the age difference between siblings matter. For example, does birth order matter more if the siblings are born 1 year apart vs 10 years apart?
For an effect this prevalent and strong my first reaction is "check your data." Then I read this:
>It’s unlikely that age alone is driving these results. In sibships of two, older siblings on average were only about one year older than younger siblings.
And I really start thinking you have to check your data. The average age difference in that cohort is only one year and humans have a 9 month gestation. Something is likely wrong with your data or your sample.
> No, the difference between the average age of all older siblings taking the survey, and the average age of all younger siblings taking the survey, was one year.
The birth order effect is fascinating to me because my bias is to trust the scientific consensus, but as a parent I see such obvious patterns in my children and in the dozens of friends kids that I’ve watched over the years.
Fully agreed, its uncanny when you see it in person.
It makes sense from a genetic perspective: Similar how to allocate investment funds (primary funds in safe conservative investments, additional funds in more speculative 'moonshot' investments).
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[ 4.4 ms ] story [ 960 ms ] threadIf you have a big enough sample, you can ask if the average only child scores higher "Openness" than the average reader, or if their self-reported IQ is higher. That's a meaningful comparison I believe.
But I checked the data I received before and after I posted that, and the birth order effects are about equally strong throughout.
Of the before-posting people, 2199 had exactly one sibling, and 71.1% of those were the older.
Of the after-posting people, 776 had exactly one sibling, and 72.3% of those were older.
A t-test revealed no difference between the two groups, p = 0.527.
Regarding birth order, the "middle child" stereotype is prevalent in Western society. Did the middle child stereotype spring from some sort of effort by first-borns to keep their lower-ranked siblings in line (a la racism?)? I doubt it. The middle child stereotype probably came from hundreds of years of observations. It's a similar story for the first-born and last-born stereotypes- they weren't created out of any prejudice, but probably from hundreds of years of mothers chatting about their kids.
Like the article says, denying that the differences exist prevents us from ever finding out why (because people won't do research on something that doesn't exist). So let's acknowledge that some groups of people are different than other groups, and then respectfully do research to figure out why. The differences could be societal- perhaps first-borns are treated with more care by their parents, or they could be biological- perhaps the hormonal changes in a pregnant woman are different for each successive child, or they could be something else entirely- I had many of the same teachers as my older sister, and I often benefited from them having a pleasant experience with her, making my time in class much easier.
But anyway, the first step is acknowleding that a difference exists, and that you aren't somehow "birth order-ist" just because you acknowledge that first-born kids often outscore lower order kids on many metrics.
What is this stereotype though? I don't know about it - or about the others actually, but they were explained in the article.
I never heard anyone explain lack of success of child by saying "because he is second" or success of first as "first tend to be like it". Like, never.
Obviously this doesn't hold true for every family, and I'll acknowledge that this stereotype is may be less prevalent in cultures that tend towards small families (one or two kids).
Also, it's quite possible that in France we talk even less about that, as people "being born equal" is a really important concept here.
I don't think it should be ignored just because there are more hot-button issues that can be fixed- recruiting women and racial minorities into STEM is probably a better bang for your buck than trying to level out a 1 point difference in IQ based on birth order (how would that even happen?). Even though birth order has a low effect size, it would be nice to know why it happens and how much we could do to change it.
And then immediately the second step is acknowledging that these differences are, in most cases, too small to matter, as even Scott Alexander points out when he refers to the existing academic research.
There are few studies of birth order effects just like there are few studies of the effect of birthmarks on human psychology. There's mostly just not enough there for it to be an interesting investigative avenue.
And the whole "few studies exist because it isn't interesting" is the cycle that he's pushing to break out of. Enumerating the differences could make them interesting to psychologists, because then they might be able to determine a cause and intervene. The second to last paragraph of his post explains it more.
Matter for what, exactly? Case in point, there's a distinct physiological difference between me, a guy who has lived at almost sea-level altitude for his entire life (I'm in my late-30s now) and a guy who has lived in La Paz, Bolivia, at 3,000 m altitude: I won't be as able to physically perform at that altitude as he is, and that matters (for example if I were a professional footballer and I wanted to win a match against the Bolivian's guy team most probably I would lose, even if I were Messi, one of the best footballers ever). And I could add countless other differences between different groups of people from all over the world from the sports' world alone. That wouldn't make me a racist because I don't believe in races, but I believe (based on my past observations) that there are indeed differences between the 7 billion humans inhabiting this planet.
The analog here from Scott's article is that he mentions that this skew towards first-borns might be STEM specific. A 1.5 point difference in knowledge based (creative) careers might matter. But most people work in training based (vocational) careers, and a 1.5 point difference might not matter there.
I just said that it matters for sea-level people who have to perform physical tasks in La Paz, a populous city, nonetheless. I gave Messi's example because that was the easiest one, but I could have given an example of a Bolivian guy moving to La Paz from the country's planes area and trying to find a job physically carrying stuff in a warehouse. His rate of work would be much diminished compared to a guy born and raised in La Paz, so, presumably, his pay would also be lower. It matters because it shows that our bodies have changed and are indeed different based on certain geographical circumstances, but because some crazy guys in the late 19th-early 20th century have decided to kill millions of people based on some other differences that means that it has become tabu to discuss about this.
That doesn't make me politically correct, rather it makes me unmotivated to further explore the topic.
Can't leave to make it on his own like the younger siblings but by default don't inherit the family fortunes/business/whatever.
But as in the west we don't live in a society where the oldest inherits his fathers job/title(s) this doesn't really apply anymore.
No, the first step is acquiring sufficient high-quality data and reproducing findings.
> we don't want to talk about it.
No, some want to talk about it prematurely because it speculatively supports conclusions that fit their agenda.
> that you aren't somehow "birth order-ist" just because you acknowledge that first-born kids often outscore lower order kids on many metrics.
And yet here we are, hijacking an interesting if incomplete study for your own purpose and hiding behind "but science" whilst having an incomplete understanding of it.
I agree that good data is a pre-requisite. An online survey of blog readers isn't going to upend psychology as we know it, but Scott's findings of a heavily skewed numbers of first-borns in the survey probably can't be explained as just "online survey crap." The only "online crap" explanation I can think of is if the "first born" box was pre-filled and people changed the response for their number of siblings but didn't change the pre-filled response for birth order. This unbalanced first-born ratio is something that could be looked at in a bigger and more rigorous survey.
> some want to talk about it prematurely because it speculatively supports conclusions that fit their agenda
We have to talk about it otherwise we'll never get any data- I'm not advocating policy decisions based on incomplete research, I'm advocating discussion and follow on research. You can't do research without discussing ideas ahead of time.
> yet here we are, hijacking an interesting if incomplete study for your own purpose
I didn't hijack anything. I was making a comment that stayed on topic and is related to the post.
BTW, I'm a statistician, and have a pretty good understanding behind the science of surveys. I'm admittedly not an expert in psychology. From the HN guidelines: "Please respond to the strongest plausible interpretation of what someone says, not a weaker one that's easier to criticize. Assume good faith."
In the survey, birth order is inferred from the field that records the number of elder siblings. If the form design nudged respondants to not completing that field more than other fields (via unclear or biasing wording, ordering effects, etc) that could produce a similar outcome.
I haven't looked at the survey so no idea, but there are more potential causes than defaults.
I'm not saying there's no effect, just that right now this claimed finding seems contrary to the existing body of evidence.
This finding may well be accurate (and the existing studies in error). Alternatively it may be a mistake. Alternatively both could be true and this survey represents a special case, some kind of selection bias.
Given that this survey is yet to be peer reviewed or replicated I think the most likely explanation is a mistake, but that's just my perception of the balance of probabilities.
Reminds me of the suppressed discussion about males having a slight preference towards things while females having a slight preference towards people which caused so much of a stir at Google.
This, this, this, this, this!
People are not created equal at all! That should be obvious to anyone evaluates the world in even a cursory manner. There are material, physical, emotional and intellectual differences between any two individuals.
I have a (totally baseless and unvalidated) theory: If you accept that all people are not equal you are presented with a curious metaphysical problem when considered from a Western "Christian" perspective; why did God create both paupers and princes?--i.e., why are some born into ridiculous wealth and others crippling poverty? Eastern traditions handle this typically by some appeal to "reincarnation" and/or "karma." You can't do this in the Western view because everyone there is living to get into heaven, not escape samsara (it's funny that in some views these are actually the same thing :)
In earlier times when I debated fundamentalists, the retort would be "each is tested in his own way" or something along those lines. How entirely unsatisfying, the game is rigged and we're all not starting from the same position! For the modern, non-secular mind, it seems people would rather maintain the fiction of equality than consider the fact that the world is a profoundly un-equal place.
I'll bite though on the religious bit (I'm a practicing Christian). I think people give unsatisfying answers because a base assumption is that God can do anything. But really, there are things God cannot do, or he would cease to be God...
Add in Christ's atonement making up for all injustices and pains, the ability to choose as paramount our being, and our existence extending beyond both ends of this mortal existence. And then I think we have most of the pieces necessary to construct an answer that's not entirely dissatisfying.
I'm not here to discuss it per-say, just wanted to say that I think most (religious) people build their arguments from some unchecked assumptions that lead to unsatisfactory results.
(As a mostly irrelevant aside - if you've ever read the second MistBorn series, I think the God-like figure in that series touches well on interventions of God)
When I was still a catholic I "solved" this by assuming God put souls with more capability to survive hardships in bodies that experience more hardships. Basically the world is a level-scaling MMORPG :)
When I stopped being a catholic I just assumed there's nothing fair about universe, it's just random, so there's nothing to explain.
The fact we don't have equal chances is obvious, even people saying otherways usually know this deep down, they just won't admit it because ideology, so they might say "people are equal, but society is keeping some of us down" (clearly not the only factor - see psychological development problems), or "people are equally talented at different things, some of us don't get to realize these talents" - which might be true, for general enough definition of talent, but is quite unlikely (if nobody's supervising the distribution of talents - how do you ensure everybody's got the same amount?). And even if it's true - the definition has to be so general that in practice it doesn't matter.
Interestingly, if you an understand the synthesis of eastern metaphysical concepts such as "maya" (illusion), "karma" (causation) and their logical implications such as reincarnation, you arrive at a similar conclusion -- the world is essentially a game (meant to be enjoyed, a journey, a sport to be reveled in), which scales your instance based on your karma! There's respawning too :)
Choose your own adventure!
Just thought I'd drop a book recommendation here: "The Monk and the Philosopher" - Jean-François Revel and Matthieu Ricard [0]. A much younger, atheist, science-absolutionist (?-haha) me had his mind blown by this text. It made me seriously question my world view (which would be later be shattered by a friend with considerable philosophical talent). I do not currently identify as a Buddhist, and I'm not sure how it would be received now, but it certainly was useful in breaking a certain science-dogma in me.
edit: punctuation, book recommendation
[0] https://www.amazon.com/Monk-Philosopher-Father-Discuss-Meani...
> The differences could be societal- perhaps first-borns are treated with more care by their parents, or they could be biological- perhaps the hormonal changes in a pregnant woman are different for each successive child, or they could be something else entirely
No one brought it up directly, but I can't help but think that some of this thread has undertones of the Damore discussion, which drives the argument from:
Societal changes we could make - to - these things (sorta kinda maybe based on pseudoscience) might not be societal and shouldn't be addressed (or at least not in the way they currently are).
I tend to be strongly in the former camp, which it sounds like you could be too. But let's not conflate those two separate conversations.
Race and gender has a profound effect on your prospects, but not in a way we can't fix.
Romans 9 is rather controversial in Christianity these days. A lot of people will tell you it doesn't mean what it seems to be saying. But if you take it on face value, it explicitly acknowledges that the game is rigged. God makes different people to serve his different purposes, and that is the way it is meant to be.
Some clarity around "God's purpose" would be helpful.
To be all-powerful means you have the ability to effect any and all ends that you desire. It means you can realize all your purposes. If one doesn't have any desires (i.e., purposes), I'm not sure it would mean anything to say one is all-powerful.
If you accept that all people are not equal, then you are presented with a number of curious metaphysical problems. The big one is, how do you limit the damage caused by the lessers?
For my brother and me it was the same, except he was really narrowly interested. He left a very bad impression with every sports and arts teacher I had. And with sports and arts there's no hard proof that you're better than the prejudice.
During the hundreds of years of observations, what were social conditions like? What social classes were studied? How did the high rate of infant and maternal mortality affect those conditions? The main change in successive children was that some of them died.
The second-to-last step is deciding what you want to do with this information.
The problem with stereotypes isn't just when they are "hateful" or "inaccurate"; the problem with stereotypes is also when they are used to deny individual variation.
* doesn't control whether the not-first-borns are outside the target demographic (too old or too young)
* doesn't look at children without siblings
* more importantly: is just a cross section, so no causal relationships can be gleaned from that
* also highly problematic: is self-selecting, with no discussion of the distribution of people not participating. With a poll question like that that alone invalidates every result, as obviously it invites bias towards readers who deem themselves smarter than their siblings
* is not discussing, and controlling for, alternative explanations for the observed result
All in all the margin of error is almost certainly a multiple of the effect size, thus rendering the results useless. Which they are anyway, because you can only answer a question like the one given in the article with longitudinal studies.
It's interesting nevertheless.
I'd never heard of the supposed higher intelligence of first born, but I've heard a lot about the sporting side and anecdotally I've noticed it too (I am the oldest sibling in my family).
[1] https://www.ncbi.nlm.nih.gov/pubmed/20435800
If the survey took place on a gun enthusiast website:
- Fair claim: first borns are more likely to be gun enthusiasts
- Far fetched claim: first borns have stronger personalities
I'm not just assuming it, I'm saying that two analyses showed it was the only trait that mattered, and then it suffices to explain the current data.
I preach cautiousness in the name of finding the objective truth. One should be careful when testing a specific group of people.
Single points aren't anti-points to statistical effects. Now if you happened to have a thousand friends that where also the youngest of 6 and happened to test higher on IQ scores, that would be weird. For more than one reason.
Or, again, perhaps there is a large part of cultural bias ("eldest/heir" of the family being assumed as better) so given more attention/resources... And that since I'm from a family with a single mother (who didn't have time/inclination for that) I was spared that?
In any case, I think making up "exists and are strong" conclusions without taking into account more parameters is simplistic at best...
Alternatively birth distance (time between births) or age of mother are the actual correlate. We do not know.
First. The word is weird.
Second. No, you would not assume that. Why would you assume that? You could also with equal validity assume that something is present in the mother with the first-born that is absent in all the rest. You could also assume the study is hokum and missed something obvious.
Third. This “Single points aren't anti-points to statistical effects.” is _exactly_ why it isn't weird. Even supposing there is some statistically distributed effect you as a single point is a total non-issue. You are not special. Do get back to me if you've three heads or something.
Fourth. To think it is weird suggests you are in fact not as smart as you think you are. :)
Fifth. To continue arguing the point when it has been explained to you why you are wrong is again indicative of not being as smart as you think you are. :) :)
Second. Oops, no seconds here, First is usually enough for me to lose interest in said people.
Big5 is a valid personality test-- it gets decent test/re-test scores, but it's still weak. Myers-Briggs fails because, despite being very similar to the Big5, it doesn't have good enough test/re-test scores.)
Scott cites another study that says when you test openness properly, you get a wider distribution. So if you pair those two together, you get a decent sized effect. Maybe.
I think it's more likely a measurement error, or some subtle statistical effect caused by a combination of probability skewing and demographic changes.
Can you elaborate?
https://docs.google.com/spreadsheets/u/1/d/e/2PACX-1vRrops3J...
Consider just the bins 20 (ages 10-20), 30 (ages 20-30) and 40 (ages 30-40). We can see that, of the three groups, teens are by far the least likely of these groups to read the blog, and people in their 20s are the most likely.
Now consider two groups of two-sibling families that lie within this range, where one sibling is in one bin, and the other the next. E.g. the first group where one is a teenager, the first-born is in their twenties, and the second where one is in their 20s, and the first-born is their 30s.
Case 1: If you take a random family from the [teen, 20s] group, how likely is it that the reader from this family is younger or first-born sibling? Since those in their 20s are much more likely to read the blog, it is much more likely that the reader is in their 20s, and is the first-born.
Case 2: Now take a random family from the [20s, 30s] group. How likely is it that the reader is the younger sibling or the first-born? In this case, because readers in their 20s are more common than readers in their 30s, it is more likely that the reader is the younger sibling.
However, the ratio of readers in their 30s to readers in their 20s is much closer than that between the 20s and teens. This makes it more likely in that in case 2 that the reader is still the first-born. Therefore, if the number of families in each group is equal, we would expect to see, in aggregate, more first-born readers than younger siblings.
I'm not saying that this is happening in the actual data, you'd need to do more analysis, and probably need more data about the ages of siblings, or that it is a significant enough effect to cause the result found. But it demonstrates that statistical analysis can involve subtle effects that are not obvious without careful consideration. As such, we should be very wary of making any conclusions about causes, either birth order or anything else.
Personally, I mulled over it for a while and I don't see any mere "statistical" effect that's plausible. I think we are forced to conclude there's a psychological difference with firstborns.
Yet, "oldest children are more conservative, youngest children are more creative, etc." and the oldest being more intellectually curious describes them perfectly.
So, anecdotally, my study of 1 data point says it's probably nuture and not nature.
[1] https://news.ycombinator.com/item?id=16105462
So you're more likely to encounter a first born in the real world than any nth born, since some families will have only had one child.
Would like to hear more details to that claim. When ever I read about genetic factors (For example on the topic of depression), I keep hearing that without the environmental factors the genetic indicators loose their predictive power. Genetic factors in behavioral science make a person more effected by environmental factors, but alone the genetic factor tend to have no effect.
To take the explicit example in the article. Is there an measurable effect in adult life that correlate to the amount parents focus and dedicate time to them as child? In rats I have heard enough studies to show a very strong correlation between stress in adult life and time that the rat got groomed as young by the mother. Could it be so simple that parents spend a bit more time/focus with the first child during the first few years, while the second child receive a bit less since there is now two children and the parents are a bit more experienced and feel more secure in parenting. While rats and humans are not identical, it is a strong hint that "parenting style" might carry an effect into adult life.
Source: https://www.gwern.net/docs/genetics/2016-plomin.pdf
Although heritability estimates are significantly greater than 0%, they are also significantly less than 100%. As noted earlier, heritability estimates are substantial between 30% and 50%.... No traits are 100% heritable (e.g., Plomin, 1989; Turkheimer, 2000).
In particular, "all psychological traits show significant and substantial genetic influence" mostly contradicts your comment, also "the heritability of intelligence increases throughout development" - i.e. environmental factors (parenting) matter when kids is young, but less so when they turn into adults.
[1] https://www.gwern.net/docs/genetics/2016-plomin.pdf
Finally, we note that 4 of the top 10 findings (Findings 2, 7, 8, and 9) are about environmental influences rather than genetic influences. Via genetically sensitive designs such as twin studies, behavioral genetics has revealed almost as much about the environment as about genetics.
You have to elaborate a bit more if your claim is that this paper disprove environmental influences.
A second key aspect from the abstract:
Most important, heritability does not imply immutability (Plominet al., 2013).
Not at all, but I think it disproves this part:
> but alone the genetic factor tend to have no effect
The idea that genes dictate outcomes in immutable ways is exactly what the authors of this study disagree with.
To make a direct example on the study of a particular gene and depression. If you take a person with this gene, they have (if i recall right) 6 times higher risk factor for depression compared to other people, but only if they also have had a child hood trauma. People with the gene and no such trauma has no higher risk for depression than people without the gene and no trauma. The gene has a environmental aspect to it.
Page 5: For example, a heritability of nearly 100% implies that environmental differences that exist in the population do not have an effect on a particular phenotype assessed at a particular stage in development.
Title: Finding 2. No traits are 100% heritable. Although heritability estimates are significantly greater than 0%, they are also significantly less than 100%. As noted earlier, heritability estimates are substantial between 30% and 50%,
The study is very clear here. Environmental influences are estimated to be between 70% and 50%, and never as low as 0% for any single trait.
Further more on page 6: Many others have noted that no traits are 100% heritable (e.g., Plomin, 1989; Turkheimer, 2000).
My original claim was that alone the genetic factor tend to have no effect, ie, no genetic factor gives 100% heritability for a trait in behavioral science. This study support this claim. I am sorry to say that either you read the study wrong or you misinterpreted my comment.
Check your data. My first gut-instinct on seeing data like that is not "Eureka - i found a huge first-birth-order effect", but rather "huh...looks wrong, I wonder why that is?".
What do I mean "looks wrong"? Keep in mind I have no real "pony in the race" on first-born effects (although I admit I am one), but intuitively it "doesn't look like real social data looks like".
The effect is too big. Its too loud. Its too constant. Its too nice. Something else is driving it and its your job to find out what...
The first place I'd look is data quality. Have you proven your data got into your final histogram data set right? I had problems with your csv opening it in libre office...looks like it interpreted it as having some value migration between the variable in whatever you did. Could be my computer, but in my experience, if there's a problem with the csv, these kind of things correlate with other mistakes.
The second place i'd look is survey design: was there a default option, are people clicking through by default, are the response frequencies of other variables lining up as would be expected (gender, birthdays, that kind of thing). If not, why not?
If you've crossed and ticked all those, only after that would I start the analysis...but again, a pattern and effect of that size and consistency is something that you should default to needing explained in the data. Reach the conclusion that its real only after you've eliminated everything else.
He can't cross-reference by gender very well because his audience is overwhelmingly male, to the point where there's probably not a lot of statistical significance in the female audience.
But yes, I think that these data are very open to an "impossibly hungry judges" critique. If birth order effects were so very visible and so very strong, why haven't we noticed them before?
Pretend there's a business somewhere.
Pretend they implemented a rule that said people had to enter a number/estimate into a box for a certain peice of information before they could proceed to the next box.
Pretend as an analyst you're looking at the values resulting some way down the pipe from that data entry point.
Do you think it reasonable to assume the distribution of numbers entered into that box that were invalid would be uniformally random?
If the answer is no, what numbers do you think people would enter disproportionately?
That said, I still don't believe these data. I don't know where the flaw is, but I none the less think there's a flaw. If it were a much smaller effect, it would be much more believable.
Why do you think that?
We know that the SSC readership is in many ways quite distinct from the general population, so why do you find it surprising that it has correlations with birth order? Is it because you find it surprising that anything has correlations with birth order?
For me the question is, if it is so obvious and measurable, why is this the first study that finds this obvious effect.
The key observation is that I'd expect the same RNG to be used for each of the four fields.
I think you'd see much more `0`s in the fake data as well (it's a Schelling point). But if the fake-data population was disproportionately recorded as only children, that would have reduced the first-child effect, not attenuated it.
I'm not sure where you're from but everyone I know (including a psychologist) sees birth order effects as very real with noticable effect. Have you never seen the stats of first borns being overrepresented in management, for example? Am I misunderstanding what you mean by "haven't noticed them before"?
But more so, the effects in the Slate Star Codex survey are extremely strong. You'd expect that an effect that strong would be part of the common wisdom, not something that has to be teased out in a psychological study.
LMGTFY
https://scholar.google.com/scholar?q=birth+order+effects
Is blank coerced into 0?
That would seem to explain the size of the effect.
In practice, gender is immaculately reported and recorded compared to most other variables.
Both gender and birth days have nice reasonableness bounds and statistical properties that can be transparently reasoned about. Deviation from those nice statistical properties not only confirms for you that something is going on in your data, often the way it can deviate gives hints as to the next thread you should start chasing.
Obviously it's not perfect, not all data problems will show up there, but in practice it's an extremely low hanging fruit on which to get started, and seeing strong deviations from 50/50 statistical gender splits and predictable day/month/year type distributions should start analytical klaxons going off in your demographic noggin...
Sure, if you didn't know that the base rate was skewed, you'd want to check your numbers the first time you made that measurement. But it's well-known (I suppose only by regular readers of SSC) that the SSC community is significantly above the population base rate on a whole host of metrics (self-reported IQ, transgender, % of males, autistic spectrum, etc).
Edit: to clarify which point I was referring to
But regardless, back to gender.
Lots of groups don't have 50/50 splits. But where they don't, it's elementary to discover that they don't. Plus it's a peice of information that is traditionally very accurately recorded: recording mistakes and misreporting compared to other variables in practice is almost traditionally the lowest of any variable amongst most populations of social data.
How much they differ from 50/50, and why they differ is usually a big peice of the analytical puzzle.
Someone else pointed out "well, professional footballers all men". But that's exactly my point, if you were generally interested in discovering things analytically, and you got a set of data sources from professional footballers, you'd discover all men, and quite rightly you'd investigate and find out "yeah, gender plays a real role in professional football". There's actual mechanisms and predictions you'd eventually find.
But in this situation, where you're explaining birth order effects, we need to start hypothesising and looking for tests, falsifiable claims, and mechanisms of operation.
Now, I don't know what mechanism is at work here, but you can bet that an almost 100 make presentation rate amongst a survey that didn't explicitly select for it is highly relevant to the puzzle.
Why is it attracting these people? Are these representative males themselves? Are the females representative? Does the birth order effect only express itself in this community and these makes in these parts of the country/world/industry? What is its suggested mechanism of action that can be stated in a falsifiable way? If it was real, where else would you find it, and given our known distribution of makes in the population, how often and strong might you expect those effects to be?
Randomized double-blind studies
peer reviewed question sets
longitudinal cohorts
The goal is to control for known biases. It’s hard, however, to discern conclusions from a dataset that is already biased. There’s very little in this to conclude effectively that “intellectual curiosity” was caused by birth order. They might be independent variables from each other on this survey born out by another variable. Or are completely spurious in nature.
But it is also possible that while broadly speaking birth order doesn't have any significant effects on things, when you go out to a population as niche as "people who read SSC and like it enough to fill out a form for 15-30 minutes just because Scott asked them too" and you slice the n-dimensional space in question with that much precision, that you will get a very, very particular slice of the world in which there are birth order effects.
This would imply that there are birth order effects, but that in general they are too weak to be picked up by a general-purpose study. However, perhaps if you magnify them in such a precise way you can see them, even though they are small. "Member of the SSC community" is a very information-rich cut of the general population and it would not be a surprise to see that poking out of the stats in many other ways.
Statistics being what they are, I believe it is completely possible for both "Birth order has no significant impact on whether you will show up in SSC's community" and "Given membership within SSC's community, birth order effects can be witnessed" to be simultaneously statistically true. Previous studies showing birth order to not matter would be testing a hypothesis much closer to the first one, Scott is obviously testing the latter.
This is merely a hypothesis that is not very complicated (in Occam's Razor terms, given the fact that "everything sorta correlates to everything" is a basic fact of the world we live in and thus using that does not really count as "multiplying entities") and fits both the facts, but not one I am claiming is certain to be true. A lot more analysis would have to be done, to a degree of rigor I doubt anyone is going to perform since nobody has the full picture and the effort to obtain the full picture is likely larger than the payoff. So let it be clear that I'm just spitballing, and aware of the fact that I'm just spitballing.
As a counterpoint, Scott went the other direction in his post, arguing that the true effect was more general, but the metrics previous academics used was broken, and therefore undersold the strength of the effect they were detecting:
> I think the most likely explanation is that tests for Openness have limited validity, which makes the correlation look smaller than it really is. If being an eldest sibling increases true underlying Openness by a lot, but your score on psychometric tests for Openness only correlates modestly with true underlying Openness, that would look like being an eldest sibling only increasing test-measured-Openness a little bit.
It's simple to falsify this (though it requires some work); just do more experiments on the general population using the metric that Scott likes [1], and see if that detects a stronger birth-order effect.
[1]: https://www.researchgate.net/publication/230787941_Construct...
1. Have seen Scott express the opinion that first-born children are more intelligent.
2. Interpreted that claim in a way incompatible with your own experience of being an intelligent second-born (e.g., taken Scott to be saying first-borns are always more intelligent).
3. Been sufficiently offended (or otherwise unimpressed) by this to stop reading his blog when you would otherwise have been happy to read it.
For this to explain the apparent firstborn bias in Scott's survey respondents, thousands of potential readers would need to have done this. So, how plausible is it?
1. I've been reading Scott's blog for years and don't remember ever seeing him say anything like "first-born children are more intelligent" before this post we're discussing now. That doesn't mean he never did, and I'd be extremely unsurprised to find that he did -- but it does suggest that if he did it was easy to miss.
2. The distinction between "on average firstborns have an IQ one point or so higher than non-firstborns" and "firstborns are always smarter than not-firstborns" is not exactly subtle.
3. Well, anyone can get upset about anything, but this really doesn't seem to me like the sort of thing that would make thousands of people swear off an otherwise interesting blog in disgust.
I'm going to rate it very implausible. No way is anything remotely like this a non-negligible fraction of the explanation for the apparent firstborn bias in Scott's survey respondents.
https://goo.gl/forms/8bmb7dwWyBtS5nDM2
And it is pretty obvious the sample is bias, though take a look to see for yourself and comment if you notice anything too.
Sure, who's claiming otherwise?
Pretty skewed results.
Obviously the SSC readership is a very long way from being an unbiased sample of (say) the whole world's population. No one would expect it to be, and in fact that's the point here: a survey of people who are obviously unusual in some respects (whatever combination of quirks turns someone into a likely SSC reader) turns out to be unusual in another respect with no obvious connection, namely having substantially more firstborn children than you'd expect.
Whatever it is that makes someone more likely to read SSC, it seems like it's probably a combination of things that surely can't correlate with birth order (e.g., being a native English speaker) and, broadly speaking, personality traits (e.g., being interested in the sort of thing Scott writes).
So the results show evidence of a link between birth order and personality, and (from the survey results) apparently a strong one. Which is interesting if true. And all of this only works because the SSC readership is far from typical of the population of a whole.
So, again, what do you mean by "skewed"? And why is it a problem?
It mostly deals with debunking common views on parent->child effects, but includes some material on birth order effects.
[1] https://jamesclear.com/book-summaries/nurture-assumption
It would be interesting to investigate the relationship between the age of the respondent and the effect of birth order. For example, does birth order matter less for millennials than it does for baby boomers, or vice versa?
Also would be interesting to investigate how much the age difference between siblings matter. For example, does birth order matter more if the siblings are born 1 year apart vs 10 years apart?
>It’s unlikely that age alone is driving these results. In sibships of two, older siblings on average were only about one year older than younger siblings.
And I really start thinking you have to check your data. The average age difference in that cohort is only one year and humans have a 9 month gestation. Something is likely wrong with your data or your sample.
> No, the difference between the average age of all older siblings taking the survey, and the average age of all younger siblings taking the survey, was one year.
It’s hard to reconcile.
It makes sense from a genetic perspective: Similar how to allocate investment funds (primary funds in safe conservative investments, additional funds in more speculative 'moonshot' investments).
Birth order is real and parenting is not data science.
Remember the easy birth order question? How many pictures of you do your parents have (pr take)? If u r a FB many! Less and less as kids continue