Science confirms: Cats help you only when there's something in it for them (scientificamerican.com)

I could have told you that, anecdotally.

I can’t find a link to the study in the article.

The article on its own does not corroborate its premise (they haven’t described a situation where cat’s have “something in it for them”) and the experiment as described was frankly ridiculous and had a small sample size.

Thus confirming what cat owners have already known for thousands of years.