Something I think about a lot when I see hypotheses based on statistical trends of somewhat obscure variables: I’ve heard it claimed that at one point in Finland, it was really hard to get a disability pension because of depression or other mental health problems, even though it was obvious to many doctors that their patients were too depressed to work. So then some doctors would diagnose those people with back pain instead, since it sounded more like a “real” condition while also being impossible to disprove before ultrasound scans got more common.
I don’t know how big that effect was in practice. But I could imagine a world where it was significant and where someone noticed a trend of back pain diagnoses getting less common while depression diagnoses got more common, and postulating some completely different explanation for the relationship.
More generally, quite a few statistics are probably reporting something different from what they seem to be about. And unless you have deep knowledge about the domain in question, it’ll be impossible to know when that’s the case.
Thank you! People keep mentioning Panksepp’s work but I had never gotten around reading it; this was a very nice summary. The described mechanisms felt very plausible and interesting.
This has been disputed since then.