Rude research
Bryan Caplan says intelligence research is very unpopular because it looks so bad to call half of people stupider than average, let alone stupid outright. Calling people stupid is rude.
But if this is the main thing going on, many other kinds of research should be similarly hated. It’s rude to call people lazy, ugly bastards whose mothers wouldn’t love them. Yet there is little hostility regarding research into conscientiousness, physical attractiveness, parental marriage status, or personal relationships. At least as far as I can tell. Is there? Or what else is going on with intelligence?
> But it's generally perceived that lazy is a choice whereas intelligence is a god-given quality.
Indeed, to the point where people seem to be quite surprised when I tell them that Conscientiousness turns up as being about as heritable as IQ in the twin studies, stable over a lifetime (only increasing somewhat with age), and there are no established interventions increasing it I have been able to find. These points have not been widely advertised, to say the least, and active researchers in the area like Duckworth are definitely towards the environmental end of the spectrum.
Of course, part of the problem here is simply that some of these traits simply don't have as much available research. For example, OCEAN/Big Five was only really nailed down in the '80s, while IQ dates back more than half a century before that, and it's difficult to infer any Big Five factors reliably from existing large-scale datasets (either cross-sectional or longitudinal) - because a lot of psychology tasks and academic-style tests are g-loaded you can piggyback on all sorts of datasets like military enlistments going back many decades, but you can't do anything comparable for Big Five. (How has a population's Conscientiousness changed over the 20th century? No idea. Do hispanics have different Big Five profiles on average? No idea. etc)
Satoshi Kanazawa would disagree that there is little hostility regarding research into physical attractiveness.
As your first commenter noted, it's all about race. If you say that conscientiousness is relatively fixed in people before they reach adulthood, and that higher conscientiousness has positive social results, without mentioning race, very few people will attack you. If you explicitly state that conscientiousness varies by racial group, and therefore (even if this you only imply, rather than conclude) racial economic equality is not likely to be achievable, you'll attract a firestorm of opprobrium.