Survey of expert opinion on intelligence

— (5 min read)

The title refers to a survey regularly cited as an indicator of expert opinion on questions of race and intelligence, distributed mainly to psychologists and reported by Heiner Rindermann, David Becker, and Thomas R. Coyle. The survey is not a credible indicator of expert opinion.

An example of how it comes up: in support of a claim that “human biodiversity”a a "Human biodiversity" focuses on genetic variation, particularly between races, as a causal factor in disparate social outcomes. It's often labeled a euphemism for scientific racism. I've found that reputation to be deserved. “is probably partially correct or at least very non-provably not-correct”, Scott Alexander cited a post by Steve Sailer about the survey: Survey of psychometricians finds iSteve [Sailer’s Unz Review blog at the time] one of 3 best journalistic outlets in the world for intelligence coverage. Besides the result in the title, that post also calls out the average response to “What are the sources of U.S. black-white differences in IQ?” of 47% genetic (SD=31%).

These results are based on the authors’ “Expert Questionnaire on Cognitive Ability”, administered as an online survey in 2013–2014, distributed by email invitations to authors who had published in selected psychology journals covering cognitive ability and to members of the International Society for Intelligence Research. It was also announced at the annual ISIR conference and posted to the website for the International Society for the Study of Individual Differences.

This is not obviously the best net to cast to find experts on these questions—fewer than half of respondents who stated a field of study fell under “Intelligence and related”, and only four were in “Genetics”. In any case, the authors have published three papers based on their data, on international differences, the Flynn effect, and controversial issues.b b The last of these wasn't published until 2020, which is curious. I'd love to read the reviewer comments.

The main problem is that response rates make it all but impossible to interpret this survey as reflecting the views of even its own pool of experts. The response rate for the survey was about 20% (265 of 1345), and it was below 8% (102) for every individual question on which data was published across the three papers, with large variation between questions.

For example, respondents attributed the heritability of U.S. black-white differences in IQ 47% on average to genetic factors. On similar questions about cross-national differences, respondents on average attributed 20% of cognitive differences to genes. On the U.S. question, there were 86 responses, and on the others, there were between 46 and 64 responses.

Meanwhile, Steve Sailer’s blog was rated highest for accuracy in reporting on intelligence research—by far, not even in the ballpark of sources that got more ratings (those sources being exactly every mainstream English-language publication that was asked about). It was rated by 26 respondents.c c The only other outlet with a positive average rating was also hosted by the Unz Review. The authors' only comment on the subject is to suggest a third Unz Review blog: "Unfortunately, the survey did not consider James Thompson's blog, Psychological Comments, which was just beginning when the survey was administered."

The underlying data isn’t available, but this is all consistent with the (known) existence of a contingent of ISIR conference attendees who are likely to follow Sailer’s blog and share strong, idiosyncratic views on specifically U.S. racial differences in intelligence.

More cynically, this contingent has a history of putting their thumb on the scales to make their work seem more mainstream than it is. Part of their project is maintaining an appearance of legitimacy without exposing their network of authorship, review, and publishing to the standards of the broader scientific community. Overrepresenting them was a predictable outcome of distributing this survey, as they would be particularly eager for their views to be counted. Heiner Rindermann in particular, the first author on these papers, can hardly have failed to consider their existence.

I don’t know if I believe the cynical version, but if it’s not what they intended, they still nailed it. There are lots of questions on this survey, but you only ever hear about a choice few—those that best make the “human biodiversity” position sound like a live hypothesis with broad support.d d I originally wrote about all this in a footnote in a previous post, but it keeps coming up, so I figure it's worth expanding into a standalone version.