Friday, May 10, 2013

What did I tell ya?

Intelligence is real. It does vary across the population. It has consequences.

If you see a psychologist studying intelligence, be interested in it, by all means! This is one of the things they often speak to thoughtfully.

If you see any non-psychologist take a deep interest in measuring the differences in intelligence between socially constructed groups, particularly visibly identifiable and historically oppressed socially constructed groups - be very suspicious.

This is what I propose: economists should, as a general rule, throw intelligence tests on the right hand side of their models when they have the opportunity to because God knows we need to control for any heterogeneity we can. But then economists should, as a general rule, basically ignore it.

Generally speaking we are not qualified to talk all that much about it.


  1. I think the problem lies in that we have been down this road before with making policy based on what would later be seen as false assumptions about IQ. Goddard was a psychologist as were others and their research was used to set immigration policy and even laws for forced sterilization. I believe in free inquiry, but one has to ask why these same idea keep coming up only to be shown false yet some continue to put effort into them.

    1. I'm not sure what you're referring to. It seems to be a fairly robust finding that there are statistically significant differences in IQ between ethnic groups and social classes and that IQ is inter-generationaly correlated. Clearly, there has been (and will continue to be) some bad research, but you seem to be implying that something specific in this case is the recurrence of a theory which was previously debunked. Can you be more specific?

  2. A few points here (a little late, and also WRT your prior post on this issue):

    If IQ is highly determined by genetics (I defer to the geneticists on this):
    I believe current research shows it's about 50% genetics, 50% environment (most of the latter being non-normative social experience, that is, not the parents)

    IQ is messy, messy, messy. It is a pain to operationalize. Many times, IQ is defined as "general intelligence" -- but what is intelligence? Well, whatever intelligence tests measure.

    Other hitches: IQ tests were primarily, if not entirely, developed in the Western world, America in particular. How can we -- unless we are narcissistic ego centrists -- assume that what our society considers is intelligence could really generalize across cultures? And indeed, cross-cultural research pretty routinely reveals that different cultures prioritize different aspects of the human experience; many cultures have words for concepts that are not prominent/discussed in American society. So we might expect cross-cultural differences in scores on IQ tests; that doesn't mean necessarily that people differ on "intelligence", broadly construed. That just means it's ridiculous to expect measurement invariance of a western concept across all cultures.

    And also, often, IQ tests are standardized around 100. Constantly standardizing test scores makes it a little difficult to look at changes over time.

    Finally, we know that tests -- especially IQ tests -- test both "intelligence", but, to a large extent, also the ability to take tests. This is why, even within the US, we have sub-group differences in IQ. Because different groups have different access to the experiences necessary to develop testing competence. Now, we are working to develop culturally-ungrounded IQ tests (such as the Hannon-Daneman test or the Siena reasoning test), and these tests do help mitigate/decrease sub-group differences in American samples. But, you can see . . . this is a hot mess.

    I think IQ is one of the most tricky areas of inquiry in psychology, actually, because in normal everyday conversation we all think we have a sense of what it means, but psychometrically it's fairly problematic. Which does not mean we can ignore it -- it's a great concept and a lot of great work has been done on it! -- but it does mean we have to discuss it in as many forums as possible!


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