The relationships among intelligence, race, human development, and genetics are among the most important topics for students of inequality. These topics are also sites for recurring ideological battles, most recently involving Jason Richwine’s research on Hispanic immigration to the US.
There has been a persistent argument that intelligence is more or less impervious to environmental intervention, but this is not the consensus of recent research. So if the last time you paid attention to psychological research on intelligence, you need to catch up. Here’s a quick way to do it.
This is the abstract from a superb recent summary article by leading psychologists Richard Nisbett and Eric Turkheimer and several other noted social scientists.
We review new ﬁndings and new theoretical developments in the ﬁeld of intelligence. New ﬁndings include the following: (a) Heritability of IQ varies signiﬁcantly by social class. (b) Almost no genetic polymorphisms have been discovered that are consistently associated with variation in IQ in the normal range. (c) Much has been learned about the biological underpinnings of intelligence. (d) “Crystallized” and “ﬂuid” IQ are quite different aspects of intelligence at both the behavioral and biological levels. (e) The importance of the environment for IQ is established by the 12-point to 18-point increase in IQ when children are adopted from working-class to middle-class homes. (f) Even when improvements in IQ produced by the most effective early childhood interventions fail to persist, there can be very marked effects on academic achievement and life outcomes. (g) In most developed countries studied, gains on IQ tests have continued, and they are beginning in the developing world. (h) Sex differences in aspects of intelligence are due partly to identiﬁable biological factors and partly to socialization factors. (i) The IQ gap between Blacks and Whites has been reduced by 0.33 SD in recent years. We report theorizing concerning (a) the relationship between working memory and intelligence, (b) the apparent contradiction between strong heritability effects on IQ and strong secular effects on IQ, (c) whether a general intelligence factor could arise from initially largely independent cognitive skills, (d) the relation between self-regulation and cognitive skills, and (e) the effects of stress on intelligence.