Heritability Coefficients: When Will Text Books Catch Up?
Eric Turkheimer reviewed Jay Joseph's The Trouble With Twin Studies: A Reassessment of Twin Research in the Social and Behavioral Sciences. Heritability is often discussed in psychology classes and textbooks. For example, in Introduction to Psychology texts, heritability coefficients are often discussed for several issues including intelligence and psychological disorders. The Introduction to Psychology text that I use spends two pages discussing the heritability of IQ scores, complete with the ubiquitous figure showing the correlations between twins reared together, twins reared apart, unrelated children raised together, and unrelated children raised apart (Similar graphs were in Intro texts when I was in college!) One thing I do whenever my classes cover such information, is to emphasize that genes can influence our choice of environment and that environment can influence how genes influence our behavior, so that it is very difficult to disentangle genetic and environmental effects. In all fairness to my Intro text, the authors note this also.
Given Jay Joseph's book and Turkheimer's review, both of which suggest that these coefficients really do not provide much information, is it time to eliminate such discussions from textbooks?
By Eric Turkheimer
PsycCRITIQUES, 2015 Vol 60(40)