Question

Suppose a study of college students in Sweden estimates heritability of IQ to be 0.8. Based on this evidence, a school board in a struggling urban school district in the United States concludes that improving teaching methods and the physical conditions of schools is useless because intellectual achievement is determined almost entirely by genes and relatively little by the educational environment. Provide 2 critiques of this conclusion.

Answer 1

The school board's decision is based on at least two major misconceptions about heritability.

1. The first misconception is that estimates of heritability are universal, so that an estimate of heritability in one population can be used to estimate it in another population. whereas, an estimate of heritability can only apply to the population that was measured in the study.

2. A second major misconception is that high heritability indicates that the environment is not that important to the trait of interest. whereas, a high heritability indicates only that there is relatively more genetic variance than environmental variance contributing to differences in the trait. If the environment is poor uniformly around the school district and there is at least some genetic variation, then heritability would be high. although, this does not mean that performance can't be improved by enriching the environment.