Gifted Issues Discussion homepage Forums General Discussion Equal Opportunity and Meritocracy

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The most important point about equality of opportunity from a genetic perspective is that equality of opportunity does not translate to equality of outcome. If educational opportunities were the same for all children, would their outcomes be the same in terms of school achievement? The answer is clearly ‘no’ because even if environmental differences were eliminated genetic differences would remain.

What follows from this point is one of the most extraordinary implications of genetics. Instead of genetics being antithetical to equal opportunity, heritability of outcomes can be seen as an index of equality of opportunity. Equal opportunity means that environmental advantages and disadvantages such as privilege and prejudice have little effect on outcomes. Individual differences in outcomes that remain after systematic environmental biases are diminished are to a greater extent due to genetic differences. In this way, greater educational equality of opportunity results in greater heritability of school achievement. The higher the heritability of school achievement, the less the impact of environmental advantages and disadvantages. If nothing but environmental differences were important, heritability would be zero. Finding that heritability of school achievement is higher than for most traits — about 60 percent in Western countries — suggests that there is substantial equality of opportunity.

Environmental differences account for the remaining 40 percent of the variance. Does this imply inequality of opportunity? To the extent that environmental influences are non‐shared, this means that they are not caused by systematic inequalities of opportunity. However, genetic research on primary and secondary school achievement is an exception to the rule that environmental influences are non‐shared. For school achievement, half of the environmental influence — 20 percent of the total variance — is shared by children attending the same school. This finding implies that up to 20 percent of the variance in school achievement could be due to inequalities in school or home environments, although this effect mostly washes out by the time children go to university.

The third finding, about the nature of nurture, is also relevant to understanding the relationship between equal opportunity and outcomes. What look like systematic environmental effects in fact reflect genetic differences. For example, the socioeconomic status of parents is correlated with their children’s educational and occupational outcomes. This correlation has been interpreted as if it is caused environmentally. That is, better‐educated, wealthier parents are assumed to pass on privilege, creating environmentally driven inequality in educational opportunity and stifling what is called intergenerational educational mobility.
Genetics turns the interpretation of this correlation upside down. Socioeconomic status of parents is a measure of their educational and occupational outcomes, which are both substantially heritable. This means that the correlation between parents’ socioeconomic status and their children’s outcomes is actually about parent–offspring resemblance in education and occupation. Phrased as “parent-offspring resemblance,” it should come as no surprise that genetics largely mediates the correlation. Parent-offspring resemblance is an index of heritability, and heritability is an index of equal opportunity. So, parent-offspring resemblance for education and occupation indicates social mobility rather than social inertia.