Selection against variants in the genome associated with educational attainment

In plain English, people who have a genetic profile associated with attaining more years of education put off having children until later in life, and have fewer children, so this genetic profile has been declining in the population.

http://www.pnas.org/content/114/5/e727


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We show that an educational attainment polygenic score, POLYEDU, constructed from results of a recent study is associated with delayed reproduction (P < 10−100) and fewer children overall. The effect is stronger for women and remains highly significant after adjusting for educational attainment. Based on 129,808 Icelanders born between 1910 and 1990, we find that the average POLYEDU has been declining at a rate of ∼0.010 standard units per decade, which is substantial on an evolutionary timescale. Most importantly, because POLYEDU only captures a fraction of the overall underlying genetic component the latter could be declining at a rate that is two to three times faster.

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From the results presented here it is clear that there has been a slow but steady decline in the frequency of certain variants in the Icelandic gene pool that are associated with educational attainment. It is also clear that education attained does not explain all of the effect. Hence, it seems that the effect is caused by a certain capacity to acquire education that is not always realized. We postulate that, in addition to being correlated with cognitive ability (32, 33), POLYEDU is capturing a portion of the propensity to long-term planning and delayed gratification.

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