Monday, December 23, 2013

Assortative Mating

Gregory Cochran and Henry Harpending have an interesting post at their blog West Hunter on human assortative mating. This means the tendency for like to marry like (i.e. mate with & produce offspring) on some trait. The heritable traits people care about tend to be those which reproduce a pleasant, technologically-advanced civilization: attributes such as an IQ above 105, openness, agreeableness and conscientiousness.

The authors have a blog post on this topic from a few years back and a new PDF in draft (which uses some technical language but is not too technical in content). The results are that if the right and left population-segments of the bell curve (for that heritable trait) mate assortatively - largely amongst themselves - then a caste system (high-merit vs. low-merit) emerges within one generation and then consolidates. They speculate that with mass university-level education, we're already doing this experiment for the trait of intelligence.

The result? Perhaps a hollowed out middle in our society.