Assortative Mating and Autism

https://slatestarcodex.com/2020/01/28/assortative-mating-and-autism/

Introduction

Assortative mating is when similar people marry and have children. Some people worry about assortative mating in Silicon Valley: highly analytical tech workers marry other highly analytical tech workers. If highly analytical tech workers have more autism risk genes than the general population, assortative mating could put their children at very high risk of autism. How concerned should this make us?

Methods / Sample Characteristics

I used the 2020 Slate Star Codex survey to investigate this question. It had 8,043 respondents selected for being interested in a highly analytical blog about topics like science and economics. The blog is associated with – and draws many of its readers from – the rationalist and effective altruist movements, both highly analytical. More than half of respondents worked in programming, engineering, math, or physics. 79% described themselves as atheist or agnostic. 65% described themselves as more interested in STEM than the humanities; only 15% said the opposite.

According to Kogan et al (2018), about 2.5% of US children are currently diagnosed with autism spectrum disorders. The difference between “autism” and “autism spectrum disorder” is complicated, shifts frequently, and is not very well-known to the public; this piece will treat them interchangeably from here on. There are no surveys of what percent of adults are diagnosed with autism; it is probably lower since most diagnoses happen during childhood and the condition was less appreciated in past decades. These numbers may be affected by parents’ education level and social class; one study shows that children in wealthy neighborhoods were up to twice as likely to get diagnosed as poorer children.