Missing Heritability: Much More Than You Wanted to Know
The Story So Far The mid-20th century was the golden age of nurture. Psychoanalysis, behaviorism, and the spirit of the ‘60s convinced most experts that parents, peers, and propaganda were the most important causes of adult personality. Starting in the 1970s, the pendulum swung the other way. Twin studies shocked the world by demonstrating that most behavioral traits - including socially relevant traits like IQ - were substantially genetic. Typical estimates for adult IQ found it was about 60%