The Minnesota researchers tracked down every pair they could find—and measured traits related to almost every aspect of life: health, cognition, personality, happiness, career, creativity, politics, religion, sex and much more. The Minnesota study reveals genetic effects on virtually every trait. The breakdown between nature, nurture and everything else varies from trait to trait. But Ms. Segal emphasizes the uniformity of the results—the consistent power of genes, the limited influence of parenting.
Some findings go down easy: As most would expect, identical twins raised apart have virtually identical heights as adults. Some findings seem obvious after the fact: Genes, but not upbringing, have a pretty big effect on personality traits like ambition, optimism, aggression and traditionalism. Other findings perennially cause outrage: The IQs of separated identical twins are almost as similar as their heights. Critics of intelligence research often hail the importance of practice rathe…
Some findings go down easy: As most would expect, identical twins raised apart have virtually identical heights as adults. Some findings seem obvious after the fact: Genes, but not upbringing, have a pretty big effect on personality traits like ambition, optimism, aggression and traditionalism. Other findings perennially cause outrage: The IQs of separated identical twins are almost as similar as their heights. Critics of intelligence research often hail the importance of practice rathe…