Genes Matter
When identical twins are raised apart, you can disentangle nature and nurture for a given characteristic by simply measuring how similar the twins are…Ms. Segal emphasizes the uniformity of the results — the consistent power of genes, the limited influence of parenting…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.
More from Bryan Caplan in the Wall Street Journal. But see Matt Ridley: Genes determine IQ if you are rich. Environment is more important if you are poor.
Genes count for a lot more than our egalitarian ideals would typically like us to accept.
Genes matter — but, they are not destiny. Epigenetics also influences how genes express their characteristics.
A study of people who live extremely long lives found that most did not really have great health habits. They smoked, drank and lived lives like many people who died far younger.
The takeaway:
1) if you have great genes, you can live an unhealthy lifestyle.
2) an unhealthy lifestyle can nullify good genes
3) if you have bad genes, you better adopt a healthy lifestyle — but it may not help much.
While genes do play a huge role in determining the person you will ultimately become, I am a firm believer that how you were raised plays a huge role as well. If your genes make you ambitious with a high IQ, but you were brought up in an abusive household that did not encourage success, your life will have been very different than if you were brought up in a nurturing household that encouraged you to take every opportunity available.
It would be fascinating if somewhere a pair of identical twins married another pair of identical twins, and had offspring.
I’m sure this has happened somewhere at some point in history, but for the couples and their offspring to be studied might produce fascinating results.