The Sports Gene by David Epstein

8 out of 10

Are sports stars born or made?  People all over the world are genetically similar; however, with tens of thousands of genes, small variations can lead to noticeably different phenotypes.  Athletic clustering occurs (Jamaican sprinters and Kenyan marathoners, for example). The breeding of humans is different from the breeding of domestic animals.  Still, the selective pressures are comparable (e.g. sled dogs are usually bred for speed, but there has been recent success selecting for endurance).  

Society seems to benefit from a certain % of warriors and a certain % of worriers.  Different people respond differently to different training regimens.  And it appears as though "work ethic" is inheritable.