http://www.psychologytoday.com/articles/199909/career-your-dreams-career-your-genes This should really not be surprising. Genetics have an effect on abilities and interests. I think it could be possible that different groups of people are, through natural selection, evolving to fit into different types of jobs, different niches within the economic system. In every society, these different groups of people will come to exist. I suggest that these different groups of people are less likely to intermarry outside their own group, so as to preserve the genetic specialisation. This genetic isolation could be reinforced by social phenoma: class, caste, income level, education, neighborhood, and, for more diverse societies (Brazil is a good example), race and ethnicity. There is mixing between all the different groups, yet each group remains distinct, and tends to do certain types of jobs.
