I just sent off a saliva sample to 23andme to learn more about my genetic profile, and while I wait for the results, I've been continuing to look into the fascinating new discoveries about the influence of genes on personality traits. Over at Razib Khan's invaluable Gene Expression we find this table of heritability of particular personality traits (0.0 = no genetic influence; 1.0 = 100% determined by genes):
For comparison, your height is about 90% determined by your genetic makeup. By age 18, your genes determnine about 80% of your intelligence (it's hard to accurately test young children for intelligence, so the correlation increases as the test becomes more reliable and 'noise' decreases). Your genes also play a strong, if not determinative, role in your political orientation and personality structure. Of course, the headline of the post is misleading, I just gingered it up a bit to attract the attention of blank-slaters. As Khan aptly puts it: 'Biology may not be destiny, but it is definitely probability'.
One long-term trend we're seeing is the gradually increasing acceptance of findings such as these. There are still a few holdouts who, like global-warming skeptics, reject the findings out of hand, but their numbers are dwindling. I, for one, find it utterly fascinating. When I get my test results, I'll post anything interesting about them.