The genetics of Rain Man and Tennessee Williams

It's often speculated that the genes that predispose toward neuropsychiatric illness have positive effects. In my own research, I had an opportunity to test this idea in a high-functioning population, an entire class of undergraduates. My paper, co-authored with Ben Campbell, was published today in PLoS ONE (Princeton press release here).

We found that an interest in technical fields was predictive of a three-fold increase in the incidence in one's family of autism, which is strongly heritable. Conversely, an interest in humanities and social sciences was linked with three heritable disorders: bipolar syndrome, major depression, and substance abuse.

There are a few upshots here. First, it's been previously suggested that creativity and mental illness are linked. However, the creative populations studied are usually artists. When the study population is creative scientists, the linkage disappears. Our work suggests that it's the specific intellectual interest (arts), not creativity per se. Second, our work fits with the idea that mental illnesses represent extreme outcomes from a generation-to-generation shuffling of genes. Neuropsychiatric problems may be a price that we pay as a species for having a variety of intellectual interests.