Bend Sinister

From this month's Atlantic:


"Unless you're trying to fill out your bullpen for a post-season run, the evolutionary usefulness of left-handedness may seem a little puzzling. But it turns out that southpaws may remain in the gene pool because they're good to have around in a fight. A study by two French academics tracked the prevalence of left-handedness across a variety of traditional societies, and found that the more violent ones tended to have a higher percentage of lefties. Among the Dioula people of Burkina Faso, for instance, the homicide rate is just 0.013 murders per thousand inhabitants per year, and left-handers make up only 3.4 percent of the population. In contrast, the more warlike Yanomamo of the Venezuelan rain forest have a homicide rate of four per thousand per year, and southpaws compose roughly 23 percent of their population. What's advantageous in baseball, it turns out, may also be advantageous in a jungle knife fight."

"Handedness, Homicide and Negative Frequency-Dependent Selection," Charlotte Fourie and Michel Raymond, Institute of Evolutionary Sciences, University Montpellier II