Handedness and the 2016 U.S. Primaries: consistent handedness predicts support for Donald Trump among republicans, but gender predicts support for Hillary Clinton among democrats.

A growing number of studies demonstrate that consistent handers, people who use their dominant hand for all or most manual tasks, are less cognitively flexible than inconsistent handers, people who use their non-dominant hands at least some of the time. A recent hypothesis suggests that differences in handedness emerged evolutionarily because populations benefited from a balance between cognitively rigid and cognitively flexible people. One expectation is that cognitively rigid consistent handers would support more authoritarian policies or candidates. To test this idea, we looked at handedness, gender, and political affiliation as predictors of support for Donald Trump, a candidate whose supporters self-report being more authoritarian, in the 2016 primary. Our data show that in the Republican Primary, consistent handers report more support than inconsistent for Donald Trump. When authoritarianism was added as a covariate, the handedness effect disappeared. Further analyses showed that authoritarianism mediates the relationship between handedness and support for Donald Trump. In the Democratic Primary, there was a main effect of gender. Women reported more support than men for Hillary Clinton.