As any left-handed person who’s ever struggled with a pair of scissors can attest, the physical world is largely built for righties, who comprise up to 90 percent of the population. But that imbalance also affects lefties in more subtle and profound ways than just unwieldy office supplies.
Daniel Casasanto, a psychologist at the University of Chicago, studies the ways in which the world is mentally biased toward the right. His research has shown that politicians, for example, tend to use their non-dominant hand for negative gestures, and parents in recent decades have shown a preference for baby names typed on the right side of the keyboard. Now, Casasanto is studying how handedness affects “approach motivation”—how we approach or avoid physical and social situations in the world around us.
Casasanto recently discussed his work at the February 2016 meeting of the American Association for the Advancement of Science in Washington, D.C. Afterwards, I spoke to him about society’s rightie bias, and what that means for lefties. Below is an edited and condensed version of our conversation.
Natalie Jacewicz: So what determines right- or left-handedness?
Daniel Casasanto: What determines handedness is still a mystery. There’s a large genetic component. But in identical twins, if one twin is left-handed, the other twin is left-handed only about 70 percent of the time. So there’s likely to be a fairly significant experiential component.