Human beings have been predominantly right-handed for more than 500,000 years, according to new research findings. Yet 10 to 12 percent of people prefer using their left hand — and scientists continue to probe the differences between that group and the right-handed majority, often with surprising results. Here, a look at five ways lefties are different than righties:
1. They're more affected by fear
In one recent experiment, lefties who watched an eight-minute clip from the film Silence of the Lambs exhibited more symptoms of post-traumatic stress disorder than did their right-handed counterparts. That may be because the right side of the brain, which is dominant in lefties, is more involved in the fear response, according to Dr. Carolyn Choudhary of Queen Margaret University in Edinburgh, as quoted in The Telegraph. But more research is needed, Choudhary warns.
2. They're angrier
Left-handed and ambidextrous people are more susceptible to negative emotions, including anger. A small study published last year in the Journal of Nervous and Mental Disease found that the brains of lefties process emotions differently than those of righties, with more communication between the brain's two halves. As a result, the areas that produce negative emotions experience greater activity, according to the Daily Mail. Then again, maybe lefties are just "more angry because the world is designed for the right-handed majority," says John Cloud in TIME.
3. They're more inhibited
That emotional wiring also may explain why righties tend to charge ahead, while lefties "tend to dither," according to behavioral psychologist Lynn Wright, as quoted in NewScientist. A study performed by Wright at Abertay University in Scotland found that lefties were more restrained and more worried about making mistakes.
4. They associate "left" with good
Most people tend to have positive associations with the concept of "right" and bad associations with "left." Lefties are the opposite. In a recent study, Stanford researcher Daniel Casasanto asked participants to draw a zebra in a box that best represented good things, while depicting a panda in a box that would befit the bad. Right-handed people tended to position the zebra on the right side of a box, while lefties put it on the left. That shows that left-handed people "implicitly" believe "good stuff is on the left and bad stuff is on the right," Casasanto says, as quoted by the Stanford Report, despite so many signals from language and culture "telling them the exact opposite."
5. They may have an advantage in politics
Casasanto's conclusions could actually favor left-handed politicians, at least in televised events like debates, says Jocelyn Rousey in Mediaite. Casasanto found that politicians tend to accompany statements they see as positive by gesturing with their dominant hands. When a rightie uses his dominant hand to give a thumbs-up, television viewers — who see the image flipped — see him gesture on the left side of their screen. The left-handed, meanwhile, "appear to be putting things in a much more positive light for the 90 percent of viewers who are right-handed."