For centuries scientists have tried to explain why only 10 percent of the population is left-handed. Lefties have been the subject of jokes, ridicule and admiration and have been cast as wacky, offbeat, and out-of-the box personality types.
New research suggests there may be some truth regarding the unique orientation of southpaws.
According to scientists, there are areas in the brain devoted to our arms, legs, and various parts of our bodies.
The distribution of these sites within our brain is known as “body maps” and there are some significant differences in these maps between left- and right-handed people.
For example, in left-handed people, there is an equal amount of brain area devoted to the left and right arms in both hemispheres. However, for right-handed people, there is more cortical area associated with the right arm than the left.
Psychologists from the University of Virginia, Purdue University, and The College of William and Mary assessed if the difference in body maps would lead to differences in how we perceive the length of our arms.
The results, reported in Psychological Science, reveal some differences in the way left- and right-handed people perceive their arms. Left-handed volunteers judged both of their arms to be the same length, but right-handed participants underestimated the length of their left arm—they consistently perceived their right arms as being longer.
In addition, right-handed volunteers thought their right hands were larger than their left, when in fact, they were both the same size. When guessing how far they could reach with their arms, left-handed volunteers estimated they could reach equally far with both arms while right-handed volunteers predicted they could reach farther with their right arm.
These findings suggest that body maps in our brain may influence how we perceive our physical bodies—for example, if there is a lot of brain area associated with our right arm, we will view it being as longer compared to our left arm.