Right-handed have a 'right' bias

CHARLOTTESVILLE, Va., Nov. 6 (UPI) -- In left-handed people equal parts of the brain are devoted to each arm but in the right-handed more of the brain is devoted to the right, U.S. researchers say.

University of Virginia in Charlottesville psychologists Sally Linkenauger, Jonathan Bakdash and Dennis Proffitt found right-handed people have more cortical area in the brain devoted to the right arm than to the left one. This may affect how they "see" their right hand.

In experiments, left-handed volunteers judged both of their arms to be the same length but right-handed participants underestimated the length of their left arm and 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.

The study, published in Psychological Science, also involved researchers Jessica Witt of Purdue University in West Lafayette, Ind., and Jeanine Stefanucci of The College of William and Mary in Williamsburg, Va.