09/30/2025

Left-handedness and the Brain

New research reflects differences in motor and emotion networks

Approximately 10.6 percent of people are left-handed. It is still not well understood why some people prefer to write, draw and perform other activities with their left hand, while most people prefer to use their right hand for these things. Recent research about left-handedness has focused on brain differences between left-handers and right-handers.

This makes a lot of sense: Left-handedness is not caused by the hands themselves, but by the differences in brain organization—but which?

Somewhat surprisingly, not much came out of research focused on the size of different brain areas. For example, a large-scale neuro-imaging study found no statistically significant differences in the surface area of different brain regions between left- and right-handers Only when very liberal statistical thresholds were used, a difference was found in the pre-central sulcus, a brain area relevant for motor behavior. These findings suggest that it may not solely be differences in the size of brain areas that make left-handers' brains different from right-handers' brains.

Please select this link to read the complete article from Psychology Today.