LONDON: Around 90 percent of humans prefer to use their right hand for most skilled tasks, which researchers have been trying to unravel for decades. A study suggests the explanation may stem from actions that require us to use both hands at the same time.
The study was from researchers of the University of Aberdeen in the UK.
Gavin Buckingham, University of Western Ontario in Canada, and his supervisor David Carey asked left and right handers to reach first towards a pair of target with both hands at the same time and, immediately afterwards, towards a new single target with only their closest hand, the journal Elsevier's Cortex reports.
Just before they began, subjects were given a short vibratory pulse on one of their hands, giving them a clue about where the new target would appear, and hence which hand should perform this second portion of the reach, according to an Aberdeen University statement.
On a small proportion of trials, the pulse was given to the wrong hand, which meant that subjects had to restrain the reach with this incorrectly-cued hand in order to make the reach with the correct hand.
The right-hander had far greater trouble dealing with this incorrect cue when it was given to their right hands, making more mistakes and taking longer to successfully inhibit the reaches.
The left-handed subjects showed no such asymmetries, suggesting that they are less inherently biased to select one hand over the other.
"Many left-handed people have 'right-handed' brains, which weakens the typical bias towards choosing their dominant left hand," Carey says.