Difficulty: Challenger (Level 2)
Look around, and you will probably notice that most people write using their right hand.
Only about 10 per cent of people are left-handed. This includes famous historical figures like Napoleon Bonaparte and Leonardo da Vinci. This is just one of the many rare abilities that some people have (see graphic).
Scientists at the University of Oxford and the University of Reading believe they have found one reason most people use their right hand. Their paper was published by PLOS Biology.
The answer comes down to how human brains developed and expanded. It is also related to how we walk on two legs.
This is different from other primates, where left-handedness is more common.
“It is probably tied to some of the key features that make us human, especially walking upright and the evolution of larger brains,” Thomas Puschel said. He is a professor of evolutionary anthropology at the University of Oxford.
The team noted that it is very unusual that almost all humans use their right hand.
“About 90 per cent of people across every human culture favour their right hand,” the paper said.
The researchers called this a mystery. No other primate species, like apes or monkeys, shares such a common habit.
Research has shown that we choose our dominant hand before we are born. This is when the spine is still growing.
In the 13th week of pregnancy, an unborn baby already prefers to suck either the right or the left thumb.
