Why are most people right-handed?
Question
Why is there not an equal split of right- and left-handed people across the planet? We seem to be living in a right-handed world.Mark, Enfield
Answer
Name: Guy, Kensington
Qualification: Studied developmental biology at university
Answer: It’s caused by testosterone imbalance during pregnancy which suppresses the left-hand side of the brain, making the right-side dominant, which controls the left-hand side of the body. Why the split is so large, I’ve no idea.
Name: Bob, Amersham
Qualification: I’m left-handed
Answer: About 10-15% of people in the world are left-handed and no one is 100% what causes it. The most commonly-4accepted theory involves very slight brain damage in utero. It means the other side of the brain takes over. Another theory is that it is genetic. It’s a combination of a number of factors.
(James O’Brien: I could have said it was a number of things. This doesn’t help us go definitive.)