Around 90 per cent of people are right-handed. This is because of human evolution. When we first walked on two legs, our hands did more things. Our large brain thought of many things to do with our hands. If most people used the same hand, it was easier to do things like hunt, cook, and use tools.

Scientists wondered why humans, but not monkeys, are largely right-handed. Researchers compared human behaviour with monkey behaviour. A researcher said that by looking at monkeys, we can understand why many of us use our right hands. We started using our right hands millions of years ago.