Sizing up other people helped humans evolve their big brains

A bit of healthy competition is often regarded as a good way of helping people improve their performance. But it seems we may owe our big brains to our tendency to size each other up too. A team of scientists have found that judging other people's standing in a group appears to have played a key role in the evolution of human brain size over the past two million years. Making judgement about other people is a complex task that requires us to made decisions using a range of information. This'sizing up' process (stock picture) can help us decide whether to cooperate with others and played a key role in the evolution of our brains According to the team, the research could also have future implications in developing intelligent and autonomous machines.