Why Are 90% of People Right-Handed, Whereas Other Primates Aren't?

Source: Google News - Health It is one of the strangest puzzles in human evolution: About 90% of people across every human culture favor their right hand—with no other primate species showing a population-level preference on this scale. Despite decades of research, the mystery of right-handedness has remained unsolved. Now, a new study suggests that the answer comes down to two features of human evolution—walking on two legs, and the dramatic expansion of the human brain.