Frequency-dependent selection and left-handed people
According to some authors, the frequency of left-handed people in the population is regulated by frequency-dependent selection. Left-handed people are at an advantage in battles and fist-fights (and also in a number of sports) as their opponents are not prepared for their fighting methods because there are fewer of them in the population than right-handed people. Comparative studies on a large number of traditional human populations have actually shown that that the frequency of left-handed people (3–27%) is directly dependent on the amount of violence in the population (specifically, the number of violent deaths).