For seventy years ecologists have debated to what extent competition affects the composition of ecological communities. At one extreme, species have been proposed to assemble independently of each other, while at the other extreme, competition and other interspecific interactions have been...

We look at gender differences in preferences for altruism, risk and competition in math and word search among adolescents in Sweden. We find that girls are more altruistic and less risk taking than boys. We find no gender gap in performance change when comparing performance under non-competition...