We study same-sex role model effects of teachers with a meta-analysis and our own study of three million students in 90 countries. Both approaches show that role model effects on performance are, on average, small: 0.030 SD in the meta-analysis and 0.015 SD in our multi-country study. Going...

The immense literature on discrimination treats outcomes as relative: One group suffers compared to another. But does a difference arise because agents discriminate against others--are exophobic--or because they favor their own kind--are endophilic? This difference matters, as the relative...