Afterward, the researchers measured each participant’s self-esteem. Astonishingly, the men who were told their girlfriends scored at the top felt worse about themselves; their self-esteem took a hit. But if their girlfriends scored poorly, it actually boosted the men’s self-esteem. (Women’s self-esteem, meanwhile, didn’t change regardless of how their boyfriends scored.)
Good for the women. But for this to make the point in the text, it should need to hold for random pairings of men and women, not just those dating one another. The dating relationship weighs heavily on this result I’m guessing, as many men want to be providers etc. But do men lose self-esteem whenever any woman performs better? Quite possible this is true too, but why not find that study?

