Soon after Jay Z welcomed his first child, Blue Ivy Carter, last year, a poem the rapper had reportedly dedicated to his new baby girl zipped around the Internet. “Before I got in the game, made a change, and got rich / I didn’t think hard about using the word B----,” it opened. “I rapped, I flipped it, I sold it, I lived it / now with my daughter in this world / I curse those that give it.” The poem turned out to be a hoax, but a spate of recent research backs the idea that close relationships with women can dramatically sway men’s attitudes and behavior, at home and at work, for better and for worse:

Male CEOs typically pay their employees less and themselves more after having sons, but this trend doesn’t hold with daughters. In fact, male CEOs with firstborn daughters actually pay their employees more, giving female employees the biggest raises [1].

Men who have daughters also grow less attached to traditional gender roles: they become less likely to agree with the statement that “a woman’s place is in the home,” for instance, and more likely to agree that men should wash dishes and do other chores [2].

Having a sister, however, has the opposite effect, making men more supportive of traditional gender roles, more conservative politically, and less likely to perform housework [3].