Here’s one of the surest routes for men to think of women as equals: Have a daughter.

In Silicon Valley, the venture capitalists who invest in tech start-ups are significantly more likely to hire a female investing partner if the hiring partners have daughters, according to a new study by researchers at Harvard. Having mixed-gender teams in turn improved venture capital firms’ financial performance — providing rare quantifiable evidence of the business benefits of diversity.

The influence of daughters is consistent with previous research that shows that fathers of daughters support more egalitarian gender roles, and that male lawmakers, judges and corporate executives with daughters are more likely to support gender equity and policies that benefit women.

Even men who play traditional gender roles in their personal lives tend to want their daughters to be independent and high-achieving, research has found. Having daughters seems to make them more aware of sexism or expose them to challenges different from their own. Ivanka Trump, for example, has done this in at least one way, by encouraging her father to include a paid parental leave policy in his new White House budget.

“If I’m an old white male, I perhaps wouldn’t go out of my way to associate with young females,” said Maya Sen, a professor at the Harvard Kennedy School of Government. “But if I have a daughter, I do come into contact with her and her friends, so it breaks the flocking with like-minded people.” Ms. Sen was not involved in the new study, but found in a previous study that judges, particularly Republican ones, were more likely to vote in favor of women on issues like sex discrimination if they had daughters.