Evolutionary psychologist Satoshi Kanozawa has written that "men in every single culture prefer to mate with younger women, and women prefer to mate with older men." And Nick Neave, also an evolutionary psychologist, wrote a few years ago that women are driven by their "primeval urge to hang onto a male provider," even if they live in modern societies and can financially support themselves. Devotees of evolutionary psychology — a discipline that seeks to explain our modern brains by looking to our prehistoric ancestors — have long argued that who we want to date, sleep with, and marry are determined by the basic needs that preoccupied our early human forebears. But a new study has cast some doubt on this, showing that the level of gender equality in our society can influence the kind of man or woman we want to be with.

Psychologists Marcel Zentner and Klaudia Mitura surveyed over 3,000 people from 10 countries (South Korea, Mexico, Turkey, Italy, Poland, Portugal, Finland, the Philippines, Germany, and the US) about what they were looking for in a partner. Specifically, they asked participants to rate the importance they placed on the following traits: high earning potential, ambition/industriousness, good looks, chastity, high social status, education, intelligence, domestic skills, and being the right age. Then they looked at gender equality in the 10 countries, as measured by factors like women's literacy and education, their representation in positions of power and professional jobs, and their average income relative to men's.

What they found was that the more equal men and women were in a country, the less important they tended to find the traditionally masculine or feminine traits that evolutionary psychologists say everyone prizes. So men were less likely to care about chastity or domestic skills, women were less likely to care about earning potential, and both were less likely to care about a partner's age. The study authors also looked at gender equality and mate preferences collected in a previous, larger study of 37 countries, and found that in this larger group, more equality also meant less emphasis on purportedly evolutionary ideals.

The authors didn't study why equality would change what people want in a partner, but they do note that previous research shows that socially-enforced gender roles "shape gender differences in ideas of a good mate, which are passed on from one generation to another" — if young men in a culture see that all cooking is done by women, they may start to want a wife who can cook, and then teach their sons to look for the same. They also note that even the most equal countries in their sample, like Finland and the US, were far from reaching true equality. So this cultural shaping of preferences could well still be happening even there. And they point out that if people's preferences in a mate change from country to country, they probably aren't wired into our brains.

Evolutionary psychologists' arguments about what men and women are looking for can have real social effects, lending scientific legitimacy to the claim that older women simply can't be attractive. This in turn can fuel the demand for cosmetic procedures and various anti-aging products — Kanazawa makes this connection explicit, writing that, "through face-lifts, wigs, liposuction, surgical breast augmentation, hair dye, and color contact lenses, any woman — regardless of age — can have many of the key features that define the ideal female beauty." But if preferences for things like women's youth and men's money really do change with cultural norms, then maybe as society gets more equal we can all save money on hair dye.