9.5 Mate Choice in Humans

As a reminder, information on human mate choice is based on research conducted with large samples – using averages not individuals. This is an important concept to keep in mind. Regardless of the trait, there is always variation that exists outside the average. This is true for human mate preference, too.

In general, humans are serially monogamous. While we may have multiple romantic and sexual partners over our lifetime, these are usually one at a time. Of course, like other apes, this can be incredibly varied. In addition to same-sex or same-gendered partnering, there are times we may have multiple partners at once. Others may choose not to partner at all.

For the sake of this section, though, let’s proceed assuming serial monogamy is the norm.

Age and Wealth

Data suggest that, on average, men report preferring women who are 3-5 years younger. This changes slightly over the lifespan, and this gap can increase during the late 40s and early 50s. The exception may occur in early adulthood when men are more open to women slightly older than them. Alternatively, women tend to prefer men 3-4 years older, except during their 30s and 40s, where a temporary drive to partner with younger men occurs. Certainly, there are variations in these age gaps. And interestingly, in a sample of 12,656 Finnish adults, the reported age of actual partners did not track far from the age of the survey individuals. Yet, these trends remain relatively consistent across multiple cultures and social group sizes.

David Buss surveyed people from 37 different cultures, spanning a wide diversity of ethnicity, sex, religious practice, and economic status. He then categorized whether the data collected supported or contradicted some of the main hypotheses regarding mate preference. He found that support for the expectation that females value a mate capable of high earning potential (97%) and support the prediction that females also value ambition and drive to succeed (78%). He also found support that males seek attractiveness more than females (92%) and value chastity (62%). Keep in mind, in this study he is comparing the statistical outcomes.

There are evolutionary reasons for this, connected deeply to reproduction and offspring support. Younger women are often perceived to be more fertile. In modern societies like the United States, women become reproductively capable in their early to mid-teens. In smaller scale societies, like Hadzabe, this transition into reproductive adulthood – called menarche – occurs later, around 16 or 17 years of age. In evolutionary terms, younger men may still be establishing themselves as potential caregivers and hunters, while also still establishing themselves socially within the group. As such, these young men may not be viewed as sufficiently established to support the woman and any potential offspring.

This may also explain phenomenon like the midlife crisis, cougars, and the frequent relationships between young, attractive females and older, financially wealthy males. Of course, we should not assume this is always the case. Adaptive value is simply one way to explain behavior, after all.

Number of Partners

Interestingly, there are also consistent trends regarding the number of partners men and women desire. Women are more likely to prefer a smaller number of partners over a 30-year timespan, while men often desire twice or triple that amount. This difference also remains quite consistent across cultural areas like North America, Africa, and Southeast Asia.

The reason for these differences is closely connected to the costs of reproduction. While consciously considered or not, we know that every heterosexual interaction has the potential for pregnancy. Not counting the extensive investment after birth, women biologically invest heavily during pregnancy. If there are not enough resources, it may even be possible for the fetus and the woman to conflict over calorie consumption and overall well-being. Women must balance this potential cost, often preferencing the quality of her mates over the number.

In contrast, the reproductive investment for men is relatively small – that is, sperm are biologically inexpensive. And like many sexually reproducing species, it is likely that men evolved a reproductive strategy of quantity over quality. Unlike women, this leads to multiple partners.

Now, I want to emphasize that there is variation in these traits, too. This is not to say there aren’t women who seek variety or men who desire monogamy. Quite the contrary. Once a stable partnership is developed, both partners often invest emotionally and physically similar amounts of time and energy.

What about LGBTQ Preferences?

Honestly, we don’t know much. It has only been the past decade or so that evolutionarily framed research into non-heterosexual mating and relationships have occurred. We know some of these trends remain, but to what extent they are consistent across cultures is still unknown. Culturally, they are still quite varied, but are there underpinnings of the typical male and female mate choices?

While homosexual behavior, along with other forms of nonreproductive mating, may seem like an evolutionary paradox, nonheterosexual mating is present in other species. Evolution’s Rainbow: Diversity, Gender, and Sexuality in Nature and People is an excellent read into the varied forms of nonreproductive mating across species. Additionally, twin studies suggest that, while not fully predicted by genetics, there is mixed data to argue that a biological component for homosexual preferences does exist.

Shared Preferences

A survey across 33 cultures asked men and women about their most valued traits when seeking a mate (Buss, 1990). Selecting from a list of 18 potential traits, including those pertaining to age and wealth, something interesting emerged. The top four choices were exactly the same between men and women – in 33 cultures! And these top preferences were in no way connected to Buss’s initial hypotheses. These top, valued traits were:

1. Mutual Attraction/Love
2. Dependable Character
3. Emotional Stability and Maturity
4. Pleasing Disposition

This tells us that, beyond evolutionary sex differences, at the end of the day, getting along and feeling loved and supported remain most important to a strong relationship. It appears that one human universal is the desire to be loved.