Why do women prefer more masculine men during the fertile phase of their menstrual cycle? Why are men more distressed by a partner’s sexual infidelity than their emotional infidelity? And why do female dating profiles advertise beauty, while male dating profiles boast about wealth?
The relatively new field of evolutionary psychology has answered all of these questions, and more. By applying evolutionary theory to the study of human mating behavior, psychologists have revolutionized our understanding of attraction, jealousy, lust, and love.
But surely there’s one question that evolutionary psychology can never answer: Why does anyone stay single?
If natural selection favors individuals who are best able to survive and reproduce, what possible benefit might there be to bowing out of the mating market? For countless generations, our ancestors have successfully reproduced. If evolution has shaped human desire, the prospect of life as a singleton should be as terrifying and impossible as holding your breath for 20 minutes. And yet, for many, remaining single is a conscious lifestyle choice. Why?
76 Reasons to Stay Single
It’s a question that occurred to Menelaos Apostelou, an evolutionary psychologist at the University of Nicosia in Cyprus. To answer it, he gathered together 120 men and women for an in-depth discussion of the reasons why people might stay single. After discarding very similar answers, he had a list of 76 distinct reasons.
Next, Apostelou sent a team of research assistants onto the streets of Cyprus to ask the public how likely each of the 76 reasons might be to cause them to stay single. Some reasons tended to go with others: If someone said they were worried that nobody wanted to be with them, they were also likely to say that they couldn’t find the right person. If they said they didn’t want to lose their freedom, there was a good chance they would also say they like to have their own space. Through these surveys, Apostelou found that the 76 reasons clustered into 15 groups, which in turn clustered into three super-groups, or broad and distinct reasons people choose to stay single:
Super-group 1: freedom of choice included reasons that seemed to be about wanting to flirt, be free, not commit, avoid conflict and constraints, and feeling that one is already doing well without a partner, as well as having different priorities and simply enjoying being alone.
Super-group 2: constraints included reasons relating to sexual dysfunction and other factors that might hold a person back from starting a relationship, such as a health problem, being older, or having children from a previous relationship.
Super-group 3: difficulties with relationships included reasons to do with bad experiences in previous romantic encounters, a lack of trust in others, a fear of change, an unwillingness to compromise, difficulties starting a relationship, and a feeling that one would not be better off with a partner.
Although most people will identify with reasons in each of the three super-groups, people who chose a reason from within one super-group were more likely to choose other reasons from within that same group. This suggests that, at least among Apostelou’s Greek-Cypriot research volunteers, there are three broad reasons why people choose to stay single—because they like to be free to set other priorities, because they feel cannot successfully compete for a partner, and because they find relationships difficult.
An Evolutionary Account
So far, so good. But what does this have to do with evolution? Apostelou’s argument goes like this:
Evolution has selected for ways of thinking and behaving that enhance our reproductive success, or the number of offspring we produce. So we shouldn’t be surprised that humans are motivated to pursue relationships. However, it should be surprising if humans pursued relationships indiscriminately, regardless of the costs.
For example, men with a greater earning potential tend to be more attractive to women. This means it makes less sense for a man to settle down with his high-school sweetheart at 18 than to focus on his education and developing his career, so that he can be more competitive for mates later (although a man with fewer opportunities for advancement might do better to marry young). By the same token, a woman who decides to marry the first man she dates might be making a bad move, but after dating more men, she will be better placed to make an informed decision about the best partner for her.
In both cases, these people would be staying single to exercise freedom of choice, applying reasons from Apostelou’s first super-group, but in a manner that is consistent with evolutionary theory. Staying single can allow you to pursue short-term flings, gain experience evaluating potential matches, and develop yourself to better attract desired partners later.
Now imagine another set of possibilities: If you are ill, it might not be the best time to settle down. You may have a better chance of finding an attractive partner if you wait until your health improves. If you have young kids with an ex-partner, this might make you less attractive to a new partner. In this case, you might decide to invest your energy and resources in your children, instead of a romantic relationship. If you are older, or infertile, you may choose to invest in the children of relatives or in your own grandchildren.
All of these constraints could lead you to reason that it makes more sense to stay single, at least for the time being—and again, your behavior would make sense in light of evolutionary theory.
We’ve seen how reasons for staying single that fit within Apostelou’s first and second super-groups are not incompatible with natural selection. But what about the third super-group — difficulties with relationships? Here, Apostelou takes a different tack. He reasons that navigating romantic relationships is a modern phenomenon. For much of human history, men may have secured partnerships with women by simply out-competing other men in physical combat, gorilla-style. Meanwhile, women may have had less choice in their partners, with a loose system of marriages arranged by parents as the norm. Apostelou says:
"In ancestral human environments, individuals would get mates from their parents or by fighting other men, rather than by addressing opposite-sex partners directly. Thus, selection forces had not enough time to augment the capacity of individuals to approach and persuade other individuals to establish an intimate relationship with them."
In other words, those who stay single because they have trouble flirting, because they are too shy, or because they believe nobody wants to be with them are not operating a shrewd, long-term mating strategy. They are not unconsciously weighing the costs and benefits of settling down now rather than later. Instead, they are suffering the consequences of our species’ rapid development from hunter-gatherers to citizens of modern industrial economies in the (relative) blink of an eye.
In Apostelou’s view, natural selection "wants" these people to find a partner, but human circumstances have changed so quickly that evolution has yet to come up with a solution to these dating woes.
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Apostolou, M. (2017). Why people stay single: An evolutionary perspective. Personality and Individual Differences, 111, 263-271.