Leave It to Science: Should We Have Sex on the First Date?

Leave It to Science: Should We Have Sex on the First Date?

Imagine: you’re on the perfect first date with someone. He or she is exceptionally beautiful, says all the right things, and shares your taste in music. After the two of you finish the second bottle of wine, the waiter kindly tells you that the restaurant is closing. Your date smiles and says: “would you like to come home with me?” From a scientific point of view; what is the correct answer?


Surprise, surprise : men are more likely than women to engage in short-term mating – casual sex. And we have evolutionary biology to blame for that. Although both sexes claim to enjoy sex ‘with no strings attached’, only she was at risk of becoming pregnant afterwards. As a result, men and women have adapted different mating strategies.

It’s basic economics, really. The decision to engage in casual sex depends on the costs it entails. For men, the costs are low. Worst case scenario, they catch a sexually transmitted disease. For women however, there is much more at stake. One fling can ruin her reputation, and if she becomes pregnant, sentence her to a lifetime of motherhood. As a result of these differences, men and women apply different sexual strategies.

Hi. Would you have sex with me?
The idea that men and women apply different strategies to mating, is supported by a number of scientific studies. In one experiment, when men were asked how many sex partners they would ideally like, they reported that they would like 18 in their lifetime. Women on the other hand said to be satisfied with 4,5 partners. Another well-known behavioural study, which was first conducted in 1989, had a similar outcome. During the experiment, both male and female researchers approached total strangers on a college campus, and said “Hi, I’ve been noticing you around campus, and I find you very attractive.” Then they asked one of three questions: Would you go out on a date with me? Would you go back to my apartment with me? Would you have sex with me? The experimenters recorded the percentage who agreed to each request. Of the women approached by the male experimenters, 50% agreed to go out on a date with him; 6% agreed to go back to his apartment; and 0% agreed to have sex. Of the men approached by the female experimenters, 50% agreed to go out on a date, similar to the women’s responses. However, 69% agreed to go back to her apartment. And 75% agreed to have sex with her.

 “Then they asked one of three questions: Would you go out on a date with me? Would you go back to my apartment with me? Would you have sex with me?”

On the back burner
Both studies lead to a similar assumption: men have more sex partners than women do. But isn’t this mathematically impossible? Every time a man has sex with a woman whom he has not previously had sex with, a woman is simultaneously having sex with a man who she has never had sex with. The logical answer would be that women, although they might not prefer it over finding a long-term partner, engage in short-term sexual relationships as well.

According to evolutionary psychologist David Buss, women adapted this strategy so they could get men of high status, dominance, and genetic quality. However, there’s one benefit that is even more important: mate insurance. “Ancestral women who failed to have mate insurance, a backup replacement in the event that something happened to her regular partner, would have suffered greatly compared to women who cultivated potential replacements,” Buss says. “Modern women have inherited the desires of their ancestral mothers for replacement mates. In the words of one woman in our study, “Men are like soup — you always want to have one on the back burner.”

“Men are like soup — you always want to have one on the back burner”


So short-term mating can improve the quality of your offspring, but will it also improve your chances of finding your bride- or groom-to-be? From the field of psychology the answer is clear: if you’re looking for a long-term thing, you’d better keep your pants on.

Professor Anne Campbell looked at whether women have adapted to casual sex by examining their feelings following a one-night stand. Did they enjoy the experience, or did they only feel regret afterwards? To test this, a total of 1743 men and women who had had a one-night stand were asked to rate both their positive and negative feelings the following morning, in an internet survey. Not surprisingly, most of the men reported they felt “sexually satisfied and content.” They were more likely than women to secretly want their friends to hear about the one-night stand, and “felt successful because their partner was desirable to others.” For the women, on the other hand, the morning after wasn’t as fun as they probably had hoped. Almost half of the female participants regretted the hook-up, stating that it “made them feel used,” and “that it wasn’t sexually satisfying.”

Not designed for casual sex
According to Dr. Campbell, the study shows that women –from an evolutionary perspective- are not designed for short-term relationships, thereby dismissing the claim evolutionary biologist have made. “Recently, biologists have suggested that females could benefit from mating with many men – it would increase the genetic diversity of their children, and, if a high quality man would not stay with them forever, they might at least get his excellent genes for their child. But if that were the case, why then do women not enjoy casual sex as much as men do?”

It’s an interesting question. According to another study published in the Journal of Family Psychology, however, it’s not just the women who should refrain from having first date-sex. Researchers found that couples who had sex the earliest — such as after the first date or within the first month of dating — had the worst relationship outcomes.

“Why then do women not enjoy casual sex as much as men do?”

Hurray for chastity
Research psychologist Dean Busby and his colleagues examined 2,035 heterosexual participants, who had an average age of 36. All of them were in their first marriages. The subjects were asked when they first had sexual relations with their current spouse; how well they could express empathy and understanding toward their partners; how satisfied they were with their sex life and how often they thought their relationship was in trouble. To make sure religion would not affect the outcome of the study, the researchers controlled for the influence of religious involvement in their analysis.

As it turned out, those who waited reported to have a more stable relationship and a better sex life. “Curiously, almost 40 percent of couples are essentially sexual within the first or second time they go out, but we suspect that if you asked these same couples at this early stage of their relationship – ‘Do you trust this person to watch your pet for a weekend many could not answer this in the affirmative’ – meaning they are more comfortable letting people into their bodies than they are with them watching their cat,” Busby says.


Although mathematicians and psychologists do not often agree, they offer the same advice when it comes to sex: don’t give it up on the first date. According to a numerical model they developed, the good guys were willing to date for a longer time before having sex, while the rotten apples were reluctant to stick around.

The model is based on the idea that a woman will get a positive payoff from mating only if the man is a ‘‘good’’ male, with respect to his genetic quality, or ability or intention to provide paternal care. If she decides to sleep with a ‘‘bad’’ male, she will get a negative payoff from mating with him. In addition, a ‘‘good’’ male is willing to court for longer than a ‘‘bad’’ male; in this way the duration of a male’s courtship signals his type, and acts as a costly handicap.

“The good guys were willing to date for a longer time before having sex”

Die a virgin
“Long courtship is a price paid for increasing the chance that mating, if it occurs, will be a harmonious match which benefits both sexes,” says professor Robert Seymour, leading author of the study. His colleague, Dr Peter Sozou, explains: “The strategic problem a female faces is how to screen out bad males, and this is where long courtship comes into play. A male is assumed to always want to mate with a female, but a good male is more willing to pay the cost of a long courtship to claim the prize of mating. So the female’s strategy is a compromise, a trade-off.” What the equations do not reveal is how long men should be kept waiting, in light of the fact that not even good guys will necessarily wait forever. Deciding on the length of courtship is thus a matter of judgement – which isn’t much help for women of a certain age. Also, a woman cannot eliminate the risk completely unless she decides never to mate. Apparently, there’s only one way to avoid the chances of picking a dud guy altogether: die a virgin.

So, back to your perfect first date. He or she is still waiting for your answer. “Are you coming with?” In the end, it all depends on what you’re looking for. If you just want to have some fun, don’t hesitate, go. If you’re aiming for a long-term thing, however, kindly decline and go home. Alone. You’ll thank yourself later.

Campbell, A. (2008). The Morning after the Night Before Human Nature, 19 (2), 157-173 DOI: 10.1007/s12110-008-9036-2

Anouk Vleugels

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