Key Study: Evolution of Gender Differences in Sexual Behaviour (Clark and Hatfield, 1989)

Travis DixonBiological Psychology, Key Studies, Studies and Theories

Why are men more promiscuous than women? Clark and Hatfield's study from Florida State University might just give us an answer.

If a man sleeps with lots of women he’s a “stud” but if a woman does it she’s a “slut.” By why does this societal double-standard exist and are men really more promiscuous than women? Clark and Hatfield’s classic study might be able to give us some answers to these questions.

Background Information

The perception exists in society that men are interested in sleeping around and “sewing their wild oats” while women are more interested in meeting “Mr. Right” and settling down. In other words, it is a common perception that men are more willing to have sex with many different partners and even with complete strangers, than are women.

Latin American Girl Flirting With German Male Student At Classro

This classic study shows men are far more willing to have sex with a stranger than women are. As psychologists, we have to ask the question, “why?”

But does the research support this idea that men are more promiscuous than women? As you will see, it does. But is this the fault of men, or are they simply behaving the way they have evolved to?


The studies conducted by conducted by Clark and Hatfield in (1978 and 1982) posed this question: “How receptive are men versus women to sexual invitations?”

In both experiments, five college women and four college men from an experimental social psychology class acted as confederates. They were instructed to stand in an area of the college campus and approach members of the opposite gender. They were instructed to only approach those that they found attractive and would be willing to actually sleep with (in any other scenario, presumably). When the confederates spotted someone they liked they said: “I have been noticing you around campus. I found you to be very attractive.” They then asked one of three different questions:

  1. “Would you go out with me tonight?”
  2. “Would you come over to my apartment tonight?”
  3. “Would you go to bed with me tonight?

In total, 48 men and 48 women were asked these questions from a member of the opposite gender (i.e. 16 each question). The results of both studies were very similar, as you can see in the images below. 

Results from Two Experiments

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As you can see, both sexes responded similarly to a request for a date. However, when it came to going to an apartment or going to bed (i.e. having sex), the males were far more willing to agree (75%) than the women (0%).

Screen Shot 2019-02-21 at 11.18.49

This second field experiment four years later got remarkably similar results to the previous study, further strengthening the evidence for the existence of distinctly different gender-related sexual behaviours.

What we see from the above results is that males are far more willing to have sex with a stranger than females, despite the fact that both genders were about the same in their willingness to go on a date. What’s even more surprising, and I’m sorry guys but it doesn’t look good for us, is that men were more willing to have sex with a stranger than they were willing to go on a date.

Evolutionary Explanation

Differences in sexual behaviour between men and women can be explained by looking at the different roles in child bearing and raising. Remember that an evolutionary explanation of behaviour is one that shows how the behaviour can increase the chances of an individual passing on their genes and/or having healthy children. In this case, the behaviour we are explaining is the promiscuity – or the difference in men and women’s readiness to sleep with a stranger.

From an evolutionary perspective, it is beneficial for a male to have multiple sexual partners because this will increase the probability that his genes will be passed on. Theoretically, one man could be the father to hundreds (even thousands) of children – the more women he sleeps with, the higher the chances of pregnancy and voila – genes are passed on.


When we give evolutionary explanations of behaviour, we are thinking of the behaviours of our early human ancestors (like homo erectus), which is why sometimes the explanations could seem dated and even sexist when applied to modern societies. (image: wikicommons).

For females, however, they have to be far more selective because they can only have at most one child per year, so whom they procreate with is a far more important decision. Even though we see from the results above that they most must have found the men attractive (because they wanted to go on a date with them), this is not enough for a woman because she spends so much time and energy giving birth and raising the baby she also might benefit from choosing a mate who will be protective, supportive, caring and who will help raise the baby. These differences in gender roles in child bearing and rearing might explain the differences in responses to sexual offers shown in the above studies.


Critical Thinking Considerations

  • What are some possible alternative explanations of these results? For example, is safety a different concern for men and women? Could enculturation or socialization explain these results?
  • Do all men and women demonstrate the same sexual behaviour? What other factors might explain these differences?
  • The above evolutionary explanations make sense when we are applying them to our early ancestors, but do they really apply in the 21st century? What might be different today that might affect the validity of these explanations?
  • What are the ethical considerations relevant to this study?


Clark, Russell D. Hatfield, Elaine. Gender Differences in Receptivity to Sexual Offers. Accessed online from:

This BBC documentary by Robert Winston (link) did a replication of this study…skip to 3 mins to see. The whole documentary is quite interesting actually and it looks at many factors that affect attraction.