The female orgasm may be a means for selecting mates for committed long-term relationships, according to a new study published in Evolutionary Psychology.
While the male orgasm is necessary for sexual reproduction, the female orgasm is not. Thus, some scholars have argued that the female orgasm is unlikely to be an adaptation, but rather, the evolutionary by-product of the male orgasm. Others have emphasized the adaptive benefits of the female orgasm.
“The incredible variability in orgasm we see among females poses a very interesting evolutionary question. There is still quite a bit of disagreement over whether it has an adaptive function and what that function might be,” said Patrick J. Nebl, an assistant professor in the department of psychology at Elmhurst University. “One of my main interests is exploring evolutionary questions by trying to understand the proximate mechanisms, in this case how female orgasm might promote relationship satisfaction.”
The mate-choice hypothesis of the female orgasm posits that it “functions to select males.” The selection of good long-term mates could occur through various mechanisms. The “Mr. Right” hypothesis suggests that the female orgasm serves as a signal of a man’s value as a long-term mate. For example, female orgasm frequency has been associated with the partner’s family income, self-confidence and attractiveness.
The long-term pair bonding hypothesis forwards that the female orgasm functions to promote commitment to a relationship by encouraging emotional bonding and attachment. High amounts of oxytocin – a hormone involved in emotional bonding – are released during intercourse and orgasm.
The context of short- vs. long-term mating is important to consider given that the “female orgasm may have evolved to help females solve an adaptive problem that is unique to short-term mating, one that is unique to long-term mating, or because it helped females solve adaptive problems within both short- and long-term mating contexts,” write the authors.
In this work, Nebl and colleagues tested three predictions that stem from these two hypotheses, in the context of both short- and long- term relationships.
The study included a total of 175 heterosexual, female undergraduate students at Bowling Green State University, with an average age of 19. Participants were randomly assigned to one of six conditions, manipulating relationship context (short vs. long term) and orgasm frequency (never vs. occasionally vs. almost always).
Participants read a hypothetical scenario describing their relationship with a man named Michael. The short-term condition outlined a one-month relationship while the long-term condition referred to a one-year relationship. Following some general details about the relationship (such as where they met), participants then read about the sexual nature of their relationship (e.g., “In your relationship with Michael, you [never / occasionally / almost always] experience an orgasm.”
Next, participants answered questions relating to relationship satisfaction and commitment, and perceived likelihood of staying in the relationship or ending it. These items were used to create a secondary dependent variable assessing expected relationship duration.
The researchers considered various mediators, including perceptions of a male partner’s commitment and relationship satisfaction. Thus, they included questions assessing these variables (e.g., “How much do you think Michael cares about you?”, “How passionate is your relationship with Michael?”). Participants also responded to items examining their orientation toward short- and long-term mating, and personal experience with orgasm (i.e., easiness/difficulty of experiencing orgasm).
The researchers found that female orgasm was associated with greater relationship satisfaction and a longer expected relationship duration in both short- and long-term relationship contexts. Women’s perception of their partner’s commitment did not explain the association between orgasm frequency and relationship satisfaction or expected relationship duration.
Lastly, women’s love for their partner fully explained the relationship between orgasm frequency and both relationship satisfaction and expected duration. Overall, the authors “found support for the mate-choice hypothesis of female orgasm,” writing that the “differential mediation indicates that this hypothesis operates through promoting long-term pair bonds rather than signaling male partner’s care and commitment.”
“Orgasm is highly variable between females, and many females struggle with difficulty or inability to achieve orgasm. Struggling with sexual satisfaction affects relationship satisfaction – and overall satisfaction – and can be distressing, even leading to self-blame,” Nebl told PsyPost.
“The exact adaptive function of female orgasm (pair bonding, sperm retention, etc.) might not be that important to people outside the field, but I do think that the knowledge that variability in female orgasm may be by evolutionary design, rather than being evidence of dysfunction, may provide some solace to women struggling with their sexual satisfaction.”
He notes, “It is very easy to see one study and try to make firm conclusions, but it is important to remember that we don’t come to scientific consensus until we have a convergence of evidence. This study is designed to contribute a unique piece of evidence to the body of research that already exists. However, we still need to do work to understand the proximate mechanisms by which orgasm might function as an adaptation for females, and replicate results we already have.”
With regard to study limitations, Nebl explained, “I think it is important to view this study in the context of the body of research that already exists. Using the fictional scenarios that we used in this study lack some real-world validity, but the goal of this research was to contribute a unique piece of evidence to the field. I certainly don’t think this study ‘proves’ anything, rather it helps add evidence that orgasm might function as a mate-selection tool that promotes pair bonding.”
The study, “The Effect of Female Orgasm Frequency on Female Mate Selection: A Test of Two Hypotheses”, was authored by Patrick J. Nebl and Anne K. Gordon.