According to a recent study published in Evolutionary Psychological Science, women report a greater tendency to engage in risky sexual behaviors with more attractive partners, and when they use their own sexuality as a means of mate retention.
Parental investment theory posits that women are the more discriminating sex in selecting mates given they invest more so in offspring (i.e., gestation and lactation). In contrast, the minimum parental investment for men could just be one successful copulation. Thus, men are more likely to engage in causal sexual opportunities, while women are less likely to seek sex outside committed relationships.
Women’s mate preferences differ for long- and short-term partners. For long-term romantic relationships, women have a preference for men who exhibit resource acquisition potential, and men who have positive traits, such as maturity and kindness. For short-term relationships, women have a stronger preference for indicators of good genes, such as physical attractiveness, masculinity, intelligence, and dominance – these traits signal genetic quality that could provide offspring with survival advantages. Traits such as bilateral symmetry and masculinity are indicators of developmental stability and long-term health, and immunocompetence respectively.
Some studies suggest that in the late-follicular phase of the menstrual cycle (i.e., when a woman is fertile), women experience an increase in their preference for putative cues of immunocompetence for short-term relationships. For example, women report stronger preferences for men who have masculine and symmetrical traits, and are more attracted to dominance, closer to ovulation.
Researchers Sylis Claire A. Nicolas and Lisa L. M. Welling write, “women are more sexually motivated and active when conception is more likely, and it is likely that this relationship is contingent on the fitness indicators (i.e., putative cues to immunocompetence) of women’s partners.”
Sexual risk-taking is a common phenomenon, with women reporting greater willingness to risk pregnancy with physically attractive men, and men who show commitment, good financial prospects, as well as moderate to high social status.
“The present study was designed to provide a preliminary investigation into factors that predict sexual behaviors that could lead to unintended pregnancies among committed, romantic couples,” write the researchers. They conceptualized sexual risk-taking as behaviors that could result in pregnancy or a sexually transmitted infection. Information on women’s menstrual cycle phase was collected for exploratory purposes.
A total of 204 participants were included in this study; the mean age was 20.7, while the average relationship length was 25.2 months. Participation was limited to those who had been in a heterosexual, sexually involved relationship for at least 3 months, women between ages 18-35 (to maximize the number of women who could become pregnant), those who were naturally cycling, and women who had not been using contraceptives for at least 3 months.
Participants’ partners could not have had a vasectomy or be on any treatments relating to infertility. Women who had given birth in the past 9 months, or were pregnant or breast-feeding could not participate, as these affect ovulation. As well, women who were trying to become pregnant were excluded given this would prevent the assessment of unintentional pregnancy. The authors highlight, “These exclusion criteria increased the likelihood that couples were all reproductively capable.”
Participants began the study by providing demographic information (e.g., age, ethnicity, relationship status). Afterwards, they completed various measures presented in random order, assessing participants’ “sex lives, menstrual cycles, sexual risk-taking, relationship satisfaction, and partner quality” and “questionnaires related to the potential confounds of religiosity, attitudes toward pregnancy, mate retention behaviors, contraceptive self-efficacy, sociosexual orientation, general risk-taking, and sensation-seeking.”
Women reported engaging in risky sexual behaviors with more attractive partners, and when they used “sexual inducement” as a tactic to retain their partner. This suggests sexual risk-taking functions as a mate-retention strategy in order to increase the relationship satisfaction of their partner. Women who were more socially dominant were more likely to engage in conception-risking behaviors and “would be less upset by an unintended pregnancy.”
Conception risk-taking at the time of participants’ last sexual encounter was positively associated with their partner’s dominance; however, this finding was not statistically significant – thus, the authors warn it ought to be interpreted cautiously.
Women of higher religiosity, those who took fewer social risks, and those with partners of higher masculinity were more likely to carry an intended pregnancy to term. And despite all participants indicating that they were not intending to become pregnant in their current relationship, 119 of 204 participants reported engaging in at least one behavior that increased their risk of becoming pregnant at the time of their last sexual encounter. Additionally, fertility status did not predict initiating sex, sexual risk-taking, or relationship satisfaction.
One limitation is that participants estimated their menstrual cycle phase; often, women do not provide the correct cycle length, especially at the end of their cycle. As well, the full range of potential sexual risk-taking behaviors that could increase the risk of unintended pregnancy were not captured by the measures used.
The authors conclude, “Results lend some support to other work demonstrating that women’s sexual behaviors, preferences, motivations, and cognitions are somewhat conditional on the putative genetic quality of their long-term partners.”
