A new study has found that women with stable but not-so-sexy mates become more distant and more critical during periods of high fertility.
“A woman evaluates her relationship differently at different times in her cycle, and her evaluation seems to be colored by how sexually attractive she perceives her partner to be,” said Martie Haselton, Ph.D., a professor of psychology and communication studies at the University of California-Los Angeles and senior author of the study.
Fortunately for the men, the negative feelings are fleeting and don’t seem to affect a woman’s long-term commitment to her romantic relationship, the study found.
“Even when these women are feeling less positive about their relationship, they don’t want to end it,” said Christina Larson, the study’s lead author and a doctoral candidate in social psychology at UCLA.
Through a series of studies, Haselton’s lab has revealed changes that take place in women’s behavior during ovulation. Possibly to increase the odds of attracting suitable mating partners, these behaviors include a tendency to dress up and to speak in a higher-pitched, more feminine voice and — in a potential inbreeding-avoidance mechanism — to refrain from contact with male relatives.
In addition, the lab has found that women whose mates are less sexy and masculine tend to be more attracted to other men during the fertile days leading up to ovulation.
The researchers began the latest study by pinpointing the ovulation cycles of 41 undergraduate women involved in long-term heterosexual relationships. They asked the women to rate the sexual attractiveness of their mates by answering such questions as “How desirable do you think women find your partner as a short-term mate or casual sex partner, compared to most men.”
They also asked the women a series of questions designed to measure their partner’s stability or suitability as a long-term mate, including questions about how his present and future financial status compares with that of most men.
Then at two different points in her monthly cycle — at high fertility (just before ovulation) and at low fertility — each woman was asked about the quality of her romantic relationship.
The researchers, who used a questionnaire designed exclusively for the study, found no significant change across the cycle in how the women perceived their level of commitment to the relationship or, at least initially, in their satisfaction with it.
But in another exercise that required the women to rate how close they felt to their men, the researchers discovered that as women mated to less sexually attractive men moved from their least fertile to most fertile period, their closeness scores dropped one point on a seven-point scale.
Women mated to the most sexually attractive men, meanwhile, experienced the opposite effect. As these women moved from their least to most fertile period, their closeness scores rose by a point, the researchers said.
“Women with the really good, stable guy felt more distant at high-fertility periods than low-fertility periods,” Haselton said. “That isn’t the case with women who were mated to particularly sexually attractive men. The closeness of their relationships got a boost just prior to ovulation.”
To ensure that the findings were not an anomaly, Haselton and Larson repeated the experiment with 67 other co-eds in long-term relationships. This time the researchers administered a better-recognized measure for relationship satisfaction than the one they originally used. They also administered a questionnaire aimed at illuminating a dimension not studied in the first round — pickiness.
What they found is that women mated to the less sexually attractive men were significantly more likely to find fault with their partners and feel less close to their partners during the high-fertility period than the low-fertility period. Women who rated their mates as more sexually attractive, meanwhile, did not exhibit these changes and instead reported being more satisfied with their relationship at high fertility than at low fertility.
The researchers say the findings shed light on a number of conflicting behaviors that stem from mating strategies that might have provided an evolutionary benefit long ago.
“Since our female ancestors couldn’t directly examine a potential partner’s genetic makeup, they had to base their decisions on physical manifestations of the presence of good genes and the absence of genetic mutations, which might include masculine features such as a deep voice, masculine face, dominant behavior and sexy looks,” said Haselton.
“It is possible that we evolved to feel drawn to these visible markers because, at least in the past, they proved to be indicators of good genes. Ancestral women who were attracted to these features could have produced offspring who were more successful in attracting mates and producing progeny.”
But it’s no secret that women look for more than good genes when choosing a partner.
“In the reproductive arena, women probably evolved to desire men who could contribute both quality care and good genes,” Haselton said. “The problem is that there is a limited number of potential mates who are high in both, so many women are forced to make trade-offs.”
She calls the urge for a stable long-term partner, along with the increased desire for a more sexually attractive mate during periods of high fertility, the “dual mating hypothesis.”
The researchers next study will look at whether fault-finding and the feelings of distance and dissatisfaction have any long-term destabilizing effects on relationships. They also plan to look into how the behavior is perceived by the male partners of these women.
“We don’t know if men are picking up on this behavior, but if they are, it must be confusing for them,” Larson said.
The findings are scheduled to appear in the journal Hormones and Behavior.