In the past, there has been much excitement over research that purported to show a link between changes in a woman’s cycle and how attracted she was to men behaving in different ways.
However, research at the University of Göttingen using the largest sample size to date questions these results. The new research showed that shifts in women’s cycles did not affect their preferences for men’s behaviour.
The researchers found, however, that when fertile, women found all men slightly more attractive and, irrespective of their hormone cycle, flirtier men were evaluated as being more attractive for sexual relationships but less attractive for long-term relationships. The results were published in Psychological Science.
According to the good genes ovulatory shift hypothesis (known as GGOSH), women’s preferences for certain behaviours, presumed to indicate men’s genetic fitness, should differ according to their fertility.
To test this, the researchers studied 157 female participants who met strict criteria – including being 18 to 35 years old, heterosexual and having a natural, regular cycle.
The participants watched videos showing a man getting to know a woman who was out of shot. In four separate testing sessions, the female participants rated the men both on sexual attractiveness for a short-term relationship without commitment, and on attractiveness for a long-term relationship.
The participants were asked to focus on the way the men behaved. The researchers used saliva samples to analyse current hormone levels and highly sensitive urine ovulation tests for validating the ovulation date, and in particular the fertile period.
They found there was no evidence that a woman’s mate preference changes across the ovulatory cycle. Rather, women seem to perceive or evaluate every man as slightly more attractive when fertile compared to other cycle phases.
They also found that men who act in a more competitive manner and show more courtship behaviour (for instance flirting) were evaluated as being more attractive for short-term sexual relations but less attractive for long-term relationships, independent of cycle phase or hormone levels.
To test whether women’s preferences for certain behaviours differed according to their fertility, the researchers used saliva analysis to analyse hormone levels and highly sensitive urine ovulation tests to pinpoint the ovulation date.
First author Dr Julia Stern from the University of Göttingen’s Institute of Psychology said, “There is a lot of research on women’s mate preferences, so at first we were surprised that we didn’t see the same effects. However, our new results are in line with other recent studies using more rigorous methods than previous studies.”
Stern added, “The finding that ratings of attractiveness increase in the fertile phase, independent of men’s behaviour, is new and indicates that women’s mating motivation is likely to be higher in the fertile phase.”
Apart from using well a large sample that met strict criteria, the researchers followed rigorous methods, for instance by preregistering their study before data collection and employing “open science” practices such as making their data and analyses publicly available.
One of the most noteworthy differences between humans and other closely related primates is the absence of clear advertise- ments of fertility within the ovulatory cycle (Dixson, 1998). Recent evidence has suggested, however, that there are subtle ovulatory cues in humans. Roberts et al. (2004) showed facial photographs of women taken during the follicular and luteal phases to male and female judges.
On average, follicular phase images were judged more attractive approximately 54% of the time. Similarly, relative to those from other cycle phases, women’s body scents near ovulation are judged as more attractive by men (Doty et al., 1975; Singh and Bronstad, 2001; Thornhill et al., 2003) and women’s sexual desires vary across the cycle (Bullivant et al., 2004; Gangestad et al., 2002;
Haselton and Gangestad, 2006). Thus, human ovulation may not be completely concealed.
In the last decade, the literature on cyclic shifts in women’s social motivations has grown rapidly.
For ancestral women, the time required to collect food could have been considerable; thus, Fessler (2003) reasoned that there likely were tradeoffs across the cycle between feeding and other activities such as mating. Fessler (2003) compiled and reviewed evidence that women’s appetites decrease near ovulation, and he hypothesized that this decrease in appetite at high fertility reflects an adaptation in women designed to decrease the motivational salience of goals that compete with efforts devoted to mating.
As additional evidence supporting the hypothesis, Fessler reviewed studies showing that women’s ranging activities, such as locomotion and volunteering for social activities, tend to increase near ovulation.
Other lines of evidence also indicate cyclic shifts in women’s mating motivations. In a daily report study, Haselton and Gangestad (2006) found that on high fertility days of the cycle women report a greater desire to go to clubs and parties where they might meet men.
Macrae et al. (2002) found that women’s ability to categorize male faces and male stereotypic words is faster near ovulation, suggesting increased attentiveness to “maleness” at high fertility. Other research shows that women’s preferences for masculine features (e.g., masculine facial structure) increase near ovulation (reviewed in Gangestad et al., 2005a). Several rigorous within-subjects studies have found that women’s attraction to and flirtation with men other than their primary partner is higher near ovulation than in other phases of the cycle (Gangestad et al., 2002; Haselton and Gangestad, 2006; also see Bullivant et al., 2004). Finally, Fisher (2004) found that women tested near midcycle, compared with those tested in other cycle phases, tend to give lower attractiveness ratings to photographs of female faces—an effect Fisher interpreted as evidence that women are more intra- sexually competitive near ovulation. In sum, a variety of data sources indicate that women’s social motivations – in particular, their sexual motivations – increase near ovulation.
Hypothesis: ovulation and ornamentation
We hypothesize that changes in women’s motivations manifest themselves in changes in self-ornamentation through attentive personal grooming and attractive choice of dress.
Ornamentation in non-humans, including bright plumage, long tails, and large bodies, is generally presumed to be the product of sexual selection (Andersson, 1994). These traits are effective in attracting mates, either because they indicate fitness (e.g., due to costs of their maintenance) or due to pre-existing sensory biases (Daly and Wilson, 1983; Parsons, 1995; Zahavi, 1975).
Although rare, animals occasionally employ behavioral orna- mentation, as opposed to morphological ornamentation, in the effort to attract mates. Male bowerbirds, for example, found in Australia and New Guinea, build elaborate structures ornamen- ted with brightly colored flowers and fruits in order to attract mates.
Male bowerbirds will often also pick up a brightly colored object in their beaks while displaying to a female, thus effectively ornamenting themselves (Diamond, 1982; Gilliard, 1969). The purpose of these traits, both morphological and behavioral, is to attract reproductive partners, and animals do not expend energy producing these displays when mating is not likely.
The bowerbird dismantles its bower and abandons its territory during the non-breeding months (Pruett-Jones and Pruett-Jones, 1982), and even birds that rely on morphological ornamentation, such as brightly colored feathers or bills, may exhibit sexual dimorphism only seasonally (Badyaev and Duckworth, 2003; Peters et al., 2004).
In humans too, ornamentation may serve the purpose of attracting mates, at least in part. In a recent study, Grammer et al. (2005) interviewed women at a discotheque; those who rated their clothing as “sexy” and “bold” also reported that their intention for the evening was to flirt or find a sex partner.
Although the direction of causality is unclear, these findings suggest that women’s clothing choices are linked with their motivations.
Prior research also has shown that men’s behaviors toward their partners shift across the cycle. Three studies have shown that, in the fertile relative to the luteal phase of the cycle, men are more attentive and loving toward their partners (Gangestad et al., 2002; Haselton and Gangestad, 2006; Pillsworth and Haselton, 2006) and two have shown that men are more jealous and possessive (Gangestad et al., 2002; Haselton and Gang- estad, 2006).
It is not yet known what cues drive these changes in men’s behavior. One possibility is that men attend to differences in female behavior. For example, Haselton and Gangestad (2006) and Gangestad et al. (2002) found that women’s reports of flirtatiousness with men other than their primary partner were higher when assessed during the late follicular as compared with the luteal phase of the cycle.
In both studies, ovulatory increases in flirtatiousness statistically predicted ovulatory increases in male mate retention effort but did not fully account for them, leaving open the possibility that other ovulatory cues affect men’s behavior—including the ornamentation effect we predict.
In this study, we measure an overt, readily observable behavior in women that we propose will be linked with ovulation. Specifically, we predict that women engage in self- ornamentation during the high fertility phase of the ovulatory cycle, thus placing themselves in the foreground of the social array.
University of Gottingen