By Alex Fradera

In 1914, the psychologist Leta Hollingworth’s experiments punctured holes in the prevailing idea that menstruating affects women’s intellect. But a century on, the ovulation cycle continues to interest psychologists, who today focus on how it affects sexual behaviour. A popular evolutionary psychology theory states that during fertile periods, women become more interested in men who use dominant masculine behaviour, as this signals they are likely to provide good genes for any offspring. A University of Goettingen team have now conducted the largest ever test of this idea, published as a pre-print at PsyArxiv.

The “good genes ovulatory shift hypothesis” or GGOSH suggests that during fertile phases of the menstrual cycle women should be especially attracted to potential mates who are likely to provide good genes to their offspring. The hypothesis further states that such genes are signalled through men’s sexual assertiveness and confidence, via behaviours like flirting, smiling and directly gazing at women.

The evidence for GGOSH is sketchy. There are two relevant meta-analyses, both published in 2014 – one in Psychological Bulletin, the other in Emotion Review – but only the first supported the hypothesis.

Enter the new study, led by Julia Jünger. Employing a stronger design than past research, her team tested the same subjects repeatedly (at different times in their cycle) rather than relying on different participants. They also used larger sample sizes and collected hormone data via saliva samples to validate the self-reports of where the women were on their cycle. The study was also pre-registered and the data made available for other researchers to review.

The 157 participants, heterosexual women aged 18-35, took part twice, in the fertile and the luteal (non-fertile) phases of their menstrual cycle. On each occasion, the women saw a series of 30-second video clips of single men in real interactions with an attractive woman they’d just met (however the woman was not visible in the clips). The men’s behaviour varied in the amount they smiled, the time they spent gazing at the woman’s face, how much they spoke during the clip, and other flirtatious actions.

During the more fertile period of their cycle, the women found the men more sexually attractive – on average, they were more interested in pursuing a potentially short-term and purely sexual relationship with them (a pattern that was mediated by the levels of the hormone estriadol in their saliva: more estriadol correlated with more attraction), and they were more interested in long-term relationships with them too.

This fertility-attraction link confirms a well-established finding, but the GGOSH makes a much more specific prediction – that women will find dominant, flirtatious behaviours in particular more attractive during fertility, and here the data suggested otherwise. Eye contact, confident body language, smiles – none of these mattered more during greater fertility, against the predictions of the hypothesis.

The GGOSH also predicts that good-gene markers will be particularly valued by fertile-phase women who are already in a relationship (the idea is that they already have a safe nest in which to raise a kid, so will not be too fussed that dominant mates with good genes may be less reliable). In fact, the dominant “good genes” behaviours weren’t any more attractive to partnered women during their fertile phase. This is two firm strikes against the hypothesis.

However, the women’s relationship status did make a difference to their overall levels of attraction in the men – when the researchers conducted their analyses separately for partnered and single women, they found that it was only partnered women whose overall sexual interest in the men increased during the fertile phase of their cycle, perhaps, the researchers suggested, because having a partner they can rely on to raise a family increases women’s interest in sex (though it would be easy to have come up with an ad-hoc evolutionary explanation for the complete opposite result, so I would suggest waiting for this finding to be replicated before drawing conclusions).

Returning to the GGSOH, while this research reaffirmed that the ovulatory cycle affects women’s interest in sex, thanks to shifts in hormones, it does not support the hypothesis that it swivels their minds towards a different object of desire. So if any aspiring pick-up gurus were hoping to build a creepy philosophy around switching up your style at points in the cycle, they will be disappointed. And women shouldn’t be concerned that during times when their body is amping up sexual desire it is also dictating who that desire should be projected towards.

—No evidence for ovulatory cycle shifts in women’s preferences for men’s behaviors in a pre-registered study [this study is a pre-print meaning that it has not yet been subject to peer review]

Alex Fradera (@alexfradera) is Staff Writer at BPS Research Digest