A recent study published in Adaptive Human Behavior and Physiology suggests that heterosexual men, on average, tend to be more attracted to women who are near their ovulation period (compared to other phases of their cycle) due to unconscious triggers, not due to the conscious seeking-out of women who are flashing phase-specific biological signals.
This new research is based on a larger body of research into human ovulation cues—or “fertility cues”—that are found in most mammals and which indicate, essentially, when the ovulating half of a sexual pair is ready to procreate.
There’s some controversy surrounding this topic, as there’s research supporting both the ovulatory shift hypothesis, and those who hypothesize that humans have either weeded-out these effects over the generations, or that their impacts are so small in contemporary humans that they’re barely worth measuring.
If this hypothesis does prove to be accurate, though, the potential ramifications are substantial, as it suggests that women who are entering their fertile stage undergo a collection of subtle (and sometimes less-subtle) physiological changes in the shape of their face, the pitch of their voice, and the chemical signals communicated in their body odor, among other adjustments.
These changes may also tweak women’s social behaviors, fitness and dietary routines, mate preferences (what they’re attracted to in a partner), how they dress, and tendency to cheat or seek out one night stands.
In parallel—again, according to this hypothesis—men tend to experience their own portfolio of changes, seemingly in response to cues from women in their lives (their partners, but also non-partners like family members and friends).
Among other changes in men with partners who are at their most fertile is a tendency to be more jealous, which includes the production of higher levels of testosterone when shown photos of other, attractive men.
The general idea here is that, as is true with many animals, humans have all sorts of subtle, subconscious signals that allow them to communicate what’s happening on the reproduction front to each other, and those signals, when received, can catalyze changes in those around the signal-sender.
Some recent studies have suggested that earlier findings in this space—like women experiencing changes to the type of man they find most attractive while fertile—don’t hold up to renewed scrutiny, so there’s a chance a number of the claims in this space, once they’re re-tested and assessed using more modern methods (and a larger number of test subjects) will likewise fall by the scientific wayside.
That said, there’s enough research-heft underpinning some of these claims—including the broad, baseline idea that human beings in general change habits, preferences, and physiology during different phases of their hormonal rhythms, and that we tend to communicate these changes to each other in various ways—that not all of them can be outright discounted as ridiculous, even if many of them may initially seem farfetched or disempowering, in the sense that they imply a periodic scrambling of our capacity for rational thinking (which is honestly something we should probably assume much of the time, anyway, for all sorts of other reasons).