The man and woman sat together at a table and were given a few minutes to interact, so the man could discern fertility cues, if there were any. To make cues as noticeable as possible, the women refrained from using makeup, perfume, or scented shampoo.
Researchers then gave each partner a stack of line drawings depicting simple scenes—one child giving another child a toy, for example. The woman was asked to provide a one-sentence description of each picture (“Meghan gave Michael a toy”), and the man responded by doing the same with one of his own pictures. As he did so, the researchers compared the structure of his sentences to that of the woman’s.
When the women were less fertile, men copied their sentence constructions 62% of the time. But the rate dropped to just under 50% when the women were at peak fertility.
What’s more, when the researchers repeated the experiment with women only, fertility had no discernible impact on sentence structure. “It didn’t show the same effect at all,” Kaschak says. “The effect was specific to men.”
There is a catch, however: Men in the first experiment who thought their partner was being flirtatious were actually more likely to match their sentence structure to hers. In this scenario, Kaschak says, the male’s priority might be to reciprocate the female’s interest rather than draw added attention to himself.
“If the woman seems noncommittal, then maybe the correct strategy is to do something to try to stand out a little bit, to try to get her attention,” he says. “Maybe you can drum up some interest.”
The findings will likely be of interest to language researchers, especially those who study so-called “linguistic alignment” in relationships, Kaschak and his coauthor suggest. For the rest of us, they’re a reminder that conversations between men and women are often more complex than they might seem on the surface.
“A lot of the behavior that we exhibit when we interact with other people happens on an unconscious level,” Kaschak says.