Risky Pheromones: Was Juliet Ovulating When She Met Romeo?

Does the scent of an ovulating woman influence how a man thinks, and the risks he’s willing to take?

By Douglas Kenrick — Written on Feb 28, 2011

There's a lot of recent research showing that women behave differently when they are ovulating – dressing in more provocative ways, boosting their desire to head out to parties, staring more at handsome symmetrical men, and feeling a boost in attraction toward strangers (if those strangers are handsomer than their current partners). A new series of studies by Saul Miller and Jon Maner systematically explore the other side of the equation – how men respond to cues of ovulation in women. One of their more interesting findings is that the mere presence of an ovulating woman can boost a man’s economic risk-taking.

In one study, men interacted with a female student who was in cahoots with the experimenters. The woman had been keeping track of where she was in her ovulatory cycle, and been instructed not to wear any perfumes, not to eat any odor-laden foods, not to wear make-up, and to dress in the same non-provocative way for every session (wearing a plain t-shirt and a pair of jeans, with her hair pulled back in a pony-tail). She had also been trained to act in a consistent and non-flirtatious way with each male subject. The men were led to believe she was simply another subject who had signed up to be in the same experiment at the same time as they did.

One of the experimental tasks involved spending 5 minutes building a structure out of Lego blocks. While working on the task, the female put her left elbow on the desk, placed her left hand so that it covered her chin and cheek, and proceeded to slowly piece together Legos with her right hand. Using a hidden camera, the experimenters recorded whether the man mimicked her nonverbal behaviors (previous research has shown that we are more likely to adopt the postures of people when we want them to like us). After that, the man was asked to play a game of Blackjack on a computer with the female sitting behind and watching his choices.

Men were more likely to mimic the woman’s nonverbal posturing on the days when she was ovulating, suggesting they were more interested in her. Most interestingly, the woman’s ovulatory cycle influenced the men’s economic decisions – the guys made riskier decisions on days when the woman was ovulating. For more about this research, see my Psychology Today blog: Sex, Murder, and The Meaning of Life....Another recent series of studies suggests that ovulation also alters women’s economic decisions –inspiring more to spend more money on sexy clothing, especially when there are other attractive competitors around (see When women are in heat, the economy warms up).

Findings such as these are in line with what my colleagues and I call Deep Rationality – the view that economic decisions, although irrational on the surface, often reflect an underlying evolutionary logic. I discuss this more broadly in my soon-to-be-released book, Sex, Murder, and the Meaning of Life. (My son, who studied film production at NYU, made up what I think is a very cool and colorful video about the book, which you can check out by clicking here - be sure to have your speakers turned on).

I Only Have Eyes For You: Ovulating Women Stare, But Don’t Remember

Deep Rationality, Evolutionary Psychology Meets Behavioral Economics

Deep Rationality II: Conspicuous Consumption as a Mating Display.

When Women are in Heat, the Economy Warms Up

My website, where you can learn more about my research and books

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