The Menstrual Theory of Impulse Buying

Recent research on willpower suggests that it’s a limited resource that can be depleted. Now there’s evidence that something else affects willpower: women’s menstrual cycles. A new study by Karen Pine and Ben Fletcher finds that the further a woman is in her cycle, the more likely she is to make “impulsive purchases.” Pine and Fletcher believe their results are linked to the resource depletion theory of willpower: “We suggest that, in common with other cognitive competencies, the resources that govern spending may also be menstrual-cycle sensitive, and our data reflect women’s lower self-regulatory resources during the luteal (pre-menstrual) phase.” (HT: Nathan Yang) [%comments]


Great. Another "women can't be in charge because they bleed every month" theory. Get over it, we've been menstrating for longer than people have ceased being monkeys. Lot's of women are brilliant - no matter what week of the month it is. Next will someone explain why men have low impulse control all the time? And before you disagree ... how many women get in bar fights, run out and buy $1000 HD TVs on a whim, trade in their mini-vans for a sports car?



There's a difference between a "theory" and a study which produces evidence backing up said theory. If you don't like the results, produce a study that provides evidence to the contrary.

Also, of course there are women for whom this does not apply. That's the nature of statistics. Great for large samples, means little to single data points.

sean samis

Many years ago I read a memoir of the Vietnam war by Ron Glasser called "365 Days". He had a chapter on why some people broke under fire, and others did not. His observations linked their willpower to their state of exhaustion (or rest) pretty convincingly.

Eileen M Wyatt

The sample was recruited from readers of a "major monthly women's magazine." These rags tend to promote shopping as a panacea, include articles on how one's period makes one crazy or ugly, and assume women have trouble controlling retail spending.

Readers who pay to absorb this message monthly then self-reported that their behavior conformed with it.

Shocker, that.


What's my husband's excuse who I drag out of Costco weekly (period or not) whining, 'but everybody has a flat screen tv...i want a flat screen tv..."


@ Elizabeth,

I think that there's a difference between science and the interpretation of results. This blog simply stated what may be rationally and properly executed science, and you choose to interpret it in the way that you most disagree with.

Your comment reminded me of many a political argument - what is the obsession with conspiracy theories?


the mere fact that this study was conducted tells you the bias. Prove me wrong, Tim, and show us the male control group of this study.

What a load.


@KMayer: He doesn't want to be stuck watching a bulbous relic from the eighties when there's better technology available? I bet Thag's wife complained about his need for a flat-flint spear as well when a shapeless rock had been perfectly all right for hunting mammoths until then. Sigh, when will you understand?

Gayle Kolidas, LCSW

Women have PMS a few days a month - men have it all the time -

This is really not up to your usual standard. Better luck next time.


wouldn't surprise me, actually, though I wish the study had been done better. It doesn't sound like they know whether the increased spending is linked to ovulation (when hormones tend to lower sexual inhibitions to make reproducing more likely) or truly to the luteal phase, which is when a women is least likely to get pregnant. Hopefully someone will do further research, possibly through the groups that teach fertility awareness methods of birth control, since they have a large (well, large-ish) base of women who are already tracking ovulation


Let's not get hysterical.* This study is not comparing women to men or even women to other women. The conclusion boils down to: "hormone levels have an effect on decision making." This should not be a suprise to anyone.

*get it?

David Chowes, New York City

Anecdotaly seems to be congruent with my experiences viv-a-vis woman during certain stages of the menstrual cycle.

Key word: "shoes."

Drill-Baby-Drill Drill Team

We all have our biological clocks. But for women, it is London's Big Ben compared to a Timex Wrist Watch for men.

Women have a small window of fertility beginning at adolescence and continuing to the late 30s. Women have only 400 eggs which sequentially mature. Each menstruation is a tick-tock of the biological clock....And the loss of one more potential offspring. And women are more aware of this window for motherhood from a very early age. Women mature faster physcially and psychologically because of the biological clock. And they may be impulsive to get married and have children and become a matriarch and a grandmother etc. Shopping may be part of this impulsive destiny.

Men by contrast produce semen continuously throughout life. The quality of sperm is poor both in the early part of life and late part of life, but the fertility window may be 40-50 years. Men suffer from wanderlust and like an old dog, stray. And they may have multiple generations of families with separate wives.

So both sexes think different about reproduction as in many things in life. .... But I still can't explain why woman like shoes so much.



Roseanne Barr used to say about PMS, "It's the one time of the month I can get away with being myself."

I wonder

I wonder what kinds of purchases these are. "I'm tired, so let's eat out"? "I'm feeling stressed, so I bought a pricey coffee as a pick-me-up"? "I'm unhappy, so I decided to indulge myself in a little luxury"?

I wonder, in short, whether they controlled for any of the factors that (1) are known to increase impulsivity and (2) are also known to be more common in the post-ovulatory state?



I think you're getting overly defensive about a simple experimental study. Moreover, nowhere in this entry or the study was it suggested that these observations could (or should) be used to justify discrimination against women.

If I observe that women are generally able to lift less weight as measured by Olympic lifting standards, I bet your response would be, "Great. Another 'women are the weaker sex' theory. Get over it, women have been having babies and doing farm work for longer than people have ceased to be monkeys. Lots of women are strong."

Get over it. There ARE fundamental differences between women and men. Some can be seen as positive, some as negative. Acknowledgement of them doesn't make a person sexist. Prejudgement of an individual based on gender does, but the two are not the same.


@Allison (#7): "The mere fact that this study was conducted shows you the bias."

In other words, any study that seeks to show correlations between gender and behavior are biased, or any study that asks a controversial question is inherently biased? And if the results don't seem to support YOUR opinion, then it automatically MUST be biased.

Since when is it discriminatory or biased to ask a question? There ARE no biased questions. Only biased preconceptions.

It is a fact that menstruation involves significant hormonal fluctuations. It is also a fact that hormonal fluctuations can influence thinking, emotion and behavior. It is therefore not any indication of bias to ask whether or how menstruation might affect any aspect of behavior.

I bet you wouldn't have thought it was biased if the study asked whether men experienced decreased impulse control after, say, watching an entire Sunday's worth of football.



I agree that this study was, in a sense, biased. And certainly flawed. If the women were in a certain part of their cycle, how can we be sure their responses weren't due to their mood, rather than the qualification that their purchase was unwise?

In other words, women are likely to be more unhappy with their purchases if their mood is lousy. How can we be sure this was not the case here?

This study seems to have high potential to use leading questions - I cannot say for sure without reading the study, of course, but the mere act of asking women to link their periods with how they feel about their shopping habits, seems to make the most of tired stereotypes.

From their abstract:

"At ovulation, or peak fertility, it has been shown that women adapt their dress style to impress men - known as the ornamentation effect."

I would have to track a whole lot of literature to get at the entire picture of their references and claims - but really, these studies sound rife with potential for too many assumptions about women.

The entire abstract is here:


Eileen M Wyatt

If the argument is that female behavior is cyclically hormonally driven, why does the study not control for use of the pill? It's used by almost 1/3 of U.S. women in peak reproductive years, and it works by changing the hormone cycle.

Panem et Circanses

The Seven Sisters / New York Times view of women is NOT shared by all WOMEN nationwide, let alone men. Yes, there ARE differences - get over it!