Purchasing designer handbags and shoes is a means for women to express their style, boost self-esteem, or even signal status. New University of Minnesota research suggests some women also seek these luxury items to prevent other women from stealing their man.

Through a series of five experiments featuring 649 women of varying ages and relationship statuses, Carlson School of Management Associate Professor Vladas Griskevicius and PhD student Yajin Wang discovered how women’s luxury products often function as a signaling system directed at other women who pose a threat to their romantic relationships.

“It might seem irrational that each year Americans spend over $250 billion on women’s luxury products with an average woman acquiring three new handbags a year, but conspicuous consumption is actually smart for women who want to protect their relationship,” says Griskevicius, coauthor of The Rational Animal: How Evolution Made Us Smarter Than We Think. “When a woman is flaunting designer products, it says to other women ‘back off my man.’”

Griskevicius and Wang first investigated what other women infer about a woman’s relationship partner based on the luxuriousness of her possessions. “We found that a woman who is wearing luxury items and designer brands is perceived to have a more devoted partner and as a result other women are less likely to flirt with him,” says Wang. “Regardless of who actually purchased the items, other women inferred that the man had something to do with it and is thus more devoted to her.”

In another study, Griskevicius and Wang made participants feel jealous by having them imagine that another woman was flirting with their man. Shortly afterward, the women completed a seemingly unrelated task in which they drew a luxury brand logo on a handbag. The result? When women felt jealous, they drew designer logos that were twice the size of those in the other conditions.

“The feeling that a relationship is being threatened by another woman automatically triggers women to want to flash Gucci, Chanel, and Fendi to other women,” explains Wang. “A designer handbag or a pair of expensive shoes seems to work like a shield, where wielding a Fendi handbag successfully fends off romantic rivals.”

Another of Griskevicius and Wang’s studies revealed that when romantic relationships were threatened, women not only desired more expensive handbags, cars, cell phones, and shoes, they also spent 32 percent more of their own money for a chance to win an actual luxury spending spree.

This research highlights that luxury products serve an important function in relationships, but that men and women use conspicuous consumption for a different purpose. Past research by Griskevicius has found that men often seek expensive products to show off to the opposite sex in order to attract them as mates. The current studies reveal that women often seek expensive products to show off to the same sex in order to protect their turf.

“The fact that most women’s luxury products are aimed to impress other women helps explain why men have a hard time figuring out if a woman’s handbag costs $50 or $5,000,” adds Griskevicius. “Women’s designer products are geared to show off to other women not men.”

A surprising finding in the paper was that feelings of jealousy triggered a desire for luxury products not just for women in committed relationships but also for single women. “Many single women obviously want designer products, but instead of these products saying back off my current man, the single woman is saying back off my future man,” adds Wang. “Conspicuous consumption for women has a lot to do with subtle status within the female group.”

“Conspicuous Consumption, Relationships, and Rivals: Women’s Luxury Products as Signals to Other Women” is currently in press at the Journal of Consumer Research.