Women often seek expensive, luxury clothes, shoes and handbags to show off to the same sex in order to protect their turf and their man, U.S. researchers say. Professor Vladas Griskevicius and doctoral student Yajin Wang at the University of Minnesota 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 U.S. shoppers spend more than $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,\" Griskevicius said in a statement. \"When a woman is flaunting designer products, it says to other women \'back off my man.\'\" The researchers conducted a series of five experiments featuring 649 women of varying ages and relationship status and found 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 her partner, Wang said. \"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,\" Wang said. \"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.\" The study, \"Conspicuous Consumption, Relationships, and Rivals: Women\'s Luxury Products as Signals to Other Women,\" is in press at the Journal of Consumer Research.