When I was in college, credit card companies would lure students into opening accounts by giving away t-shirts or 2-liters of Coke in exchange for signing up for a new card. Nearly 20 years later I still have one of those accounts, although the t-shirt is thankfully long gone. I attended an engineering school that had nearly a 2-to-1 male to female sex ratio; there were twice as many young men on campus than women. Did this imbalance affect the likelihood that my fellow single men would get into trouble with their new credit cards? Could it be because of “intrasexual competition” (i.e., competing with other men) for relatively few available females?