Interestingly, a growing area of research suggests how our brains are hardwired for imitation. The key ingredient seems to be mirror neurons, first studied by Italian researchers Giacomo Rizzolatti and his colleagues in the mid-1990s. Further studies by Vilaynur Ramachandran and others show how significant imitation is both in human development and in the origins of civilization. The basic insight is this: our brains are stimulated by perceiving others doing things that elicit our desires.

The developmental period of young adulthood is particularly prone to pluralistic ignorance when there is no compelling alternative model for young adults to imitate. My hypothesis, which needs further study, is that what drives college-age hooking up is not exclusively the pleasures of drinking and sex per se, but rather the craving for social acceptance. Anecdotal evidence in books by Laura Sessions-Stepp and Donna Freitas (linked above in the drinking/hookup references) suggests this connection, especially among young women, but also among some men, and my many years of working with college students further suggests it.

Will single-sex dorms solve the problem of pluralistic ignorance? No, but it can help to interrupt the process. Christopher Kaczor argues persuasively that same-sex dorms might reduce the prevalence of binge drinking and hookups in a recent article. The article relies on studies that isolate differences in rates of those behaviors among students in single-sex dorms compared to coed dorms over a 12-month period. But in my view, the more persuasive argument regards what will happen over a period of many years. The key question, it seems to me, is not "does your college have single-sex dorms?" but rather "what does your college do to encourage practices of friendship and positive relationships between the sexes?"

In a recent essay in the journal Human Development, I argue that practices of friendship are the pedagogy for marriage [opens a PDF]. Single-sex dorms can likely reduce the easy, thoughtless hookup by virtue of the fact that students will not be able to stumble in a stupor into the bed of a member of the opposite sex. But "lack of opportunities for thoughtless and harmful hookups" is hardly a selling point for parents eager to see their children develop into mature adults. What is needed, in addition to single-sex dorms, are adults who model friendship and marriage; plenty of alcohol-free activities, especially at late night and on weekends; classes at 8 and 9 a.m., especially on Fridays; positive programming that allows for cultivation of different friendships, platonic and even romantic; ample conversation in classes and events about marriage and sexual fidelity; and a host of other initiatives.

Aristotle was certainly right that human beings are not only brains with bodies attached; they are shaped by practices and especially by friendships (see Nicomachean Ethics, books 8 and 9). What makes college life today so depressing for many is not just the drinking and the sex: it's the lack of real friendship. Single sex dorms are a first step to addressing the problem, by contributing to the reduction of two major obstacles. But needed still are positive steps that encourage the practices of friendship.