A Dutch study highlighted in last Tuesday's New York Times, claims to have shown that their country's bad attitude toward Muslims and Germans is fueled by the brain hormone, oxytocin. The researchers concluded this after having Dutch men inhale oxytocin or a placebo before completing a series of studies designed to measure social attraction and empathy. The subjects' button-pushing response time was measured when presented with classic Dutch, German, or Arabic names that were paired with either positive or negative words. Next they had to select which of the names they would save or sacrifice in hypothetical (and wildly improbable) life or death scenarios. When the subjects inhaled oxytocin, they quickly chose Dutch names linked with positive words and were most likely to sacrifice a Muslim or German named-character in favor of saving Dutch-named people. The researchers concluded that oxytocin supports "in-group" fidelity and that their study, "calls into question the view of oxytocin as an indiscriminant love drug or cuddle chemical."
The thing is that no one has ever seriously suggested oxytocin's social agenda was "indiscriminant." Decades of animal and human studies found that oxytocin does indeed promote "selective" social bonds like those that make a mother ewe care only for her lamb, or those that inspire male and female prairie voles to mate for life. Such exclusive loyalties can make very good evolutionary sense, but a lot of the time a more inclusive social attitude is beneficial and oxytocin has been shown to be helpful there as well. With the aid of oxytocin we can overcome the fear of novelty that might cause us to automatically reject unfamiliar people. This primal tolerance allows a new mother to instantly accept her newborn "stranger" as her own. It also encourages babies to seek and accept nurturance from other caregivers, urges us to mate with "outsiders" rather than kin, and is central to our ability to create the wide range of friendships and alliances--beyond our clans and even beyond our species--that made human civilization possible.
Oxytocin manages to encourage this wide range of social flexibility by making us very good at evaluating verbal and non-verbal social signals. With the help of oxytocin, our brain's fear and stress circuitry are suppressed enough for us to perceive the glint of friendship in an eye or tone of voice that encourages social approach. And when our encounters prove beneficial, it releases even more oxytocin in our brains tripping the reward circuitry which will help us remember the faces of those we can trust, while urging us to connect with them again. This particular kind of memory and learning is called "social recognition" and under natural circumstances where adequate social stimuli are provided, it can support the oxytocin feedback system that creates a sense of trust and kinship far beyond tribe, nationality, or species.
The Dutch study appears to refute this, but they look at oxytocin's behavior divorced from its social milieu. The subjects made their social preferences based only on people's printed names. These abstract representations merely suggest nationality and gender and fail to provide the sort of non-verbal social information oxytocin is so good at parsing. So what did a nose full of oxytocin do with such limited social information? It may simply have heightened the Dutch men's sense of recognition and attraction to names most similar to their own. If the experiments had asked their subjects to respond to pictures of faces of Dutch, German, and Arab making a variety of friendly and unfriendly expressions and found that oxytocin-treated Dutch men still favored frowning Dutch faces over smiling foreign ones, I think that would make a stronger case that oxytocin, is the "not-our-kind" hormone. It would also be surprising because other studies have found that inhaling oxytocin improves our first opinion of strangers-even when the unfamiliar faces were paired with electric shock.
The researchers also propose that this study shows that oxytocin played an important evolutionary role in the "emergence of intergroup conflict and violence." But I would point out that the bulk of oxytocin research finds it is not an agent of aggression and territoriality. In fact, it's capable of making the sorts of social distinctions that help us override reflexive anti-social behavior--otherwise known as prejudice. And human history tells us somewhere, deep in our brains, cooperation trumped competition time and time again. It was this ability to discern social intention in those "outside the clan" that gave us the new social kinships called "neighbors," "citizens," "livestock," and "pets," that made us the most successful social mammal on the planet. While our impressive frontal lobes helped, we still owe much of our social grace to oxytocin.
Made For Each Other, The Biology of the Human-Animal Bond (DaCapo, 2009).