http://www.scientificamerican.com/article.cfm?id=a-love-hate-relationshipA Love-Hate Relationship?: "Feel-Good" Oxytocin May Have a Dark Side
The hormone promotes warm social feelings but can also promote in-group favoritism and ethnocentrism, suggesting there is a lot we don't know yet about the "cuddle chemical"
By Charles Q. Choi | January 12, 2011 | 14
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Oxytocin is often thought of as a "love drug," and is linked with all kinds of feel-good emotions in people such as trust, empathy and generosity. Increasingly, however, scientists are finding that the
hormone has a dark side—and now researchers have discovered it also can promote ethnocentrism, potentially fueling xenophobia, prejudice and violence. Past studies have shown that oxytocin fosters social feelings—between mates, for example, or mother and child—which explains why this "cuddle chemical" might be linked with goody-goody behavior such as altruism. Social feelings, however, are not always positive ones, reasoned social psychologist Carsten de Dreu of the University of Amsterdam in the Netherlands. For instance,
ethnocentric people view their own group as better than others—they feel closer to their compatriots, but potentially at the expense of outsiders.In five experiments 280 male Dutch volunteers first inhaled a spray containing either oxytocin or a placebo. In the first two experiments participants hit one button if they saw a positive word such as "wonderful" or the name of a fellow Dutchman on the computer, such as Maarten; they pushed another key if they saw a negative word such as "awful" or a foreign name. These groupings were then reversed—the volunteers pushed one button if they saw a positive word or a foreign name, and the other if they saw a negative word or a domestic name. Arab names such as Ahmed were used in the first experiment and German ones such as Helmut in the second. The researchers found that in both cases, volunteers given oxytocin were faster at linking fellow Dutchmen with positive words. There was also significant evidence that Arabs were more often linked with negative words, and weaker signs that Germans were.
In a third experiment the scientists investigated the extent to which volunteers ascribed uniquely human emotions such as admiration or contempt to fellow countrymen or foreigners as opposed to more basic ones such as exhaustion and pleasure. Participants given oxytocin were significantly more likely to associate more human emotions with Netherlanders than with Arabs, although they were equally likely to associate positive and negative emotions to either group. In the last experiments volunteers were given the option to save the lives of five nameless people by sacrificing one other person. These lone individuals either had typical Dutch male names, or foreign ones—Arab names in the fourth experiment and German ones in the fifth. Participants given oxytocin sacrificed foreigners more often than fellow Dutchmen. This isn't because they mercilessly sacrificed more outsiders than volunteers given placebo did—rather, they protectively sacrificed fewer fellow Dutchmen. The net result is that oxytocin makes people prefer their own group over other groups "and thus sets the stage for prejudice and social discrimination," de Dreu says of findings detailed online January 10 in Proceedings of the National Academy of Sciences.
"Recent classes of theories explaining the role of oxytocin in social behavior have focused only on prosocial positive behaviors such as trust and generosity. However, oxytocin is also involved in maternal aggression and territoriality," says neuroscientist Simone Shamay-Tsoory at Haifa University in Mount Carmel, Israel, who did not take part in this study. "Administration of oxytocin may provoke a wide range of emotions and behaviors related to social behavior and parenting, such as trusting collaborators, feeling love and compassion as well as attacking potential intruders and competing with rivals."
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