We’ve written earlier on research that suggests that oxytocin, the same hormone that is produced by mothers nursing their young or through sexual intercourse, plays a pivotal role in trust.
Recent research, published in Science last year and recently in PNAS indicates that oxytocin has a dark side. It doesn’t promote trust of everyone but strengthens “in group trust” and decreases “out group trust”.
Excerpt from NY Times article on the research:
With a new set of experiments in Tuesday’s issue of the Proceedings of the National Academy of Sciences, he has extended his study to ethnic attitudes, using Muslims and Germans as the out-groups for his subjects, Dutch college students.
These nationalities were chosen because of a 2005 poll that showed that 51 percent of Dutch citizens held unfavorable opinions about Muslims, and other surveys that Germans, although seen by the Dutch as less threatening, were nevertheless regarded as “aggressive, arrogant and cold.”
Well-socialized Dutch students might be unlikely to say anything derogatory about other groups. So one set of Dr. [Carsten] De Dreu’s experiments tapped into the unconscious mind by asking subjects simply to press a key when shown a pair of words. One word had either positive or negative connotations. The other was either a common Dutch first name like Peter, or an out-group name, like Markus or Helmut for the Germans, and Ahmad or Youssef for the Muslims.
What is measured is the length of time a subject takes to press a key. If both words have the same emotional value, the subject will press the key more quickly than if the emotional overtones conflict and the mind takes longer to reach a decision. Subjects who had sniffed a dose of oxytocin 40 minutes earlier were significantly more likely to favor the in-group, Dr. De Dreu reported.
In another set of experiments the Dutch students were given standard moral dilemmas in which a choice must be made about whether to help a person onto an overloaded lifeboat, thereby drowning the five already there, or saving five people in the path of a train by throwing a bystander onto the tracks.
In Dr. De Dreu’s experiments, the five people who might be saved were nameless, but the sacrificial victim had either a Dutch or a Muslim name. Subjects who had taken oxytocin were far more likely to sacrifice the Muhammads than the Maartens.
Dr. De Dreu believes that all group association spurs oxytocin, and it is no more likely to be formed through religious groups than through soccer associations, military units or PTA groups. This rise of oxytocin doesn’t occur in a vaccuum: Bruno B. Averbeck, an expert on brain emotional cognition at the National Institute of Mental Health, says that the brain weighs rational data against the emotional impact of oxytocin.
Read “Depth of the Kindness Hormone Appears to Know Some Bounds” (NY Times, Science Times, January 11, 2011, by Nicholas Wade)
Read “Oxytocin Promotes Human Ethnocentrism” (PNAS, Jan. 10, 2011) by Carsten K. W. De Dreu, Lindred L. Greer, Gerben A. Van Kleef, Shaul Shalvi and Michel J. J. Handgraaf.