Warm and Fuzzy Oxytocin Has Its Limits

Oxytocin is a hormone most commonly associated with the close feelings of trust and companionship that lovers and family members feel. But the chemical may have a dark side: new research shows there are limits to the affection it can stimulate, the New York Times reports. Experiments by University of Amsterdam researchers employed familiar psychological methods for assessing subconscious negative feelings and the willingness of subjects to sacrifice a single person for the greater good.

The names used in the experiments were typical German or Muslim names—"out" groups for the Dutch students who participated in the study. A quick sniff of oxytocin, and the Dutch students were both more subconsciously apprehensive about "out" group names, and all to ready to throw Ahmed or Helmut in front a moving train in order to save 5 people's lives—suggesting that oxytocin's positive vibes stop shortly at the border of one's own sense of community.
(More oxytocin stories.)