SAN ANTONIO — Oxytocin, a hormone with a rosy reputation for getting people to love, trust and generally make nice with one another, can get down and dirty, according to evidence presented on January 28 at the annual meeting of the Society for Personality and Social Psychology.
This brain-altering substance apparently amplifies whatever social proclivities a person already possesses, whether positive or negative, says psychologist Jennifer Bartz of Mount Sinai School of Medicine in New York City.
Previous work has shown that a nasal blast of the hormone encourages a usually trusting person to become more trusting (SN Online: 5/21/08), but now Bartz and her colleagues find that it also makes a highly suspicious person more uncooperative and hostile than ever.
“Oxytocin does not simply make everyone feel more secure, trusting and prosocial,” Bartz says.
These new results raise concerns about plans by some researchers to administer oxytocin to people with autism and other psychiatric conditions that include social difficulties, she adds.
Her team studied 14 people diagnosed with borderline personality disorder and 13 volunteers with no psychiatric conditions. Symptoms of borderline personality disorder include severe insecurity about relationships, fears of abandonment and constant, needy reassurance-seeking from partners.
Borderline personality disorder usually occurs in women, but Bartz’s sample included four men. Her group of healthy participants included seven men.
Members of each group played a computer game with an experimenter posing as a research volunteer. In each of three rounds, volunteers had to predict whether their partner would cooperate with them so that each player could make $6 or if the partner would leave the game in order to claim $4 alone.
Volunteers who suspected the partner of bad intent could leave the game early and claim $4 for themselves.
Borderline personality players of both sexes left the game early far more often after receiving an oxytocin nasal spray than after whiffing a placebo spray. Inhaling the hormone prodded their already high levels of hostile suspicion and depleted minimal reserves of trust, Bartz suggests.