The hormone best known for its role in inducing labor may influence our ability to bond with others, according to researchers at the University of California, San Francisco.
In a preliminary study, the hormone oxytocin was shown to be associated with the ability to maintain healthy interpersonal relationships and healthy psychological boundaries with other people. The study appears in the July issue of Psychiatry.
"This is one of the first looks into the biological basis for human attachment and bonding," said Rebecca Turner, PhD, UCSF adjunct assistant professor of psychiatry and lead author of the study. "Our study indicates that oxytocin may be mediating emotional experiences in close relationships."
The study builds upon previous knowledge of the important role oxytocin plays in the reproductive life of mammals. The hormone facilitates nest building and pup retrieval in rats, acceptance of offspring in sheep, and the formation of adult pair-bonds in prairie voles. In humans, oxytocin stimulates milk ejection during lactation, uterine contraction during birth, and is released during sexual orgasm in both men and women.
Turner and her colleagues tested the idea that oxytocin is released in response to intense emotional states in addition to physical cues. Twenty-six non-lactating women between the ages of 23 and 35 were asked to recall and re-experience a past relationship event that caused them to feel a positive emotion, such as love or infatuation, and a negative emotion, such as loss or abandonment. Because massage done on rats had previously been shown to influence oxytocin levels, the participants also received a 15-minute Swedish massage of the neck and shoulders. Blood samples were taken before, during, and after each of the three events to measure baseline oxytocin levels in the bloodstream and any change.
The results, on average, were of borderline significance - relaxation massage
caused oxytocin levels to rise slightly and
Contact: Rebecca Sladek Nowlis
University of California - San Francisco