Oxytocin is best known as the “love hormone” for its ability to trigger empathy, generosity and trust. But after testing 56 volunteers, Shamay-Tsoory found that there was a fine line between love and jealousy – and that oxytocin could also bring out antisocial behaviors. Her study was published in the latest issue of Biological Psychiatry.

“Subsequent to these findings, we assume that the hormone is an overall trigger for social sentiments. When the person’s association is positive, oxytocin bolsters pro-social behaviors; when the association is negative, the hormone increases negative sentiments,” she explained.