The oxytocin hormone, known as the "love hormone," also affects antisocial behaviors, such as envy and gloating, Israeli researchers found.

Researchers at the University of Haifa said oxytocin, which affects behaviors such as trust, empathy and generosity, also affects opposite behaviors, such as jealousy and gloating. "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," Simone Shamay-Tsoory said in a statement.

The hormone is released in the body naturally during childbirth and when engaging in sexual relations.

The study, published in the journal Biological Psychiatry, found the study participants who inhaled the synthetic form of the hormone displayed higher levels of altruistic feelings compared with those who inhaled a placebo.

However, the study also found that participants who inhaled the hormone and played a game displayed higher levels of envy when the opponent won more money and of gloating when they were ahead, compared with those given the placebo.