Previous studies have shown that the oxytocin hormone has a positive effect on positive feelings. The hormone is released in the body naturally during childbirth and when engaging in sexual relations. Participants in an experiment who inhaled the synthetic form of the hormone displayed higher levels of altruistic feelings, and it is supposed that the hormone plays an important role in the formation of relationships between people.
However, in earlier studies carried out by other investigators with rodents, it was found that the hormone is also related to higher levels of aggression. Therefore, it was decided to examine whether the hormone also affects negative social sentiments. The present study, which was published in the journal Biological Psychiatry, included 56 participants.
From: "The narrow line between love and jealousy."