A study showed Oxytocin's effects on human social behavior are not clear. Some studies reveal significant positive changes, yet others show none at all. In many animals, from rodents to non-human primates, it's a different story: Oxytocin has been proven to increase positive social behaviors and attention paid to others, and reduce negative social behaviors like threats and vigilance. The hormones flatten group hierarchy, resulting in dominant monkeys becoming more relaxed and subordinate monkeys becoming more confident. The study was published in Scientific Reports

To understand what happens during spontaneous, naturally occurring interactions following inhalation and injection of both oxytocin and a similar neuropeptide, vasopressin. This holds even when just one of a pair receives oxytocin or vasopressin, indicating some sort of non-verbal communication between the animals.

This society, which is often described as despotic, hierarchical, and regulated by aggression and submission, becomes more egalitarian. Everyone is a little nicer to everyone else. The work, the first of its kind, involved giving one macaque oxytocin, vasopressin, or saline via inhalation or injection, then pairing him seven times, six with different monkeys and once with an empty chair, in a random order. 

However, they could interact and could see, hear, and smell each other. The researchers recorded a five-minute exchange; then two separate observers scored the behavior, frame by frame. Seven macaques participated in the inhalation work, and seven participated in the injection work. Social dominance in monkeys is a really big deal. They live and breathe for it. But here, the curve got flattened.

Vasopressin leads to the same outcome as oxytocin, which complicates the picture of how such hormones work. Receptors for the two are located in different parts of the brain and can bind to both hormones. By injecting small amounts of the hormones into a brain area that only contains vasopressin receptors, they found that oxytocin appeared to be binding to vasopressin receptors to change behavior.

By digging deep into these hormones and their underlying mechanisms could potentially lead to breakthroughs in therapeutic treatments for social disorders such as autism and schizophrenia and bipolar disorder. It may also help children who have had pituitary tumors removed, a procedure that can damage the hypothalamus and lead to ravenous overeating for reasons still unknown. Because oxytocin regulates feeding and social behavior.

They anticipate that for these kids, there is a whole set of underlying social problems that people are not dialed into because they are focused on the fact that the kids cannot stop eating. They are trying to determine whether when they treat them for overeating, that also improves social functions.

Their reaction to oxytocin and vasopressin also seems to mirror that of people. Despite such incremental advancements in knowledge, there's still much to understand. They have a lot more to learn about how, when, and in what manner we use these peptide hormones to treat various problems.