What could sexual habits, maternal instinct, socializing and contraction of the uterus have in common? Oxytocin. Though very modest in length – barely 9 amino acids long – the number of major functions in which oxytocin is involved, is almost indecent.

Oxytocin was discovered almost a century ago. It is produced in the brain and has long known to be a hormone that favors contraction of the uterus during childbirth as well as the secretion of milk whilst breast-feeding. Indeed, hospitals still make use of oxytocin to stimulate lazy uteri during labor. It also seems to be involved in reproductive behaviors such as a female’s sexual appetite, fidelity and maternal instinct. Furthermore, its role in social cohesion such as the recognition of a familiar partner have led scientists to form the hypothesis that defects in the hormone’s metabolism could lead to psychiatric illnesses associated with relational deficiencies such as autism.

How about oxytocin and males? Oxytocin is also involved in male reproductive behavior in instances as critical as the regulation of erections or the progression of sperm during ejaculation. And male fidelity? It is vasopressin – oxytocin’s cousin – which fulfills that role.

Besides parturition, lactation, social cohesion and an individual’s sexual habits and drive, what other role could oxytocin possibly have? Tranquillizing properties. The positive benefits of a massage are unknown to no one and guess what can be detected after a good massage? Oxytocin. So despite a very modest length, here we have a protein which participates in our general well-being. No less.