It’s widely known that soon after child birth it is important to establish a strong emotional bond between the mother and their child by putting the infant on the mother’s chest. Part of how this happens is due to a neurohormone called Oxytocin. Oxytocin is released by the infant and the caregiver responds with a feeling of well-being. The same thing happens when you hold an infant which often makes a person feel sleepy. I can attest to this when I’ve held my nieces and nephews.

Oxytocin is a peptide that is released during child birth, breast feeding, and orgasm. It is something that helps bond people together. It helps us build trust with our significant others. Two important studies shed light on how this happens. The first is a study that investigated how likely people would give money to people they didn’t know and the second involves a little rodent called the Prairie Vole.

The money lending study was cleverly designed. Participants were part of teams. As a reward for doing simple tasks they were given small monetary rewards. They were instructed that they could share part of their reward with their team members if they wanted to. People who were given a shot of oxytocin prior to the study distributed bigger rewards to their team mates than those who were not given the oxtytocin. This suggests that oxytocin influences whether we will trust someone.

Next is the Prairie Vole study. Prairie voles stay with their partners for life after they mate. They raise their pups together in seemingly marital bliss. This is quite rare among mammals. Only about 5% of mammals show monogomous biparental behavior. When researchers injected the prairie voles with chemicals that blocked their oxytocin receptors, the prairie voles no longer formed lasting Pair Bonds. A relative of the prairie vole, the meadow vole, does not form pair bonds with their mates. When researchers injected meadow voles with oxytocin, the meadow voles formed lasting attachments with female partners.

What is the difference between the two kinds of voles? Dopamine receptors, which are involved with pleasure and reward, overlap oxytocin receptors in the prairie vole. This suggests that the prairie vole finds it rewarding to form a pair bond after oxytocin is released. The meadow vole, on the other hand, does not have the same overlap between their dopamine and oxytocin receptors. So, the meadow vole does not experience the pleasant feelings associated with oxytocin and thus does not form pair bonds.

Humans, too, are hardwired to form pair bonds but we are more complex than voles. We learn how to interact with people by watching our parents, siblings, and friends. We can learn to suppress our emotions if we see other people ignore their feelings. Suppressing our emotions causes the oxytocin-dopamine system not to work as it was intended. Of course, we can’t form a life Lasting Pair bond with each of our lovers, but disconnecting ourselves from our emotions continuously can have a detrimental effect on our ability to form Lasting Pair Bonds later. This sort of thing can be unlearned over time if we make the effort. So you see, oxytocin not only bonds a mother to their child, it helps us build trust and lasting attachments with the people we care about the most.