Study Reveals Brain Chemistry Behind Human Bonding

BOSTON — Bonding between a mother and her newborn child may come naturally, but a new study reveals how human brain chemistry is hard at work for both babies at parents during loving interactions.

The study, published in the journal Proceedings of the National Academy of Sciencesset out to determine exactly how human bonding takes place. It was known that parents and children do connect through an act called “synchrony,” where they mirror each other’s movements. But researchers at Massachusetts General Hospital wanted to take these findings a step further and find out how that works from a neurological level.

The team, led by Northeastern University’s distinguished psychology professor Lisa Feldman Barrett, confirmed that the neurotransmitter dopamine plays a big part in the process. They studied 19 mothers and their babies and looked at the reward centers in their brains as they interacted with one another. To monitor the brain’s activity, the researchers relied on a machine capable of performing an fMRI and a PET scan at the same time.

mother, newborn baby
A new study explains how brain chemistry and the neurotransmitter dopamine plays a role in how mothers bond with their babies.

Before the brain scans, each mother was filmed interacting with her baby at home in order to determine the level of synchrony between the two. The babies were also filmed playing by themselves.

During the brain scans, each mother was shown the video footage of her baby playing, as well as a video of an unfamiliar baby playing. Mothers with higher levels of synchrony were found to have increased levels dopamine in their brain when watching the videos of their own children.

“Animal studies have shown the role of dopamine in bonding but this was the first scientific evidence that it is involved in human bonding,” Barrett explains in a university release. “That suggests that other animal research in this area could be directly applied to humans as well.”

Dopamine controls the reward center of the brain and is the chemical that drives addiction and cravings. The researchers realized that the chemical played a significant role in how mothers and babies respond to one another and ultimately guides the strength of human bonds.

“We found that social affiliation is a potent stimulator of dopamine. This link implies that strong social relationships have the potential to improve your outcome if you have a disease, such as depression, where dopamine is compromised,” explains Barrett. “We already know that people deal with illness better when they have a strong social network. What our study suggests is that caring for others, not just receiving caring, may have the ability to increase your dopamine levels.”

The researchers admitted that the findings were cautionary at best, but also reiterated that the “parents’ ability to keep their infants cared for leads to optimal brain development, which over the years results in better adult health and greater productivity.”