A recent study by child psychiatrists and neuroscientists at Washington University School of Medicine in St Louis, published online in the Proceedings of the National Academy of Sciences Early Edition, states that children whose mothers showed them love and affection from the very beginning have brains with a larger hippocampus, which is a key part of the brain involved with memory, stress response, and learning.

The hippocampus is a very important element of the brain. It is part of the limbic system and is largely involved in grouping together information from short term memory to long term, as well as aiding in spatial navigation. When the body is stressed, the brain triggers the autonomic nervous system, which releases stress hormones to help the body deal with stress. The hippocampus is the main area of the brain that helps with this response. Leading the research is author Joan L. Luby, MD, professor of child psychiatry. She says:

This study validates something that seems to be intuitive, which is just how important nurturing parents are to creating adaptive human beings. I think the public health implications suggest that we should pay more attention to parents’ nurturing, and we should do what we can as a society to foster these skills because clearly nurturing has a very, very big impact on later development.

The researchers used brain imaging technology on children aged 7 to 10 years, who had been involved in a previous study of preschool depression, which was conducted by Ludy and team about 10 years prior to the new study. The previous study examined 3 to 6 year olds who were showing signs and symptoms of depression, a different type of psychiatric distress, or were completely mentally healthy with no signs of psychiatric problems at all.

During this first study, the kids were watched and videotaped while their parents, in most cases, the mother, were busy completing an unfinished project and the children had been told to wait to open an appealing present, which can be “stressful” on children. The amount of support, help, and understanding the parent was able to give to their children was examined by people who had no idea what type of mental health state the child was in, and knew nothing about the parents.

Luby states:

“It’s very objective. Whether a parent was considered a nurturer was not based on that parent’s own self-assessment. Rather, it was based on their behavior and the extent to which they nurtured their child under challenging conditions.”

This particular study did not focus on child-parent interaction at home, or give them daunting and challenging exercises, however, other studies have conducted research using similar ways of observing whether or not a parent is a nurturer when dealing with their child. In this latest study, the authors performed brain scans on 92 of the children, who had been involved in the previous study and showed symptoms of depression, or were completely mentally healthy when they were younger. These scans showed that the kids who did not show symptoms of depression and had been nurtured earlier in life possessed a hippocampus close to 10% bigger than the ones whose mothers did not act as nurturing. Luby explains:

“For years studies have underscored the importance of an early, nurturing environment for good, healthy outcomes for children. But most of those studies have looked at psychosocial factors or school performances.

This study, to my knowledge, is the first that actually shows an anatomical change in the brain, which really provides validation for the very large body of early childhood development literature that had been highlighting the important of early parenting and nurturing. Having a hippocampus that’s almost 10 percent larger just provides concrete evidence of nurturing’s powerful effect.

There have been studies on adults showing the same results, Luby says, so this may have been expected. However, she was surprised to know that nurturing parents had such a dramatic impact on mentally healthy kids. She says, “The fact that the researchers found a larger hippocampus in the healthy children who were nurtured is striking, because the hippocampus is such an important part of the brain structure.” The study mostly looked at children’s interaction with their biological mothers. However, the researchers are sure the outcome would be the same when analyzing the nurturing tendencies of anyone acting as the main parenting figure in the children’s lives. For example, adoptive parents, biological fathers, or grandparents. Luby concludes:

“Studies in rats have shown that maternal nurturance, specifically in the form of licking, produces changed in genes that then produce changes in the receptors that increase the size of the hippocampus.

That phenomenon has been replicated in primates, but it hasn’t really been clear whether the same thing happens in humans. Our study suggests a clear link between nurturing and the size of the hippocampus. Parenys should be taught how to nurture and support their children. Those are very important elements in healthy development.”

Wrtten By Christine Kearney