Becoming a dad can shrink a man’s brain

A new study suggests that becoming a parent changes the structure of a person’s brain. But don’t panic – it’s not necessarily a bad thing!

28 November 2022

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By Mariusz Bogacki, Researcher and Science Communicator, Edinburgh

Pregnancy and parenthood are a life altering experience for both parents. Yet, while studying the psychological and physical effects of having a baby for women has long been a subject for many researchers, the effects on men have often been overlooked. However, a new study suggests that becoming a father also comes with some physical consequences for men – and their brains in particular.

A recent study published in Cerebral Cortex Journal has found that even without physically experiencing pregnancy, men’s brain undergoes a transformation when they become a parent. The change relates to a longitudinal grey matter cortical volume reduction. In plain English this simply means that a certain part of the brain shrinks following the realisation of becoming a father. The reduction was found in an area of the brain known as ‘default mode network’, which is believed to be associated with parental acceptance and warmth.

This is not necessarily a bad thing. In fact, this readjustment can help new fathers improve the connection with their new-borns, making it more powerful and efficient. This is precisely what happens with women’s brains. Post birth brain refinements are associated with greater neutral responses to a child and therefore stronger child-parent attachment.

It is worth mentioning that this study is only the first of its kind, and conducted on a relatively small sample of heterosexual men in Spain and California (USA). More research is needed in order to analyse post-birth brain readjustments in men in different cultural settings, as well as in non-heterosexual relationships.

Even still, the results open up possibilities for a new line of research, contributing to a better understanding of parenthood. Understanding the inner workings of a human brain post-pregnancy can be helpful in identifying and treating postpartum depression, which while less frequently, also affects men. Equally, if not more importantly, such studies will also benefit studying the child’s wellbeing and childhood more broadly.

Parenthood can be a complex, demanding and wonderful experience. This study shows that it is also rewarding – although perhaps in ways that some might not have expected. Once again it turns out that less, sometimes means more.