7 Changes That Happen In Men’s Brains After They Have A Kid

Your brain doesn't stay the same over the course of your whole life, it changes as you do. So you might not be too surprised to find out that a major life event like having a kid can cause some big-time brain changes. Plus, just about every other part of your life changes when you have a kid, so why not your brain too? While you might think that only women's brains are affected by having a kid, that's not actually true. There are also some fascinating changes that happen in men's brains after they have a kid, according to science. These changes range from hormone levels rising and falling, to regions of gray matter actually expanding or shrinking.

Men's brains, like women's brains, even start this changing process before the baby is actually born. Once the baby is born, however, there are even more changes coming. The changes are designed to address the new roles that men need to fill in order to take care of the baby and make sure it's safe and its needs are met. Plus, researchers have found that the more time dads spend with their kids, the more of these brain changes they're affected by. Just conceiving a baby isn't enough to make these changes occur, but spending time around their pregnant partner and connecting with their baby allows for their brains to change in ways necessary to successfully navigate this new life challenge.


Testosterone Decreases

Before the baby is even born, a man's brain will start changing to adjust to his role as a father. In an opinion piece she wrote for CNN, Dr. Louann Brizendine, a clinical professor of psychiatry and author of The Female Brain and The Male Brain, wrote that when a man's partner becomes pregnant, she starts to release pheromones which cause the man's testosterone production to decrease by about 30 percent.


Prolactin Increases

The pheromones that his partner produces also cause prolactin levels to rise. This hormone helps men hear babies cry more easily — which, as Brizendine noted in the aforementioned article, some men have trouble doing before their partners become pregnant — and generally be more alert.


Prefrontal Cortex Gets Thicker

A 2014 paper published in Social Neuroscience concluded that the lateral prefrontal cortex in dads gets thicker. While more research is needed, this is the part of the brain that aids in decision-making, as Wired reported, so it makes sense that it'd be affected by a life change that will require a man to make many significant decisions.


Cortisol Spikes

Cortisol, the stress hormone, spikes after a man becomes a dad, just as it does in women who become moms. In a piece for Greater Good Magazine, Jeremy Adam Smith, the author of The Daddy Shift, wrote that the cortisol spike, as well as other hormone changes, help clue dads in to their baby's needs. It's important, because babies aren't able to communicate what they need on their own, so parents have to be able to decipher these needs on their own and these hormonal changes help them do just that.


Anterior Cingulate Cortex Gets Thicker

Just as the prefrontal cortex gets larger, so too does the anterior cingulate cortex. This part of the brain is in charge of processing emotions, as Wired reported in the previously-mentioned article, so, again, it's understandable that it might change at a time when a man is going through a major life change like becoming a dad.


Oxytocin Rises

Oxytocin, like other hormones, also rises in men when they become fathers. "Alterations like this have a positive — calming, affectionate, tactile and communicative — effect on both men and women," Dr. Philip E. Stieg, founder and chair of the Weill Cornell Medicine Brain and Spine Center and neurosurgeon-in-chief of Weill Cornell Medicine and New York-Presbyterian, said in an interview with Romper by email.


The Default Mode Network Shrinks

The aforementioned Wired article also reported that the 2014 study found that some parts of men's brains also shrink when they become dads. One such part of the brain is the "default mode network," which is named that way because it's the part of the brain that takes over when you withdraw, allowing your brain to continue to function without you having to think too much. The reason this is important for dads is because they're really not able to function that way anymore because, well, once you have a kid, staying alert becomes arguably more important than ever before.

Once you're a dad, all bets are off.

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