rewrite this title Recent studies show fathers’ brains change after bringing home a new baby

NPR’s Ayesha Rascoe talks to Washington Post journalist Richard Sima about how fathers’ brains change after bringing home a new baby.

AYESHA RASCOE, HOST:

There’s lots of evidence out there that mothers’ brains change and adapt during pregnancy and after childbirth. Now recent studies show that something similar happens in fathers’ brains after they’ve had a child. Richard Sima is a neuroscientist turned science journalist. He writes The Washington Post’s Brain Matters column and joins me now to explain. Before we get started, I hear you are a new father. Happy Father’s Day.

RICHARD SIMA: (Laughter) Thank you. And it’s great to be here.

RASCOE: So break this down for me. Like, how does the brain change once someone becomes a father?

SIMA: Yeah. As you mentioned, it’s very similar to what happens in a mother’s brain. We also have some shrinkage of the brain, but don’t worry. Shrinkage is not bad in this scenario because it’s actually a way of our brains adapting and sculpting out what connections are needed. The shrinkage, researchers find, happen in these mentalizing regions of the brain, which help us really connect with and figure out what another person is thinking and feeling and wanting. And that’s kind of what you want with a newborn. You’re like, what is this new little human? What do they need from me right now? And this shrinkage is associated with people being able to adapt to parenthood, to fatherhood better. Fathers who have more shrinkage in these areas tend to enjoy their infant more. They engage with the infant more. They feel less stressed.

RASCOE: Are there factors that determine the amount of change a father’s brain undergoes?

SIMA: Yeah. So what’s fascinating is that the amount of involvement with really being active as a father is associated with the amount of change. And we don’t know which way that direction of causation is. But it does seem like part of it is, like, the experience of being that parent is sculpting the brain. There’s studies looking at different cultures. Like, one culture doesn’t have as much hands-on childcare from the father, and another culture is much more hands-on. And there’s more changes in the more hands-on culture.

RASCOE: The research also notes some fascinating things about fathers’ hormonal changes. Can you explain that? What’s going on there?

SIMA: Yeah. So there’s a lot of great studies that looked at fathers before their child was born and up to a few months afterwards, and there was a huge change in their testosterone levels. We might think of testosterone as this very manly thing, and fatherhood is very conventionally masculine, but fatherhood is actually associated with lower levels of testosterone. And at the same time, there’s increases in prolactin, which is what we know is important for milk production but also found in men.

RASCOE: And what ultimately does this research reveal about the experience of parenthood? Did you find out anything that has kind of helped shape your new fatherhood experience?

SIMA: Yeah. It’s, I think, really pointing to just how dramatically parenthood can change any parent. And that sort of explains why when my daughter was born, it’s like, wow. Like, I understand now why people say, yeah, you fall in love so deeply and so quickly. And it makes sense that, like, wow. I’m having all these hormonal changes as well. Not as much as my wife, maybe. I’m having these brain changes, and they’re all really preparing us to really engage with this new human and try to be a good caregiver. You know, at the same time, the child is also having their brain changes. So we’re sort of doing this together as a family, trying to figure out the world and each other together.

RASCOE: That’s Washington Post journalist Richard Sima. Thank you so much for joining us.

SIMA: Thank you so much.

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