RACHEL MARTIN, HOST:
Have you ever seen someone nuzzle a baby and exclaim: you are so cute. I could just eat you up. As a mother, I have to admit I have uttered some variation of this phrase when cuddling my own baby. I have gone so far as to nibble on my child's ear or his foot. Johannes Frasnelli of the University of Montreal says there is a biological reason we talk about wanting to devour our kids. He joins us now from his home in Montreal. Welcome to the program.
JOHANNES FRASNELLI: Hello.
MARTIN: You have done a study on this phenomenon. And you say it all has to do with how babies smell?
FRASNELLI: Yes. We think body odor of the babies has a very big influence on how we perceive a baby and how we develop our relationship to the babies.
MARTIN: Walk us through how you figured this out.
FRASNELLI: Yes. So, we collected the body odors of some newborn babies in the first two nights of their life. We left them wear some pajamas and then we presented the odors from these pajamas to the mothers while they were in a MRI scanner so we could look at what's going on in their brain if they smelled the odor of those babies.
MARTIN: And what happens when these women were smelling these baby smells? They reacted positively?
FRASNELLI: So, we did not only test the mothers, we also tested women that were not mothers. But in both groups of women, we saw an activation of the reward centers of the brain. So, these centers of the brain are activated usually if you are able to eat something when you're very hungry, or if you are a drug user and you finally get your drugs, or also by the body odors of those newborn babies.
MARTIN: It triggers this desire to, oh God, I just can't say eat the baby. Like, it's just too weird.
FRASNELLI: No, of course. No, no, no. Of course, I don't think that we have the desire to eat the baby or anything close to that. I think it's just how- I mean, you being a mother, you know it yourself - you're living your life as a couple, everything is going fine and all of a sudden you have this little human being in your life that is actually, if you look at it from an objective point of view, actually pretty annoying. Everything the baby does is sleeping, crying, and other than that you have to change the diapers. Still, most of the parents say this is the most beautiful thing that ever happened to me. And so how does this work? And we think the sense of smell helps us to understand the mechanisms that make this very strong attachment.
MARTIN: Johannes, do you have any kids?
FRASNELLI: I do not have my own child, but I live with my wife, who has a nine-year-old son.
MARTIN: So, have you had personal experience with this?
FRASNELLI: Yes. And I remember my mother told me that babies have a very distinct smell and this smell reminded her of chicken soup. So, I don't know if it's chicken soup but it's - everybody listening to us who has a baby at home could just go and smell and see what they smell like.
MARTIN: Johannes Frasnelli is a postdoctoral fellow at the University of Montreal. He joined us from his home there. Thanks so much for talking with us.
FRASNELLI: Thank you very much. Bye-bye.
MARTIN: This is NPR News. Transcript provided by NPR, Copyright NPR.