MARY LOUISE KELLY, HOST:
OK, to some dad news now and new research about parenting toddlers. A study published in the journal Behavioral Neuroscience suggests that fathers' brains respond differently to their daughters than to their sons. NPR's Patti Neighmond reports.
PATTI NEIGHMOND, BYLINE: Researchers wanted to investigate fathers' biological reactions to their children. Fifty-two fathers were involved in the study. As an MRI scanned their brain, the dads looked at photos of their 1 to 2-year-old children - girls and boys - appearing happy, then sad, then sort of neutral. Jennifer Mascaro is a biological anthropologist with Emory University.
JENNIFER MASCARO: We found that fathers of daughters had a more robust neural response to their daughters' happy facial expressions.
NEIGHMONG: That response was measured by looking at how active neurons were in different sections of the brain.
MASCARO: And these were neural responses in regions of the brain that we know are important for things like reward and motivation and also in systems of the brain that we know are important for processing emotions.
NEIGHMONG: Researchers didn't ask dads why they might have responded with greater pleasure to their daughters' happy faces. Mascaro anticipated fathers of girls would be more responsive to all three facial expressions. But...
MASCARO: We actually found that the fathers of sons had a more robust, neural response to the neutral facial expressions. These sort of ambiguous facial expressions.
NEIGHMONG: Again Mascaro doesn't know why, but she says it's intriguing that the fathers who responded most to their sons' neutral expressions also engaged in more rough-and-tumble play, which research shows can encourage emotional awareness and even greater flexibility later in life.
(SOUNDBITE OF ARCHIVED RECORDING)
UNIDENTIFIED MAN #1: Look.
UNIDENTIFIED CHILD: (Laughter).
NEIGHMONG: This is a recording of a father in the study playing with his son. Mascaro has hundreds of hours of recordings like this. All 52 dads agreed to wear recording devices when interacting with their toddlers.
MASCARO: It doesn't show you when it's recording. And so it turns out people behave quite normally or naturally when they are wearing it.
NEIGHMONG: And that's exactly what Mascaro wanted, father, son or daughter interactions in their natural habitat. As expected, fathers talked to sons more about achievement, using words like proud, win, top and best. With daughters, there was more emotional connection, with dads using words like lonely, crying and sad - and, it turns out, singing.
(SOUNDBITE OF ARCHIVED RECORDING)
UNIDENTIFIED MAN #2: (Singing) Hooray, hooray, to the store we go today. We'll buy some chicken. We'll buy some fish. We'll buy some sausages (unintelligible) you wish.
NEIGHMONG: Researchers were surprised to find fathers also using sophisticated analytical words when talking with their daughters.
MASCARO: These are words like much, below, above.
NEIGHMONG: Words that can encourage sophisticated thinking and more complex discussions later in life. Mascaro points to research showing high schoolers who use more complex language do better in college. Patti Neighmond, NPR News.
(SOUNDBITE OF LYMBYC SYSTYM'S "IN TRANSIT") Transcript provided by NPR, Copyright NPR.