Y:Time to go again to the A Moment of Science mailbag. A listener writes:
Dear AMOS,
My sister has a five-month-old girl, and when I'm playing with her and she smiles, my heart just melts. What's the science behind why a baby's smile is so heart warming?
D:Great question. The answer is that it's not so much the heart as it is the brain. And if you think your sister's baby makes you feel all gooey inside, imagine what the baby's smile does for your sister!
Y:That's right. Scientists at the Baylor College of Medicine in Texas have found that when a mother sees her baby smile, it lights up reward centers in the mom's brain.
D:How do they know this?
Y:Well, the researchers put twenty-eight moms in functional MRI scanners and studied how their brains responded when the moms viewed pictures of their infants and other babies smiling, looking sad, and with neutral expressions. And when the moms saw their own babies smiling, important reward regions of their brains lit up. Actually, it's the same part of the brain that's been associated with drug addiction.
D:So for a mom, seeing her baby smile is like being on drugs?
Y:Sort of--you could call it a natural high. When her baby smiles, the mom's brain appears to release dopamine--a chemical involved with feelings of happiness and joy, and the same one that's triggered by some narcotics.
D:But this happens only with smiles, right? When the moms saw pictures of their babies looking sad or neutral, their brains didn't react as strongly.
Y:Yep. It seems there's something particularly powerful about a baby's smile.
