Mind & Brain How Dads Develop When men morph into fathers, they experience a neural revival that benefits their children By Brian Mossop THIS IS A PREVIEW. Buy this digital issue or subscribe to access the full article. Already a subscriber or purchased this issue? Sign In Photoillustration by Aaron Goodman Last year I met my four-month-old nephew, Landon, for the first time. During the weekend I spent visiting him in San Diego, my inner science nerd often got the best of me. I would find myself probing my nephew’s foot reflexes and offering unsolicited explanations for why his toes curled this way or that, only to be met by my wife’s disapproving looks and the new parents’ blank stares. Soon enough I dropped the shoptalk in favor of baby talk. Having spent my postdoctoral career in neuroscience, I have seen how important early experiences are for a baby animal’s health. In the first few days after birth, babies’ brains are like sponges soaking up their sensory environment. What to me seemed like inconsequential sights or smells had markedly different impacts on the impressionable newborns, shaping their brains as they tried to make sense of the unfamiliar world around them. But as astonishing as a baby’s brain is, on this family visit what struck me was the redevelopment of my 26-year-old brother-in-law. THIS IS A PREVIEW. Buy this digital issue or subscribe to access the full article. Already a subscriber or purchased this issue? Sign In Buy Digital Issue $7.95 Add To Cart Browse all subscription options! Subscribe ADVERTISEMENT Scientific American is a trademark of Scientific American, Inc., used with permission © 2015 Scientific American, a Division of Nature America, Inc. All Rights Reserved.