‘Dad brain’ is real. It’s reshaping our understanding of fatherhood.
New fathers may be losing brain volume, and that could be a good thing.
That was one of the striking findings shared by Darby Saxbe, professor of psychology at the USC Dornsife College of Letters, Arts and Sciences during a recent Dornsife Dialogues event.
The discussion centered on her new book, Dad Brain: The New Science of Fatherhood and How It Shapes Men’s Lives, which debuts in June. Saxbe’s research shows that men’s brains change after the birth of a child, particularly in areas linked to empathy and social understanding.
Speaking with USC Dornsife Dean James Bullock, Saxbe described her studies tracking first-time dads from pregnancy through early infancy. Brain scans revealed reductions in each father’s gray matter after their child’s birth. Rather than signaling decline, she said, the changes likely reflect the brain becoming more efficient, like editing a film to focus on the essential story.
Her book builds on that finding to challenge a long-standing assumption that caregiving is something only mothers are naturally wired to do. Instead, Saxbe argues, fatherhood is highly adaptable, especially if fathers are committed to the role. “The more dads wanted to engage in parenting and were invested in it, the more the brain changed,” Saxbe said.
The conversation also explored the emotional realities of new parenthood. More involved fathers reported higher stress, fatigue and even symptoms of depression, emphasizing that deeper engagement can bring both rewards and strain during the transition.
Access to paid paternity leave, Saxbe noted, was linked to lower stress for fathers and reduced depression among mothers, suggesting policy plays a key role in shaping family health.
Saxbe’s book goes beyond neuroscience, examining how fatherhood influences relationships, careers and identity. She frames modern fatherhood as a model of “pro-social masculinity,” centered on caregiving, patience and connection. Her research is part of a larger shift in our understanding of what it means to be a dad, and how much the new role of parent changes men themselves.