According to psychologists, taking paternity leave from work is beneficial for new fathers, as it enables them to develop profound parenting instincts.
"Spending engaged time with your new baby is a rare opportunity for long-term success in fatherhood," an article in the Harvard Business Review said. "This short-term time investment has the potential to pay a lifelong dividend in dad instincts."
The authors said previous research showed that motherhood is not as instinctual as many believe, and that new moms and dads need "parental instinct brain training" to learn how best to care for their infants.
Almost two-thirds of countries around the world have legislation mandating statutory periods of paid paternity leave. In most US states, new fathers have the option of up to 12 weeks off work — but without pay.
One study looked into changes to the "fathering brain" among new dads, comparing one group in Spain with those in California.
Darby Saxbe, a professor of psychology at the University of Southern California, and his colleague Sofia Cárdenas said the transition into parenthood was a key window of opportunity for "neuroplasticity", the ability to learn from experience.
That brain elasticity is at its peak in newborn children, who learn rapidly through both mimicry and trial-and-error. But as pathways between neurons are cemented by learning, the brains potential to create more hardwired circuits decreases.
"Fathers are made, not born," they said. "Time with infants is a key ingredient in building the fathering brain."
Psychologists believe changes occur in the paternal brain, prompted by signals from the newborn child which cement the father-baby bond.
"No one is born with this magic ability to fall into the role easily," said healthcare journalist Chelsea Conaboy, author of Mother Brain: How Neuroscience is Rewriting the Story of Parenthood. "But we need to do the work of fully engaging because that is the thing that’s going to drive the neurobiological changes to give them the tools that they need to build over the long term."