Biological fathers experience a spike in the hormone prolactin to enhance nurturing behavior

Paternal care is driven by significant hormonal shifts, notably a spike in prolactin levels that occurs in men following the birth of their child. Prolactin, traditionally associated with milk production in women, serves to increase alertness and responsiveness in fathers. Observations show that fathers with high prolactin levels are twice as likely to engage in 'play facilitation' with their six-month-old infants compared to those with lower levels.