While recent studies show that pregnancy and childbirth positively alter the brain chemistry of mothers, could parenting have a similar impact on men?
The 2005 book The Mommy Brain documented research by Craig Kinsley and Kelly Lambert on female rats who were either pregnant or recent mothers, showing that motherhood sharpened their senses and increased their motivation and resilience. Susan Kuchinskas reports for Miller-McCune that this same team is now concentrating on fathers. Their research on mice, along with similar studies on monkeys and humans, suggests that fatherhood chemically alters men to make them better fathers.
“Loving a woman and fathering her children changes a man’s body and brain in ways that make him more canny and resourceful,” Kuchinskas writes, “while improving his ability to handle stress. At the same time, living with the woman he loves alters a man’s hormones and neurochemistry to make him a better mate.”
Examples in nature include: the California deer mouse, who stays around the home after mating to groom and look after his kids; the male marmoset, whose hormones cause him to gain weight along with his mate during pregnancy; and, the “highly monogamous” titi monkey, who mates for life and allows his offspring to cling to his body.
In humans, studies have found that married men have lower levels of the hormone testosterone, while new fathers exhibit higher levels of prolactin. Both of these conditions positively influence a father’s parenting skills by increasing his sympathy and motivation to help his offspring.
Interestingly, a study by the Wisconsin National Primate Research Center suggests that lower testosterone could actually be triggered by a newborn baby’s smell. Scientists at the center separated marmoset fathers from their families and then exposed them to scent from their babies’ genitals. Within 20 minutes, their testosterone levels dropped.