Inside the dad brain: Science of fatherhood and change
Fatherhood does not just change a man’s routine; it changes his brain. Beneath the sleepless nights, diaper changes, school runs, and endless questions, something quieter but more profound is happening.
Little is known about the physiological and behavioural changes that expectant fathers undergo before the birth of their babies.
In a first-ever study demonstrating hormonal changes in men, published in 2000 by two Canadian scholars, Katherine Wynne-Edwards and Anne Storey, demonstrated hormone concentrations and responses to infant stimuli in expectant and new fathers living with their partners.
According to the researchers,the study found that men experienced significant pre-, peri-, or postnatal changes in each of the three hormones measured, with patterns of change paralleling those found in women.
“Our results suggest that hormonal reactivity to social stimuli is also an important component of stage and individual differences in hormone-behaviour dynamics, although these changes have not been the focus of as much research as the absolute hormone concentrations,” the research read in part.
The Science inside Dad brain
The researchers obtained two blood samples from couples at one of four times before or after the birth of their babies.
After the first sample, the couples were exposed to auditory, visual, and olfactory cues from newborn infants, which was a test of situational reactivity.
The results showed that men and women had similar stage-specific differences in hormone levels, including higher concentrations of prolactin and cortisol in the period just before the births and lower postnatal concentrations of sex steroids (testosterone or estradiol).
Men with more pregnancy (couvade) symptoms and men who were most affected by the infant reactivity test had higher prolactin levels and greater post-test reduction in testosterone.
As part of the research, hormone concentrations were correlated between partners. This pattern of hormonal change in men and other paternal mammals, and its absence in nonpaternal species, suggests that hormones may play a role in priming males to provide care for young.
From the studies, I came to a simple conclusion, which is: fatherhood changes men in ways that echo the ways motherhood transforms women.
The more involved a father is with their baby’s care, the deeper this transition becomes.
These shifts in our endocrine and neural system show that the nurturing father is not a modern aberration, but a deeply rooted biological trait.
