Will A Man’s Brain Change After He Becomes a Father? 


For most men, transitioning into fatherhood is a big deal, signifying one of the most —if not the most— important phases of their lives. Although significant physical and emotional alterations do not accompany this entry into fatherhood —as it happens throughout the pregnancy, childbirth, and motherhood experiences of women— men do experience some changes in their brain’s makeup.

Extensive research into the connection between a father and his newborn has revealed that a man’s brain undergoes several changes in the first weeks of fatherhood. 

During a 2014 study, researchers studied the brain activity of 89 new parents while they watched videos of their children. This study observed mothers who were the primary caregivers, fathers who worked outside the home but helped with childcare, and even homosexual fathers who took care of the child without the help of a female. 

Among the three groups, the study revealed that the networks of the brain typically associated with emotional processing and social understanding were highly active in the participants. One key takeaway from this study was that the men who raised the children without the aid of a woman showed almost identical emotional processing signals in the brain that appears with a female caregiver. 

Further, Elizabeth Gould —a psychologist at Princeton University— conducted a series with her colleagues, which indicated a significant increase in estrogen, oxytocin, prolactin, and glucocorticoids in both human and animal fathers. In a 2001 study by the Department of Biology at Queen’s University, scientists discovered that the male testosterone—known as the male sex hormone— and the cortisol hormone (or the stress hormone) begin to dip drastically during the first weeks of fatherhood. 

It should also be noted that estradiol, the predominant form of estrogen —the female sex hormone— further plays a pivotal role in nurturing behaviors and male sexual function. Therefore, when this form of estrogen is present within the male system, it promotes more behavioral attitudes that aim to nurture the child. 

Finally, prolactin —popularly known as the “Mom hormone”— also surges in new fathers. According to a 2002 study, it was discovered that there is a lowered testosterone level and correlating heightened prolactin levels in the male brain. This has been linked to new fathers’ emotional responses when their infants cry. 


In conclusion, becoming a father causes significant structural and functional changes in a man’s brain. Additionally, this ensures they can become good father figures in the child’s life throughout their early years.