It is a life changing experience to become a parent. As a society, motherly instincts and the way that parenthood changes a mother’s career trajectory are commonly discussed, but scientists and sociologists have just recently discovered some surprising ways that becoming a father changes a man inside and out.

Changes To The Bank Account

Many studies that shown that, historically, having a baby can be a strong predictor for a woman making less money throughout her life regardless of the career field she was in prior to becoming pregnant. When a father has a baby, the exact opposite effect happens. The results of a wage study conducted in New York show that regardless of industry or starting position, fathers make more money than childless men.

Some sociologists believe parenthood has a different effect on mothers and fathers because mothers often take some time off of work during pregnancy and some stop working altogether after the baby is born. Aside from the societal gender norms that a man should be a breadwinner and provider, men have a greater impetus to make more money after having children. A child is a new addition to the household that brings on new bills. Whether the mother stays home to care for the child or the family decides to pay for daycare, the child’s care will take a toll on family finances, and many fathers seek out higher paying positions to account for the extra expense.

Aside from affecting their career trajectories, fatherhood also has a proven impact on a man’s mental makeup.

Changes In The Bloodstream

Oxytocin is a hormone that mothers naturally release when they breastfeed. This neurotransmitter makes the mother love her child and want to bond with her baby, and, in the female body, it causes the production of breastmilk. Although fathers do not produce breast milk, men with children less than two years old have been found to have unusually high levels of oxytocin in their blood. Prolactin and estrogen levels are also higher in fathers than men without children. In addition to an increase in the hormones usually associated with females, the male hormone testosterone decreases in new fathers. Scientists believe that these changes naturally occur to decrease the father’s aggression and increase their loving, nurturing feelings toward their newborn child.

In many cases, fathers willingly start to spend less time with their friends in order to spend more time with their family. This happens because fathers have a hormonal need to parent, nurture, and love. Especially in a situation where the father works full-time outside of the home, fathers are highly inclined to choose to trade more of their free time for family time.

Changes In The Brain

Fatherhood literally changes the hardwiring of a man’s brain. Similar studies have shown that new fathers have an innate neurological response to young children. Fathers and mothers have the exact same response to pictures or videos of their own children.

Technically speaking, fathers become naturally smarter than men without children. In both humans and animals, fathers of newborn children spontaneously grow new neurons in their brains. Some scientists hypothesize that, at least for humans, it is connected to the overwhelming euphoria of having a child. A father’s world suddenly changes. Within a single day, a father gains a little human that relies on him for care, training, and protection. That realization causes the father’s brain to grow more neurons.

In addition to general growth in the number of neurons, there are specific sections of the brain that grow while others shrink. Different parts of the brain control different types of emotions. Certain parts of a father’s emotional makeup are heightened by fatherhood and other parts become suppressed.  

The prefrontal cortex is the part of the brain that makes fathers seem smarter. Fathers have bigger prefrontal cortexes than the average man without children. A person with a bigger prefrontal cortex has a greater ability to remember information. A larger prefrontal cortex also correlates to having better problem-solving skills.  

New fathers have been shown to experience growth in the gray matter of the amygdala. The amygdala is a part of the brain that helps to control emotions. As a man builds space in his heart for his child, the brain grows to build capacity for processing the sudden flood of emotions. This greater capacity for emotions helps the father to nurture and love the child just as a mother does.

A father’s orbitofrontal cortex swells in size when a child is first born, but it gradually decreases as the child ages. This cortex is responsible for feelings of anxiety and stress. Fathers of newborns have a high level of anxiety, but this stress decreases as the child grows older. That type of stress is referred to as eustress. Eustress happens in response to positive major life changes. It’s scary and confusing to be a new father. There’s a new little life relying on the father, and the father doesn’t know how to care for that life yet. As the father becomes more comfortable in his role, his stress levels naturally decrease.

There’s no question about it. When a man becomes a father, his life changes forever. He forms an unbreakable bond with a new little life. He has a strong chance of making more money than he ever has before. He also will experience hormonal and neurological changes that will physically and emotionally equip him for the most important job he’ll ever have – being a father.