The Male Brain Explained: How Hormones Shape Masculine Behavior, Bonding, and Growth
“.....idea that the male is the default-model human still deeply pervades our culture. The male is considered simple; the female, complex.” ― Louann Brizendine
We wanted to share because learning this information about the male brain has helped both of us foster better relationships, improve communication, and promote personal growth and well-being. The majority of the information comes from a book recommended by, Dr. Pat Allen, “The Male Brain,” by Louann Brizendine. This book is a neuroscientist’s account of the interplay between hormones and brain development that shapes the formation and growth of male brains and behavior. Based on decades of research, it proclaims that the roots of many masculine stereotypes can be seen in neurobiology, and that hormones shape the male brain and outlook for a lifetime. In this article, we will provide an overview of the male brain’s structure and function, the development of male cognition, the impact of testosterone on the brain, and the effects of gender and culture on male behavior. We will begin with how a male brain is born.
From eight weeks of gestation onward, three hormones have a large impact on the development of the male brain. The first is testosterone, whose rises and drops affect everything from male brain development to sex drive to hair growth. The second is vasopressin, the male bonding hormone. It influences things like his mate-guarding behaviors and bonding. The third has a complex name and a complex function. Called Müllerian inhibiting substance, it builds many of the circuits in the male brain that are associated with traditional masculinity. It shrinks any remnants of female structures in the developing embryo to grow a male body. And it creates the neural connections for things like muscular action, exploratory behavior, and competitive aggression.
This hormone trio, along with a few other helpers, grows a brain that ends up looking significantly different from the female brain. The amygdala, the part of the brain that handles fight or flight reactions to threats, becomes larger and contains more neurons in the male brain. Their circuits for defending territory are larger, too, while their communication circuits and memory centers have far fewer connections than female brains.
The male brain is bathed in high levels of these hormones until birth and beyond, and they shape his behavior during those early days. For the first year of life, his testosterone levels are on par with an adult man’s. This inhibits brain circuits for recognizing facial expressions, which are smaller than his female-brain counterparts.
By seven months, he can recognize facial expressions of anger or fear in adults, but by twelve months his sensitivity to them plummets. With an immunity to signs of danger or warning, and a neurological drive to explore and track motion, it can challenge even the most attentive caregiver to keep up and keep him safe. Without brain structures in place to put on the emotional brakes, he’ll likely be easily worked up and harder to soothe. His outbursts will last longer, and he’ll make less eye contact during these emotional exchanges.
At the end of the first year, his hormone levels decrease as the male brain becomes a juvenile. For the next decade, he’ll most likely have low, steady hormone levels like his female-brained counterparts. But his brain has been completely structured under the hormonal influence, and his on-the-go, rough-and-tumble impulses will continue through boyhood.
Boyhood is as close as the male brain will be to his female-brained counterparts since the first eight weeks as an embryo. Behaviorally, however, the distinct characteristics between male and female brains make for some striking differences. His play will likely look far different from his female-brained peers. While female brains are practicing their verbal communication, consensus-building, and social skills on the playground, male brains have a different focus.
With more structures and neurons controlling muscular activity and spatial awareness, pecking order and hierarchy, his play often looks chaotic and rough. Racing, competing, and gaming satisfy his need for continual challenges and tests. Winning is everything and it gives his brain a hit of dopamine, the body’s reward chemical, when he does.
He’ll also have a hard time putting the brakes on playing with his own penis. Partly, this is the influence of those high levels of testosterone in infancy. While his peers with female brains are getting dopamine rewards from communicating and connecting, he gets a massive rush from the pleasure centers of his brain when playing with his penis because those circuits are far stronger. If a young female brain experiences dopamine withdrawal when separated from friends, the same is true for young boys when they can’t touch themselves. The effects can be as strong as withdrawals from drugs like cocaine. At puberty, some of this will change, but for male-brained teens, it means much of it intensifies. As testosterone levels soar, it brings on everything from acne and body hair to uncontrollable erections.
His lack of rewards from the communication centers of his brain continue, but his aggression and need to challenge authority dials up. His physical growth quickens at this time, too, and his need for independence skyrockets. Many who interact with a male-brained teen find him bored, uncommunicative, and resistant. He isn’t acting bored; he is bored. His brain doesn’t light up with communication, but with action, challenge, and risk. With his prefrontal cortex still forming, he doesn’t have full control over his behavior, either. The prefrontal cortex understands cause and effect. So he literally can’t exactly grasp the consequences of skipping homework in favor of video games, or what might happen if he misses the trampoline while jumping off the roof. The increase in testosterone also kicks off sexual drive. Given the sheer amount of neurons in the male brain dedicated to sexuality, this new obsession will impact the male brain for decades to come.
Young boys get dopamine rushes from playing with their penises, but teen and adult male brains get far more. Testosterone has driven this sexuality reward system, and when sexuality awakens in puberty, it can feel like a force of nature.That’s in large part because it is. The hypothalamus, the structure deep in the brain that kicked off puberty, is conducting a hormonal symphony in the maturing male brain. His hypothalamus drives his mate-seeking behavior, and when the male brain notices a potential sexual partner in the room, it lights up like a Christmas tree. All those motion-tracking and environmental exploration circuits developed in infancy and childhood now scan the environment for potential partners. In mate-seeking mode, the teen and adult male brain can seem to have only one focus. Biologically speaking, this isn’t far off.
When mate-pursuing mode gives way to the mated mind, this vasopressin reward system transforms the brain once again. When the male brain first has sex, a part of the hypothalamus memorizes his partner’s smell, their touch, and their sounds and imprints them deep in the brain. The huge dopamine reward he gets at the same time means he associates this experience with immense pleasure. If his brain has high levels of vasopressin, and receptors to absorb it, this can form the male brain into a monogamous mind. He bonds intimately, reinforced through vasopressin and dopamine by touching, cuddling, and sex. (Note: Checkout our substacks on vasopressin for more details pertaining to this hormone.)
When the mated male mind learns that he will become a father, yet another powerful transformation begins. It might be the first time he sees his child on an ultrasound, or not until he holds his newborn, but his bonding hormone vasopressin soars in these moments and forges a deep bond. Many male brains evolve as a pregnancy progresses and have parallel emotional, physical, and hormonal shifts. That’s because their testosterone levels begin to drop off sharply, while their levels of a hormone called prolactin rise.
Fathers who have a more intimate role in pregnancy, childbirth, and fatherhood have larger drops in testosterone levels. This may be because hormonal communications between partners via smells, touch, and kissing ramp up signals of looming parenthood and both brains restructure in preparation. Dad’s motion tracking and action-tuned brain centers evolve with this hormone change to care for active children and be on guard for their safety. His vasopressin and dopamine rushes are triggered by holding and playing with his child. Fathers are especially attentive during alone time with their kids, and these interactions make kids more self-confident. So the dad brain confers a powerful evolutionary advantage to their children.
From early adulthood, testosterone levels in the male brain have been slowly decreasing with age. They may have dropped more with fatherhood, or traced a slow arc downward. His levels of vasopressin have also dropped. With less testosterone, the aging male brain is becoming more like that of the postmenopausal female brain. He may be more sensitive to cuddling and touch. He may also begin to respond to oxytocin, and he becomes kinder, gentler, and far less prone to anger. He becomes more confident about expressing a full range of emotions, too. The circuits for defensiveness and anger that thrived in high testosterone now shrink, and the lion mellows. He may become less territorial, no longer quick to fight. He cares less for hierarchies, too, and about his place in the pecking order. His brain weighs the costs of victory at any price, and cares less about what others think of him. No longer obsessed with his own dopamine-fueled sexual pleasure, this brain is more tuned into the pleasure of his partner. He might even get as much pleasure from his partner’s orgasm at this age as he does from his own. Without a partner or close bonds, feelings of loneliness intensify. This isn’t character weakness but another biological imperative. Aging male brains thrive with the connected bonds that their female counterparts have nurtured since childhood. Staying connected to others actually improves physical health, lessens depression, and prolongs his life.
Male brains and bodies begin forming at eight weeks through a surge of the hormone testosterone. Throughout life, just a few hormones shape the neural structures and biological drives of the male brain. From his active boyhood through potential fatherhood, his levels of testosterone, vasopressin, and prolactin mold both his body and his intimate bonding. A drop in these hormones by old age brings him closer to the postmenopausal female brain, helping him forge the bonds that keep him happier and healthier.
For additional information on the male brain, you can purchase the Zenchronicity class on this topic. In this one hour class, Megan will provide even more fascinating facts about the male brain. All of these insights should help provide insights into the male experience so you can be better equipped to empathize with male loved ones, colleagues, and clients, fostering more effective relationships and a more harmonious society.
