“A son’s brain is different from his mother’s.”
Even after he died and came back to life, his mother couldn't understand the great adventure of a son's mind!

There are countless stories of sons causing trouble: making a mess of the house in the blink of an eye, jumping around at random and breaking limbs, getting distracted and completely forgetting things when asked to run errands, and getting so absorbed in games that they don't do what they should be doing.
Every time that happens, mothers raising sons say this.
“I just can’t understand why he’s doing that!”

Mothers scold, comfort, and annoy their sons, and eventually end up blaming themselves, asking, "What did I do wrong? Did I raise my son wrong?"
Although they love their son very much, they do not have accurate knowledge of his nature, so they misunderstand his actions, create conflicts, and even experience difficulties in communication.


This book is a revised edition of "The Son's Brain," which has been a long-term bestseller in child education for many years. It is the latest work by Professor Kwak Yun-jeong, who is considered one of the best parenting mentors in Korea, solving parents' concerns through various broadcasts and lectures, including EBS Documentary Prime.
Professor Kwak applies brain science, which has been actively researched over the past several decades, to parenting. He clearly and easily explains what is happening in a son's brain and why he behaves strangely, so that a mother, a woman, can accurately understand and accept her son, a man.
It also suggests age-appropriate parenting, conversation, and study methods tailored to the brain development stage, and provides solutions to key questions Korean parents have while raising their sons, thereby helping both parents and sons develop a free and happy relationship.


Truly understanding someone begins with knowing exactly what their desires and thoughts are.
If parents can understand and accept the objective characteristics of their son's brain, it will not only enable smooth communication but also greatly contribute to their son's positive development.

Because a son is a different gender than his female mother, it can feel like he has no way of understanding what she is thinking.
In the case of a daughter, the scope of empathy expands as she recalls her own childhood and realizes, "Oh, I thought that too when I was her age."
However, because my son is a boy, it is difficult for me as a mother to understand, feel confused about, and sympathize with my son's behavior.
It is true that men and women grow differently emotionally, just as they are biologically different.
For various reasons, mothers raising sons feel trapped in a maze of parental and maternal roles as their sons grow up.
Fortunately, there is a hint here that may help us understand a little bit about our son.
This is because the recent research results that we have learned through the advancement of science and technology to observe and study the brain are telling us stories that can be of some help to parents, especially mothers, in understanding their sons.
You might find it boring, saying, "What a complicated brain!" But understanding what we're born with can make your relationship with your son much easier.

--- pp.20-21

One of the common findings of many scientists interested in male and female brain development is that from the time of conception, boys develop the right brain and girls the left brain.
This can be seen in the thickness of the cerebral cortex, which means that a thicker cerebral cortex has a larger volume due to the formation of many synapses between brain cells.
The part of the cerebral cortex that is large in volume and has densely packed synapses demonstrates considerable ability. It is said that the cerebral cortex on the right side of the brain is thicker in sons, and on the left side of the brain in daughters.
The right brain is associated with artistic imagination, plays a role in understanding things in an integrated and comprehensive manner, and is good at processing information about spatial and three-dimensional objects.
The left brain is associated with the ability to handle language fluently and is characterized by analytical and logical thinking.
In particular, the son's right brain is significantly developed in spatial perception and spatial reasoning abilities such as mechanics, geography, map reading, and measurement.
Since we can't measure the abilities of an unborn fetus, we compare the abilities of children. Of the millions of participants in the U.S. Geography Fair, 45 times more boys than girls make it to the finals.
--- pp.53-54

As a son grows up, the reason a mother and her son clash is because the characteristics of his brain become more evident.
It is really difficult for a son to infer and guess his mother's feelings and thoughts.
Think about it.
I'm struggling to focus on my own feelings, so how can I possibly look into and understand my mother's heart? I know she's upset because she tells me, but it's difficult for me, as a son, to truly understand her specific feelings and emotions.
And above all, because the left brain is not very powerful, if the mother does not speak very loudly and strongly, the son will not be able to pay attention to what she is saying.
It's a really strange thing for a mother to do.
I am aware of my son's emotional state, why he is upset, and even that something feels off.
What a mother needs at this time is not nagging, but understanding her son's brain.
Rather than trying to fix the characteristics and abilities of your son's brain, it is important to understand and acknowledge them.

--- pp.74-75

There are two reasons why a son's brain and a daughter's brain are so distinctly different. The first is the difference in the corpus callosum.
As I mentioned earlier, the corpus callosum is a bundle of nerve cells that acts as a passageway connecting the right and left brains, and acts as a bridge for exchanging information between the right and left brains.
The leading researcher who discovered the difference in brain volume between sons and daughters is Dr. Laurie Allen, a brain scientist at UCLA.
Dr. Allen used X-rays to examine the brain structures of men and women, and found that the male corpus callosum was only about a third as large as the female corpus callosum.
For this reason, sons tend to develop reading skills later than daughters.
The left brain is responsible for recognizing and understanding the symbols called Hangul, while the right brain is responsible for composing Hangul symbols into sounds and matching them.
These two roles combine to produce reading ability, but sons with smaller corpus callosums are slower than daughters at processing and exchanging information between the left and right brains, so they are slower at reading.
--- pp.86-87

Since men have evolved to hunt since primitive times, their brains also show developmental characteristics suited to hunting.
So, they react more immediately to the sounds of animals or objects than to the soft voices of people, and their vision develops more than their hearing because they have to continuously search for prey.
This is also why the voices of mothers raising sons continue to grow louder.
Normally, a son's brain has a hard time focusing on auditory stimuli, so he doesn't react much unless the sound is quite loud.
Accurately understanding the tendencies and characteristics of your son's brain is essential to guiding and directing his studies.

--- pp.210-211

Over time, the son grows from a baby, to a boy, to a teenager, to a young man, and then to an adult.
Although it is a natural and expected stage, the most dramatic change occurs during adolescence.
Your teenage son has grown so much that it feels like he is no longer your child.
But unfortunately, although he is physically an adult, his brain is still immature and cannot control itself, and he occasionally releases testosterone, which makes his parents suffer.
During childhood, testosterone is secreted about once or twice a day, but during puberty, it increases rapidly to about five to seven times a day.
In addition, the amount secreted at one time also increases.
So, the blood testosterone concentration of adolescent boys is said to be ten times higher than that of children.
The biggest reason why a son who was always well-behaved loses his temper over trivial things, starts swearing, and swings his fists is the increase in testosterone levels.

--- pp.241-242

The term "middle school syndrome" has become popular lately.
It is an expression representing the peak of puberty, which is characterized by emotional changes and rebellious behavior.
Perhaps that's why teenagers in puberty sometimes act as if they have a free pass when they misbehave, saying, "Well, I'm old enough to do that."
The reason these thoughts and actions are dangerous is because the brain remembers patterns of thought and action.
To put it more precisely, it means that because the brain cells in the prefrontal cortex, which is the center of emotional regulation, do not have the opportunity to learn this, there is a high possibility that the ability to regulate emotions will decline in later life.
The ability to regulate and control emotions is something that can be developed.
The important point is that there is an appropriate and effective time to develop and educate these abilities, and this is the critical period.
Unfortunately, areas of the brain that miss critical periods are difficult to recover.
Since the ability to regulate and control emotions is governed by the prefrontal cortex, which develops the latest, it can be said that adolescence, a time of the most emotional changes, is paradoxically a crucial time to practice regulating and controlling emotions.

--- p.279