The Human Brain Develops Throughout Life
Science once believed that the human brain stops developing after reaching a certain age. But the latest research shows this old view is wrong: the human brain keeps developing throughout life, even into old age. If a person finds knowledge fascinating and is willing to learn for a lifetime, his brain will never stop developing. Although some functions decline with age, the brain is an exception. Older scholars who remain sharp-minded bear this out: the economist Ronald Coase, the Chinese scholar Zhou Youguang, the chemist Professor Zheng Ji, and Yang Jiang (Qian Zhongshu's wife) were all over a hundred with nimble minds and sharp thinking.
For people with cranial nerve problems, this is the best news possible. It means they can recover brain function by mastering methods that promote brain development; in fact, many treatment concepts and methods in psychiatry revolve around this principle. Patients with epilepsy, depression, anxiety, schizophrenia, and many others whose central nervous system has been damaged by accidents (such as viral infection, tumor, or stroke) all have some degree of brain injury and will benefit from this research.
The brain contains a vast number of neurons — about 100 billion in each person's brain, more than a hundred times the total human population. These neurons can be activated by the outside world. For example, when we see someone laughing heartily, we involuntarily laugh along; the biological mechanism behind this is that the neurons in our brain responsible for laughter are activated under the influence of the other person's matching neurons. Or consider a devoted man who expresses his love to his beloved every day; although she does not love him at first, over time she is moved by his devotion and comes to love him in return. In fact, this is the love-related neurons in our brain being activated under the influence of the other person's loving behavior. Similarly, in reading and learning, the neurons in our brain are influenced by other people's neurons and learn to think as they do.
This is the principle by which our brain learns and develops — very simple, essentially imitation and repeated training. But when the brain reaches an advanced stage of development, it gains the ability to innovate; however, so-called innovation never arises from nowhere; it is always built on skills already learned.
Everyone is born with this ability to be influenced by others; our neurons are excellent at imitation. That is why square-dancing groups never lack participants, why cult leaders always have a host of followers, and why "charming" authors always capture the hearts of large readerships. Epigenetic changes can also be reversed: methylated neural stem cells may, under various influences, undergo demethylation. That is why neuroblastoma in children frequently produces cases that astonish the medical community — spontaneous remission. The reason is that during development, children's neurons activate certain biological mechanisms that promote nervous system development and normalize it. The experiences of these children who self-heal from cancer offer much inspiration to cancer researchers like me; I too am exploring how to switch on a cancer patient's self-healing mechanism.
So it is with our emotions. Emotions are actually chemical reactions driven by a series of neurotransmitters in the brain. Happiness, for example, is brought about by neurotransmitters such as dopamine, serotonin, and phenethylamine. If our brain lacks these neurotransmitters, we feel melancholy. But the human brain, through long evolution, is highly developed and has prepared more than one pathway to happiness. If you lack serotonin and cannot feel happy, but suddenly have a great deal of phenethylamine in your serum, you will become happy under its influence. It is like starting Plan B when Plan A fails.
The human body is fascinating; the same thing happens in the immune system, which has several checkpoints. When one checkpoint fails, others take over. Our gene pool contains enough weapons to meet the various challenges we face in survival, because our evolutionary history on Earth as living organisms is very long; many of the life mechanisms developed during evolution are actually optimal solutions for surviving in nature.
The term phenethylamine may sound too technical to many people; in fact, it is the neurotransmitter released when two lovers are in love. Interesting, isn't it? We often say that our lover is the medicine that heals us; and indeed there is a biological basis to this saying.
Love can promote brain development. If our hypothalamus, amygdala, and hippocampus are troubled — stuck in anxiety, depression, or fear, with the hippocampus loaded with negative emotions — this region of the brain seems paralyzed. But when someone loves us, the love-related neurons in our brain are activated, our serum fills with phenethylamine, and our happy Plan B kicks in. It quickly clears the unpleasant records in our hippocampus, repairs the damaged parts of our hypothalamus and amygdala, and restores our vitality. This region of the brain develops rapidly, and we are healed.
That is why people often forget the pain of a breakup after a new romance and regain their vitality. Some depressed patients, after a soul-deep love with a well-matched partner, find that both brains develop together and depression is cured without treatment. Bad romance works the opposite way, of course; a bad intimate relationship is even one of the chief causes of depression.
Emotionally unstable people sometimes need mood stabilizers like lithium carbonate to steady themselves, but when they meet a truly good confidant and lover, they can stabilize their emotions without lithium. Because the person they love, in giving love, understanding, care, and compassion, activates the relevant neurons in their brain, and the emotional instability is resolved.
Many people after a breakup constantly say, "From now on I will love myself." In fact, this statement is semantically wrong. Love is a matter between two people; love does not exist in isolation. Like force, love is an interaction; alone, a person is only protecting themselves, not loving. We can only say we protect ourselves; saying we love ourselves is meaningless. Our love is not demonstrated by caring for ourselves; rather, when someone who loves us cares for us, we feel love, and then we return love to them, and they feel it in turn. Biologically, self-caring does not produce phenethylamine and lacks the nature of love. You cannot be swept off your feet or deeply moved by your own care for yourself, but you can be when a lover loves you.
Not only can romantic love promote brain development; parent-child relationships can too. There is a strong bond between mother and child, and it goes without saying that promoting each other's brain development is natural. Even a father gets a great opportunity for brain development after the child is born. Spending time with the child every day trains both the child's brain and the father's. Fathers who have raised children differ from those who have not in many ways; most are more emotionally stable and more intellectually developed, because interacting with a child requires thinking.
Interestingly, we often say childhood is the happiest time, and this is indeed true. The worlds of children and adults are completely different; older people with childlike personalities who love playing with children tend to share the innocence of children. I am such a person; at any age I prefer playing with children. My younger cousins, my nephews and nieces, even the neighbors' children, all gather around to romp with me as soon as I come home. So I have greater ability to relate to minors and less skill with adults, which makes my own mentality more childlike.
Laozi in the Daodejing most highly valued returning to simplicity, advocating that people return to a childlike state. If we grasp the laws by which the brain operates, this goal is easily achieved: just play with children more. The neurons in children's brains can activate matching neurons in ours; as we play with children, their joyful emotions easily infect us. Over time, we naturally become an old child at heart — one of my personal secrets to staying happy.
Besides interacting with our own kind, we can also promote brain development through reading and learning. Language and writing are original inventions of human beings as high-level intelligent animals; from language and writing we can also receive the information necessary for brain development, which promotes its growth. That is why the more one learns, the smarter one becomes. On the question of IQ, innate genes determine only half; the other half is determined by the learning environment acquired after birth.