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Reading enriches people and sharing makes people happy. At the end of the article, a mind map is attached to help you sort out the essence of the context in the text. Welcome to read, you are one step closer to knowledge.
The book shared today is Born and Born.
Matt Ridley, PhD in Zoology, University of Oxford, worked for The Economist for 8 years and is a popular science writer. His works are mainly concentrated in two areas, one is economics and the other is genes.
"Born and Acquired" mainly discusses the interaction between nature and nurture, genes and the environment. The Economist magazine says there is an acquired dialectic in the book that provides an excellent perspective on the acquired debate.
< h1 class="pgc-h-arrow-right" data-track="110" >01, the apothecaryistic view</h1>
The authors cite numerous scientific studies to prove that human behavior is not entirely governed by genes, and that it cannot be arbitrarily shaped by acquired experience. The authors believe that human behavior is determined by the interaction between congenital and acquired nature, and most of the characteristics of human beings are jointly affected by congenital and acquired factors. Let's first understand one of these ideas, that human behavior is not affected by innate factors of genes.
1. Genes
One of the most important scientific discoveries of the 20th century was genetics. In the eyes of many people, genes represent destiny, a product of fatalism, which is innate, immutable, and constrains human behavior. Indeed, modern science has confirmed that genes have a major impact on human behavior and personality, and even many cultural phenomena in human society are affected by genes.
For example, love. Love is nothing more than the product of genes, the oxytocin released in the brain, and is not exclusive to humans.
There is an animal called the prairie vole, which is a rare model couple in the mammalian world. Prairie voles are very loyal to their partners, monogamous, they will look at each other with affection after mating, and after giving birth to a vole, they will take care of it together and bathe the vibra.
Scientists then discovered that this love between voles was actually a product of a gene, which is determined by oxytocin in the posterior lobe. If you inject the brain of the prairie voles with posterior leaf oxytocin, they will be more loving, but if you inject a potion that blocks the posterior leaf oxytocin, the prairie voles will immediately become "negative people" and no longer engage in monogamy.
This example of a prairie vole shows that the love between voles is largely genetically manipulated. Are humans like voles? From a genetic point of view, human love and vole love have a similar genetic basis. If you scan people in a relationship with a machine, they're producing hormones somewhere in their brain, and voles do the same.
Matt Ridley says love is closely related to posterior oxytocin. But the point is that even if your brain secretes oxytocin, it doesn't mean you're going to be in love, let alone when you're in love and who you're in love with. Genes bring you the ability to love, but that doesn't mean love is bound to happen. That is to say, the expression of genes requires conditions and will be affected by the external environment.
Another example is negative behavior such as abuse. In 2002, researchers surveyed more than 400 young men in New Zealand and found that those who had violent behavior had a gene called MAOA that was less active and not very like the average person. Does that mean that the low level of genetic activity necessarily leads to violent behavior? Not.
The researchers then found that if people with low MAOA gene activity have not been abused since childhood, then their violence is similar to that of ordinary men, and there is no difference. But if they have been abused, they are 4 times more likely to be involved in violence such as rape, robbery, assault, etc. than the average boy. This shows that although genes themselves have an impact on human behavior, these influences also require the participation of the external environment to play out.
2. Gene empowerment
These findings can prove that genes are not the masters of humans. Not only that, but in Matt Ridley's view, genes are governed by our behavior, our helpers and tools. Genes are designed for the outside world, and instead of restraining you or manipulating you, they give you more possibilities and give you the opportunity to choose.
For example, learning. Not only do humans learn, but so do animals. Some scientists did an experiment with fruit flies, they first gave the fruit flies a bad smell of gas, and then immediately gave the fruit fly a shock to the feet. After a few times, the fruit fly understood that as soon as it smelled strange, it meant that it was about to be shocked, so as soon as it smelled the strange smell, it would quickly fly away. It's a learning process.
So how is the process of memory and learning of fruit flies accomplished? Scientists have found that all animals and humans have the same gene, called the CREB gene. In the process of memory and learning, this gene will turn on and synthesize a protein called a reaction binding protein. This protein alters synapses between brain cells to achieve the function of memory and learning.
Of course, the learning process doesn't just involve this one gene. For example, scientists have found that the memory of learning something new and extracting the memories of what have been learned require different genes. The process of learning and memory involves at least 75 proteins, the product of 75 genes, that work together like a very sophisticated machine to serve our learning and memory.
In the process of learning, humans are using genes as tools to respond to the external environment. Matt Ridley believes that most of the genes are like this, designed for the acquired environment, and it is our helper. Sometimes humans also take the initiative to correct the effects of genes on themselves.
For example, studies have found that two twins who grew up together in the same environment have a greater difference in behavior than twins who grew up separately. Why? Because in the same environment, the twins will deliberately cultivate their differences with each other, for example, if one of them talks more, the other will tend to talk less, forming a different and complementary personality.
<h1 class="pgc-h-arrow-right" data-track="109" >02, the post-apocalyptic view</h1>
Then let's look at it from the perspective of the day after tomorrow, can we shape human nature at will. In the eyes of extreme acquired theorists, people have no instincts and are born with a blank piece of paper. Your character and behavior are entirely created by the acquired environment. As long as you train properly, you can become whatever I want you to be.
John Watson, the founder of the behavioral school of psychology, once declared, "Give me a dozen sound babies and let them grow up in the environment I set, and I can train them to be anybody, doctors, lawyers, artists, businessmen, thieves." ”
The general view of acquired theorists is that as long as we establish reward and punishment mechanisms through the guidance of the day after tomorrow, we can shape human nature and determine human behavior. Is this really the case?
A scientist named Harry Harlow did an experiment in which he put several small monkeys in cages, each with two models of mother monkeys, one cold mother monkey made of wire, and the other soft, mother monkey made of ragdolls. Among them, the mother of the snub-nosed monkey holds a bottle in her hand, and if the little monkey wants to drink milk, she must be close to the mother of the snub-nosed monkey. According to the acquired view, living beings are born without instincts, and their various behaviors are trained. As the saying goes, if there is milk, it is a mother, and since the bottle is in the hands of the mother of the snub-nosed monkey, the little monkey will definitely be close to the mother of the snub-nosed monkey.
But the results of Harlow's experiments were not. He found that the monkeys would only go to the mother of the snub-nosed monkey to drink a little when they wanted to drink milk, and the rest of the time they were willing to stay with the soft muppet monkey mother. This shows that the little monkey has an innate preference for soft monkey mothers. Harlow also took a photo of the little monkey wrapped around the muppet mother with its hind legs, and then leaned over to drink the milk from the iron snub-nosed monkey mother's hand, indicating that although the little monkey was not guided in any way, it would instinctively attach itself to the soft muppet monkey mother.
Later, scientists did similar experiments and found that the little monkeys were not only naturally more attached to the soft monkey mother, but also preferred the shaky, warm monkey mother. These experiments show that when the little monkey is born, it is not a blank piece of paper, but has some innate preferences.
This shows that living things are instinctive. So, can we, as John Watson said, transform living creatures as we please, by nurturing them, without caring about their instincts? The answer is, no. Let's look at another experiment.
There was a scientist named Susan Minica who also did a very famous experiment with monkeys. She found that if a monkey grew up in a laboratory from an early age, it would not be afraid of snakes. But if a monkey grows up naturally in the wild, it will be very frightened when it sees a snake. The reason for this is simple, because even if a wild monkey has never been bitten by a snake, it will learn the fear of snakes from the behavior of its mother or other partners. But the monkeys in the lab don't have a learning object, so they don't know how to be afraid of snakes.
Minica then conducted an experiment on videotapes. She first took a real video and showed it to the monkeys in the laboratory, and the picture in this video tape was the real reaction of the monkey mother to the snake, and she was particularly scared. After the monkeys read it, they were also particularly afraid of snakes. This shows that the monkey can fully understand the videotape and can easily learn the fear of snakes.
Minica then took a cut fake video and showed it to the monkeys in the lab. The picture in this videotape is of the mother monkey who is very scared after seeing an ordinary flower, which is of course a forgery. If, according to the acquired theorists, monkeys in the lab see mother monkeys afraid of flowers, they themselves develop a fear of flowers. But the actual experimental situation is that even after watching this videotape, the monkeys will not be afraid of flowers, they may just think that the monkey in the picture is not normal, and there is nothing to be afraid of flowers!
Since then, many scientists have used different methods and done many similar experiments, and the results are the same. This shows that it is not that we want the monkey to be afraid of anything and that it will be afraid of anything, and we cannot transform the monkey as we please. Fear of snakes is partly in the monkey's genes, but monkeys are not born with a fear of flowers, and if you want to go against the monkey's instincts to domesticate it, it is difficult to succeed.
In Matt Ridley's view, Harlow and Minica's experiment was so great that it was tantamount to declaring the bankruptcy of acquired determinism. We can't even modify animals at will, let alone transform humans with advanced intelligence.
Attachment to mothers, and fear, that they are born in genes, is easier to understand. But in fact, there are many phenomena that seem to have nothing to do with congenitality, but in fact, they will also be affected by innate genes and cannot be changed at will.
For example, political positions, it seems that it should be completely shaped by the educational and cultural environment of the day after tomorrow, but some experiments have found that they are also influenced by genes. For example, researchers have found that a pair of identical twins raised separately has a 69% correlation in their "right-wing tendencies", while there is no correlation between fraternal twins.
<h1 class="pgc-h-arrow-right" data-track="76" >03, innate and acquired interactions</h1>
How are human behaviors and traits influenced by innate and acquired interactions?
1. Weight
One study found that an identical twin, if they grew up in the same family, had an 80 percent weight correlation, and if they had grown up in different families, the weight correlation was still 72 percent, which was a little lower. But if you are a pair of fraternal twins who also grew up in the same family, the weight correlation is only 43%, which is even lower. As for the unrelated, adopted siblings, although they grew up in the same family, the weight correlation is only 1%, which is similar to none.
In this experiment, identical twins, genetically similar, grew up in different environments and had different eating habits, but their weight was still very similar. But people with very different genes, even if they grew up in the same environment, but the weight similarity is still low. Therefore, from this result, it can be clearly seen that a person's weight is mainly affected by innate genes and has little to do with acquired eating habits.
Does that mean that eating habits do not affect weight, and we can give up on ourselves and eat casually? Nor is it. Because the study just now can only show that even if everyone eats the same, some people are just a little fat, which is a genetic problem. But if we look at a person's specific weight fluctuations, then we can see the importance of eating habits, no matter what your genes are, as long as you eat more, you will definitely grow fatter.
Scientists have now found that the average weight of Americans has been increasing, although other countries may be similar. Is the increase in the average American weight genetically or by eating habits? As a group, the rate of genetic change is actually very slow, measured in tens of thousands of years or even longer. So in just a few generations, American genes will certainly not change much. Then the increase in average weight must be caused by acquired factors such as eating habits, which have nothing to do with genes.
As can be seen from this example, a person's weight is affected by the interaction of innate genes and the acquired environment. Genes determine the approximate range of your weight, but eating habits can also have an impact on your final weight.
2. IQ
Matt Ridley quotes a quote in the book that many professors believe that the reason why their children's IQ is high is because they are genetically good, but the reason why their students' IQ is high is because they teach well. Although this sentence is a slightly ironic joke, it is not without reason, because IQ and weight also have similarities, and are affected by the interaction of genes and environment.
There is a phenomenon that can reflect the importance of the acquired environment to IQ, called the "Flynn effect", which means that the IQ test score of humans will increase by 5 points every 10 years. The speed of human evolution is in the unit of ten thousand years, it is impossible to be so fast, so this phenomenon can only be due to the influence of the environment, because the standard of living and education of human beings will be better and better.
In the case of IQ, the interaction between successive days is more pronounced and more complex. Under different acquired conditions, genes and environments act differently and in different ways.
Another example is the former U.S. Secretary of State and Nobel Peace Prize laureate, Kissinger. Kissinger was born in Germany and fled to the United States with his parents, so Kissinger's English has a distinctly European accent. But Genge's younger brother, only 1 year younger than him, has no European accent at all, and speaks an authentic American accent. Why?
Matt Ridley says this is because human beings are born with the ability to learn languages, but which language to learn is affected by the acquired environment. And this influence is also very subtle: innate genes determine that people have a critical stage of learning language, in this stage, people's language habits can be shaped and changed, once this stage is missed, it is difficult to change.
Kissinger, because of his older age, had missed the opportunity to change his accent by the time he arrived in the United States. His younger brother, who was only a year younger than him, had just caught the last train of language learning, so he could learn an authentic American accent. This phenomenon is called the "imprinting effect", and the imprinting effect is the perfect embodiment of the interaction between successive days.