Dunbar's research found that the number of social relationships that human beings can have is around 150. Why?
On the one hand, it is empirical. For example, according to the survey data of more than 20 tribal societies, the average size of these clan groups is 153. Around 6000 BC, the number of Neolithic villages in the Middle East seems to be between 120 and 150. 1 1 the traditional scale of English villages in the century is also about 150 people; /kloc-the average number of English villages in the 0/8th century is also160; In modern society, companies with less than 150 employees can operate efficiently on the basis of good interpersonal relationships. In the modern army, the smallest independent unit is the company, and the general total number is about 130- 150. Even during the Roman Republic, the basic combat unit (infantry squadron or unit) of the Roman army was similar in size, about 130.
On the other hand, due to the information constraint of social relationship quality, the human brain can only support us to have 150 friends. Among them, 3-5 people closest to us contact at least once a week; 15 people who are slightly alienated contact about once a month; /kloc-a large circle of 0/50 people, contact once a year or so.
From this point of view, to a certain degree of intimacy, the people we can get along with seem to be limited. There are only so many seats in the nearest social circle. If someone you don't know suddenly becomes the most important person in your life, then someone is bound to be squeezed into the next slightly larger concentric circle to make way for her/him. When a boy falls in love with a girl, one of the boy's five closest friends must give way. This is the so-called "putting color before friends".
The weight of the human brain only accounts for about 2% of the total body weight, but the energy consumed is equivalent to 20% of the total energy intake of the human body. It seems that the human brain is a super luxury. But we know that evolution is extremely energy-saving, and the brain must be worth such a big price.
Studies have found that pairing and combination seem to be the real source of brain consumption. Among most birds and mammals, the species with the largest proportion of brain in the body is monogamous-monogamy has a long history. Those indistinguishable social birds or herds that mate indiscriminately have much smaller brains.
One possible reason is that long-term monogamy will take unusual risks. If the spouse is not chosen properly-once he chooses an infertile, lazy or unfaithful spouse-it will directly threaten his contribution to the species gene pool. It can be seen that it is extremely important to have a big enough brain at all costs so that animals can identify who is worthy of being entrusted for life at a glance; The other is that the long-term life of husband and wife needs a lot of flexible and complicated skills in order to effectively foresee and deal with all potential disputes and differences in the second half of life and better raise future generations.
So, if you are still at a loss for three or two days because of your spouse's bad behavior, and shout that a woman's heart is like a needle, you might as well comfort yourself by saying: Thanks to the gift of evolution, you have one of the most brilliant glories in nature-the brain, which enables you to be good at adversity and face difficulties, and then it will be smooth sailing.
Women always seem to have a mysterious perception of whether your statement about where you have been all night is true or not.
That's about it. About13 women can see four basic colors, while men can only see the standard three basic colors (red, blue and green), and some women can even see all five colors.
Why? Because the genes for color processing are located on the X chromosome, men have only one X chromosome (inherited from their mothers) and women have two X chromosomes (one from their parents). When there is a slight mutation in the gene encoding color-sensitive pigment in the retina, the chromaticity that men get from the only X chromosome is the chromaticity they can see, while women can see red or green with slightly different chromaticity because they have two X chromosomes. If these two chromosomes are active during the development of eyes, then these women's cone cells can encode two kinds of color sensitivity, so there is another color dimension, and in some cases, there are even two-blue, red, red, green and green, and they can see five basic colors in total.
In other words, women have the ability to distinguish subtle color changes on their spouses' faces, while men think it is not easy to detect them at all. When some questions make men's faces change greatly, they are caught at once.
Steven Pinker, a famous linguist, once said that music is "the luxury temptation to enter chemistry".
However, what makes a species willing to invest so much time and money in evolution will never be just a trivial by-product of evolution. Once animals spend a lot of time and energy on something, it is usually because it is very important in the basic biological sense.
Darwin himself originally put forward a view that music is a kind of "sex advertisement", which mainly comes from the singing function of some birds. Being able to create complex melodies with your own playing and singing skills clearly shows the qualities in your genes that can attract potential spouses. Geoffrey Miller, an evolutionary psychologist, found that jazz musicians, pop musicians and classical composers were always the most productive in their lives.
One of the author's students, costas Casca Tis, specializes in the creation of19th century European classical composers (from Beethoven to Mahler) and 1960s retro rock stars. He found that after these composers and singers get married, the number of new works often drops sharply, but once they are separated or divorced from their wives and look for new spouses, the number of new works will pick up again. Once they find a new spouse ... yes, the number of works will drop again.
It seems that marriage will drain people's talents. Don't get married if you want to be famous.
Of course, there is also a saying that music can be a trigger for the human body to release endorphins, which can bring happiness and satisfaction and are crucial to the establishment of social ties. Therefore, we can see that people always use singing and dancing to create a sense of belonging or community, which is essential for building cohesion in small-scale human society. When the author wrote this book, the magical activities that filled the land of China had not yet appeared. Now asking him to experience the square dance in full swing at dusk in a community will definitely strengthen this view.
Of course, Darwin is not necessarily wrong. Sexual selection may use some skills and emotions needed for music creation with ulterior motives, which originally evolved for completely different purposes. But fundamentally speaking, the real origin and function of music should probably be to establish links between social groups. This may also be the origin of language. Knowing the real function of music, should such a constructive thing be carried out at high frequency?
With a little attention, it is not difficult to find that the preferred conversation topics of men and women are often quite different. Men like to talk about themselves, while women like to talk about others.
The main purpose of men's conversation seems to be to sell themselves. They either talk about themselves or talk about things they think they know very well. This is a kind of peacock tail with sound (peacock tail is Darwin's heart disease for many years, because it is a burden from the perspective of survival, but why has evolution survived? Later, his old man realized that the seemingly cumbersome tail is actually a strong signal that I still live well under such a burden, and the brighter the tail, the better the individual's health.
It is said that male peacocks will wander around their mating area, and as long as they see the female peacocks in sight, they will scramble to show their beautiful and colorful tails. The female peacock wandered among the male peacocks to see which tail was the most dazzling, so she chose it as her spouse. Humans seem to realize this process entirely through language. Just as a male peacock suddenly opens its screen when a female peacock appears, when a man sees a woman present, he will immediately switch the conversation to propaganda mode.
You can listen carefully to a man's conversation when only other men are present, and then compare it with the conversation of the same man when there is a woman next to you. With a woman present, his conversation style will change greatly. At this time, he will be more eager to show off, and will also add some funny content to the conversation, causing laughter from people around him. However, in addition, you will also hear conversations about professional topics that show that men's "knowledge" has become more radical. It is a man's declaration to make the conversation competitive.
Women's conversation mainly serves their social network, and they want to build and maintain a complex social network, which is constantly developing and changing. It is very important to always pay attention to what others are doing, which also implies that you are a member of a small circle and people are willing to talk to you about this topic. This is not a boring speech, but the core of the social turntable and the foundation for the establishment and operation of society itself.
Essentially, the difference in conversation is only because men and women play different roles in social life.
The length of pregnancy in all mammals is determined by the size of the brain. The growth rate of brain tissue seems to be predetermined, so if you want to have a bigger brain, you can only make the pregnancy longer, so that the brain will grow. Therefore, species with larger brains have longer pregnancy periods.
The problem with humans is that our brains are bigger. According to the relationship between the brain size of other mammals and the length of pregnancy, human pregnancy should be 2 1 month. But as we all know, a person is only nine months pregnant.
The reason is simple: millions of years ago, our ancestors thought that growing a bigger brain was very useful, and they thought that walking upright was more useful. This has enabled humans to evolve a very unique bowl-shaped pelvis, which is very different from the slender pelvis of other monkeys and apes. With a bowl-shaped pelvis, we can better keep the balance between the body and the head, especially after we have a bigger protruding brain. Although the evolution of modern human pelvis has a history of nearly 2 million years, it is still impossible to have a perfect engineering design in the evolution.
In order to stride a long distance, one of the sacrifices that human beings must bear is that our waist becomes weak. The bowl-shaped pelvis narrows the birth canal a lot, and as a result, … the women burst into tears during childbirth.
At this point, our choices are extremely limited. Of course, we can go back and give up the stupid idea of having a bigger brain. This means that we are stagnant in evolution and stagnant. Because of climate change, the world at that time has undergone earth-shaking changes, and the consequence of stagnation is extinction. In order to survive, we must change and go out to adapt to the new environment. In the new environment, a bigger brain is very important. Therefore, the lesser of the two evils, evolution finally chose to let women suffer and let the baby premature.
After appreciating the compromise of evolution, let's take a look at the wonders of evolution. When you are a new father, it is very important for a man to pay special attention to what his children look like. Like, right? Don't look, you can bring any man, like.
Generally speaking, human babies look alike, and even in fact, all human babies have blue eyes at first, and then they become brown or green eyes. Why? Because women have to cooperate with men to raise children, in order to make men willing to cooperate, you must convince men that this is his child.
At this time, the baby faces two choices on the road of evolution: one is to look like his father and look exactly the same; Second, he looks nothing like his father. As long as the father is really the father of the child, the first choice is not troublesome, but we know that people are very complicated and there are likely to be so many babies who are not their own (about 15% mentioned above), so the second choice may be more sensible. Whose child is this? Let dads guess. Everything is based on imagination. As long as you look carefully, you can always find some places like Lao Wang next door.
Next, if your parents-in-law and wife keep saying that the baby doesn't look like you, you will be very moved.
4/5 pregnant women will have vomiting or anorexia in the first 3 months of pregnancy. At first, doctors thought that morning sickness was just an unwelcome side effect of hormone changes during pregnancy, and we should certainly try our best to eliminate it. Therefore, phthalamide piperidone was developed to relieve symptoms. As a result, in just a few years in the 1960s, tens of thousands of extremely rare cases of limb deformity of seals occurred in the world.
In fact, pregnant women's morning sickness seems to be beneficial to the human body-or at least to the baby. Women who have nausea symptoms in the first three months of pregnancy will greatly reduce the probability of losing their children due to spontaneous abortion, and the children born may be bigger and more beautiful.
In fact, many foods we eat every day are slightly toxic, sometimes even simply toxic, and we often can't resist the temptation of delicious food or are obsessed with the stimulation they bring-such as alcohol, coffee and pepper. If you eat too much, many of these foods may cause cancer, and many of them are teratogens.
Adults have a certain tolerance to these toxins, because the small doses we ingest are scattered in our larger bodies, and the toxins can be diluted. However, the fetal body is very small, and even if only a small dose of one of the toxins is ingested through the mother, it may have extremely harmful consequences. In fact, pregnant women's morning sickness is that children try to prevent their mothers from eating too much food that is not conducive to the fetus.
It can be seen that the body is slightly unwell and should not take medicine at all. Taking medicine is to inhibit the normal reaction of the body, but it harms the body. For example, a cold is a periodic disease. Generally, it will heal itself in about 7 days without taking medicine, but taking medicine prolongs the course of disease. However, please analyze the specific problems. This article does not constitute a personal health point of view. Please follow the doctor's advice.
Arnold Schumacher of the University of Hamburg in Germany found that successful people often look taller than they really are. He found that in all industries, from business managers, nurses to carpenters and other handicrafts, in the career ladder, people with higher status are indeed much higher than those with lower status, even if the age difference is taken into account.
For example, in the sample of German enterprise managers, regardless of gender, class background and educational background, the average height of senior managers is 5 cm higher than that of people in lower positions. Another fact is that since George Washington took the presidency of the United States, it has been found that in 765,438+0% of the American presidential elections, the last two electors were tall and won the general election.
Elizabeth Hill of tulane university and Elaine Knox of Furman University found that whether a person can attract others' attention depends largely on what clothes they wear. In the experiment, they let a person put on designer clothes and expensive jewelry first, and then let him or her put on ordinary clothes. The former shows higher social status and greater charm than the latter.
Why does height and appearance play such an important role? The truth should be this: we are always trying to find clues that can identify successful people. After all, if we can afford beautiful new clothes, this person can't be so bad. Height and appearance (facial symmetry) show that a person can grow into a tall and symmetrical figure even if he encounters various impermanent changes in his life-from illness to trauma to hunger and a long period of growth and development. Isn't this the embodiment of his excellent genes?
Freud and his companions insisted that kissing only reflects people's desire to go back to childhood, and it evokes beautiful memories of breastfeeding deeply rooted in our hearts. Another way of saying it is that kissing is a form of courtship feeding and a common habit of insects and some birds.
In fact, kissing is probably a way to test the genetic composition of future spouses. Everyone has a unique immune system, and kissing mainly depends on a small cluster of genes, the so-called "major histocompatibility complex", or MHC for short. MHC gene determines the range that individuals can recognize and resist when foreign objects (from pollen to virus to bacteria) invade. This group of genes is particularly prone to mutation. Only in this way can we adapt to the threats brought by the ever-changing tiny world, in which parasites always invade our bodies and threaten the survival of individuals. MHC gene also determines our body odor, because it turns out that people's natural body odor is closely related to their immune system.
A series of long-term studies show that people prefer to combine with people with complementary MHC genes. There is a simple reason. If your spouse has the same immune response as you, your child's immunity will be limited. But if your spouse's immune system is complementary to yours, your child will be immune to more diseases. This truth is somewhat similar to not marrying a close relative.
So, how do you know that your future spouse's immune response is only complementary to yours? Smell is a way of identification, and it is easy to be covered up by a lot of dust and bacteria. Therefore, the best way is to get closer and "lick" each other's body odor directly.
So, when you kiss someone for the first time in the future, you will know that God damn it wants to test your genes.
It is found that men are more likely than anyone to save (or try to save) young women who have nothing to do with themselves, while women are more likely to save their children. In other words, for women, heroic behavior is bound to be related to investment in their children, while for men, those behaviors seem to be more about getting a chance to choose a spouse.
The author and his students found that in a large number of reports in British newspapers about people trying to help others in an emergency, almost all rescuers are men, and rescuers generally come from lower socio-economic classes, and men from richer social classes rarely pretend to be heroes. Indian Cheyenne tribes in the history of North America have a very similar trend. /kloc-demographic records at the end of 0/9 century show that almost all war chiefs are orphans or sons of low-ranking members of the tribe. Because of their low social status, these people have little chance to find wives. But successful war chiefs-those who can leave the battlefield with honor and rejoin the normal society after a long battle-are very popular. Generally speaking, although they have a spouse for a much shorter time, they have more children than peace chiefs.
Adventurers are more successful in breeding offspring, and those who are more willing to take risks have obviously more children than those who are unwilling to take risks. Although this phenomenon has not been clearly explained (people who are more willing to take risks are more likely to have unprotected sex, or they are just more attractive to women). In short, men who are willing to take risks contribute more to the next generation of gene banks.
In today's world that places too much emphasis on vision, we often forget the importance of smell. In fact, we use our sense of smell more often than we think-especially when choosing a spouse.
As early as 1960s, some pranksters sprayed androsterone (a member of steroid family, a natural by-product of testosterone, so-called androgen) in the compartments of men's and women's toilets. If men shave without aftershave, they often have a slight musty smell, and then observe people's reaction.
As a result, they found that men don't go to those compartments sprayed with androsterone-even if they accidentally go in, they usually quit quickly and find a compartment that doesn't smell like this. The women went into the bathroom and went straight to the compartment sprayed with androsterone.
Later, when women needed speed dating, they did some tests. Among them,13 women smelled androstenedione and clove oil (the smell of androstenedione was covered with clove oil to control the effect of other smells),13 women only smelled clove oil, and the remaining13 women only sprayed colorless. The experimental results are amazing. Women who sprayed androstenedione not only rated the charm of men they met when they needed speed dating higher than the other two groups of women, but also invited each other to meet again with a much higher probability.
In a sense, androstenedione plays a role in some mechanism buried deep in our brain, which makes us have a more romantic rather than realistic idea about the ugly man standing in front of us.
Remember to bring the element detector before meeting for the first time.
Scientists have found that the vasopressin receptor gene has a strong correlation with the stability of male marriage. One of the special gene loci, RS3, varies from person to person, and can be used as a function of men's score in marital firmness to measure their marital loyalty. Among the 1 1 different gene variants of this locus, one (allele 334) showed the strongest effect.
Men who have one or two copies of 334 allele (in other words, one from one parent or one from both parents) have lower scores on marital stability than men who have other 10 allele combinations. They are also more inclined to live with their spouses than to get married, which shows that they are not so loyal to marriage.
Among men with two copies of 334 gene,13 reported that they had suffered a marital crisis in the past year, while in men with only one copy of 334 gene, the proportion was 16%, and in men without 334 allele at all, the figure was 15%. Although in fact, all the men in the sample have a stable relationship with their spouses for at least 5 years and have at least 1 children with their spouses.
In this Swedish sample, about 4% of men have two alleles of 334, and 36% of men have only one allele. In this way, almost two-thirds of men do not have copies of this gene, so they are likely to be good partners who faithfully implement monogamy. A large sample survey in Quebec also found a similar proportion: about13 men often promiscuous, while 2/3 men are monogamous (at least in their stable marriage).
Maybe it is necessary to have a genetic test before marriage. For example, give him a cigarette, and then take it down and send it to the genetic laboratory. Now, researchers can extract his DNA samples from saliva spots and scan them to determine whether there is allele 334 at the RS3 gene locus. If the test results are positive, it is not a good idea to marry him; And if the test results are double positive, it would be terrible to marry him.
Over the past year, several friends have kindly reminded me not to always talk about men and women. Here, let me clarify.
First of all, real human events are two things, survival and reproduction. Of course, the root of survival and reproduction is the role of genes. Man is just a carrier. Interested people can read The Selfish Gene (which is in my reading notes). Survival is actually an impossible road, because it is difficult to achieve eternal life. Besides, immortality is not the best evolutionary strategy, but reproduction is. Only by reproduction can there be variation, and only by variation can there be new abilities. If our ape ancestors lived millions of years ago forever, there would be no us. Race without mutation will be particularly vulnerable. Once the environment changes, it may become extinct, because the same is reproduction and its subsequent variation, resulting in colorful species and flowers, which can continue the race under repeated natural disasters.
Secondly, in addition to the environment is the driving force of evolution, there is also a driving force, that is, sexual selection. Since reproduction can continue species, how each individual in each species can reproduce himself and more offspring is the core problem. In order to reproduce, every creature and individual in the biological race is really eight immortals crossing the ocean, showing their magical powers. Let's take a look at our own kind. According to the calculation of Robin Baker and Mark Behles, two scientists from the University of Manchester, England, among the babies born in England, 10%- 13% was not born by a legal spouse. People who are interested can go to see Love and Sex of Marine Life, which is really an eye-opener. For example, the sex organs of female cetaceans are not tubular, but have a series of petals, folds, blind ends and funnel-shaped structures, which are particularly like mazes for sperm. Scientists believe that this is because they are accustomed to promiscuity with the opposite sex and often accept sperm from different men. In order to screen out the sperm she wants most, the mother whale may use her complex organ structure to filter out most of the sperm and guide the remaining sperm to the destination. For example, dolphins have a particularly strong sexual desire, and they have to have sex many times a day, which requires a particularly high demand for male genitalia. In fact, the male genitalia of dolphins are supported by thick tissue fibers, which have certain elasticity while maintaining hardness. This structure can not only help them get an erection quickly, but also protect them from injury.
Third, discussion is not equal to practice. If you read Freud when you are young like me, you will easily fall into the universal theory if you are not careful. Fortunately, I have come out and can't analyze everything from a sexual perspective, including biology. Evolution is the background of human behavior, but not the whole. Freud explained everything from a sexual point of view. I don't think there is anything to gossip about his personal experience. In his later years, his old husband was more like a gangster. Of course, in the eyes of his followers, he created a religion. Me too. I'm just saying. Just study and discuss, no practice. However, just because you don't practice doesn't mean that what you are discussing is wrong. There are many channels to understand human nature, such as reading long and serious novels and showing me English dramas and American dramas. At the same time, the subject of my study this year is "biology", and the issue of reproduction-sexual selection is something that can't be avoided anywhere in the theory of evolution, and I can't help it.