The evolution of morality

Anastasia Kazantseva, STRF.ru

Darwin wrote that higher mental functions underwent gradual changes under the influence of selection, as well as the structure of the body. He believed that in the future psychology would be based on understanding the evolutionary origin of various traits of the psyche. Now, 150 years after the publication of The Origin of Species..., we are finally approaching this situation. The synthesis of neurophysiology, psychogenetics, ethology and other sciences led to the formation of evolutionary psychology – a field of knowledge that explains how and why humanity acquired the ability to love, or to altruism, or to religious experiences: what kind of pressure of natural selection, what specific changes in the genetically programmed structure of the brain led to the fact that such higher mental the functions turned out to be useful for our ancestors. Biologist Alexander Markov told about some recent achievements of evolutionary psychology.

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Markov Alexander Vladimirovich, biologist, specialist in the theory of evolution, leading researcher at the Laboratory of Higher Invertebrates of the Paleontological Institute of the Russian Academy of Sciences. Markov gained wide fame thanks to his popularizing work: he created the website "Problems of Evolution", wrote the book "The Birth of Complexity" (finalist of this year's Enlightener Award) and regularly gives public lectures. One of them, "The Origin of Reason, Emotions and Morality", was held on Thursday, November 25, at the Darwin Museum as part of public readings dedicated to the centenary of the magazine "Nature".

Photo: Ignat Solovey

Humanity obtains knowledge about its own origin with the help of three sciences. The first two, paleoanthropology and genetics, are well known to everyone: the first one told us about how our ancestors looked and what they did in the last six million years, and the second one searches and finds differences between our genome and the chimpanzee genome and identifies single significant changes among this miserable 1 percent of nucleotide pairs. The third science was formed recently (although it was predicted by Darwin 150 years ago) and is called evolutionary psychology. Markov's lecture is an overview of some recent achievements of this science.

At the beginning of the lecture, the scientist notes that specialists applying an evolutionary approach to the study of human behavior are constantly being attacked by poorly educated public, political and religious figures and quotes an article from the journal Nature – a response to the anti-evolutionary statements of American politicians: "Both the human body and mind evolved from earlier primates. The way of human thinking testifies to such an origin as convincingly as the structure and work of the limbs, the immune system or the cones of the eye. This applies not only to the mechanism of neurons, but also to various aspects of our morality."

Scientists' confidence in the evolutionary origin of the "soul" is based on a huge body of data from neurophysiology, behavior genetics, ethology and other disciplines. There are four main areas of research that confirm that human behavior can be considered as a result of evolution. Firstly, there is a neurophysiological basis of behavior: specific areas of the brain are associated with any mental function. Secondly, another new science – psychogenetics – has already accumulated a large array of data demonstrating the relationship between the genotype and the behavior of an individual. If we add to it psychoendocrinology, the science of the relationship between hormones and behavior, then very little will remain of "ourselves". Thirdly, the line between man and animals, which was talked about so much in the XX century, is blurring more and more every year. And finally, evolutionary psychology has the most important feature of science: on the basis of the accumulated data it can build theories and test them experimentally.

The ability to exhibit any behavior is provided by our brain. With malfunctions in the brain, behavior is often disrupted. Markov talks about people with damage to a certain part of the brain – the ventromedial prefrontal cortex. Their intellect is completely preserved, but the ability to empathize and feel guilty disappears. "Such people make a moral judgment based on cold calculation, that is, they simply calculate which of the options in total will give more good, less bad. And healthy people always take into account their emotions at the same time," Markov explains and shows a picture of trains.

In this standard psychological test, two situations are given: in the first, you can switch the railway arrow to save five children, but sacrifice one who is also playing on the rails, and in the second situation, the only way to save the children is to push a person off the bridge. "A normal person sees, feels, or rather, a very big difference between these two situations," explains the lecturer. A person with brain damage does not see such a difference.

But how did it happen that the ability to empathize turned out to be an evolutionary advantage?

The Evolution of AltruismToday, enough data has been accumulated to say with confidence that the propensity for good deeds is determined not only by upbringing, but also by genes.

Of course, it is not so easy to separate one from the other (kind parents will bring up kindness in children), but it is still possible. Firstly, there is a twin analysis: comparing the behavior of genetically identical monozygotic twins with the behavior of dizygotic twins, who are no more close to each other than any siblings, allows us to identify signs that are controlled by genes. Secondly, when the search area is clear, it is possible to identify statistical links between the behavior and genotype of large groups of people. Such studies show that variations of the OXTR and AVPR1a genes encoding the oxytocin and vasopressin receptors are significantly associated with the tendency of people to do good deeds to the detriment of personal gain.

There are several complementary theories of the development of altruism. Firstly, kinship selection included in textbooks and mathematically verified: it is beneficial to help a close relative, because he spreads the same genes as yourself. "I would give my life for two brothers or eight cousins," Markov quotes evolutionary biologist John Haldane. Kin selection can be maintained even in primitive animals, but the second kind – reciprocal, or mutual, altruism already requires a developed nervous system, the ability to remember a partner and predict the future, so this form of altruism is studied mainly by the example of monkeys.

But for people with their complex social organization, parochial altruism comes to the fore, that is, altruism focused on "their own" and combined with a willingness to show aggression to "strangers". In all likelihood, the group whose members are prone to such behavior in prehistoric times survived and left offspring most effectively. Archaeological data show that the level of intergroup aggression among Paleolithic tribes was very high: up to 30 percent of people died violently! And if we assume that the existence of altruistic heroes in the tribe increased his chances of winning the war, then their genes should have been fixed by natural selection, despite the likelihood of the death of their carriers. At least one gene involved in the support of parochial altruism can be identified with a high degree of confidence – this is the same receptor for oxytocin, variations of which affect the propensity for good deeds. This hormone is usually mentioned in connection with love and trust. In addition, there is a lot of experimental data confirming its role in these processes. But the function of this hormone turned out to be ambiguous: not so long ago, there were studies demonstrating that oxytocin does not enhance – and in some situations even reduces – sympathy for members of the "alien" group and the trust and love caused by it extend to "their own".

Loyalty to a womanAbsolutely any popular scientific biological article can be called "about mice and humans".

This time, the famous Larry Young voles (mountain and steppe) act as mice. These two close species build a family in different ways: steppe voles form stable pairs and take care of their young together, while mountain voles are promiscuous, and their males are completely indifferent to offspring.

This difference between the species is due to small differences in the structure and distribution of receptors for oxytocin, vasopressin and dopamine in the brain. For example, a male monogamous vole can be injected with vasopressin, and he will love the first female he meets forever. With a male polygamous vole, such a number will not work: only genetic engineering can make him monogamous.

One of the important differences between polygamous and monogamous voles is the length of the regulatory region in the gene encoding the vasopressin receptor (V1a). In polygamous voles, this area is shortened compared to monogamous ones. In humans, there are different variants of the vasopressin receptor.

It was found that in men with a shortened regulatory region of the V1a gene, romantic relationships are half as likely to lead to marriage. In addition, they are twice as likely to consider themselves unhappy in family life. Wives of people with this variant of the gene are usually dissatisfied with family relationships.

There is nothing surprising in the fact that genes can influence a person's love experiences. The development of emotional areas of the brain, the level of hormones and neurotransmitters, the sensitivity of the corresponding neural networks to them depend on genes – and hence the difference in the intensity and even the sign of emotional reactions to similar stimuli of the external environment. Today, a lot of work is being carried out related to the study of human attachments from the point of view of neurophysiology: the brain areas involved in the experience of love are known, many hormones that affect the feeling of attachment are known, many discoveries are related to smell communication in humans. But all these factors have statistical significance. Biologists know a lot about love in general, and not about the love of a particular couple. For now.

Religion and other adverse reactionsSometimes the evolution of the brain leads to the formation of very strange behavior, at first glance inexplicable.

For example, in most human communities, systems of religious beliefs were formed, and many of them have survived to the present day. The fact that religions are created and supported suggests that they bring some benefit to the collective.

Another new science, evolutionary religious studies, offers two main approaches to explaining the existence of religion. It can be considered as a side effect of the evolution of some other mental functions or as a useful adaptation. "These two approaches are not mutually exclusive," Markov notes, "because it often happens that the by–product of some evolutionary change simultaneously turns out (or subsequently becomes) also a useful adaptation."

Human cubs show a great ability to indoctrinate, that is, to unconditionally believe in any theses proposed by adults. This is very profitable, says Markov: "It is clear that, other things being equal, it is much safer, more convenient, and faster to learn from adults than from your own mistakes." Children who tend to take adults at their word survive better and pass on their genes, because they will not eat beautiful poisonous berries if their parents forbade them to do so. But as a result of this adaptation, "an ideal environment arises for the appearance and spread of all kinds of selfish fragments of information, various kinds of information viruses," the lecturer notes.

Another important prerequisite for the formation of religion is the formation of large communities in which not all people know each other by sight. "This is a very resource–intensive behavior in intellectual terms," explains Markov. Monkeys have a correlation between the size of the brain and the size of a social group, but humans could not increase the size of the brain indefinitely. We had to look for other ways to support large groups: "And one of these adaptations, apparently, was the ability to recognize and appreciate complex, expensive and difficult-to-make signals, the meaning of which is "I am one of my own, I am one of the group, I am one of you, I can be trusted." And religions could use this property of the psyche for their dissemination. It is no coincidence that many religions attach great importance to the most expensive, exhausting rituals."

There is a lot of evidence demonstrating that religions contribute to the preservation of the group. In the XIX century, many different communities emerged in the USA – both religious and secular. Religious communities have lasted longer on average, which illustrates the value of religion as a tool for maintaining collective cohesion. Moreover, it turned out that the survival of religious communities directly depends on the strictness of their charter. Grueling rituals, fasts and similar things are an effective way to identify individuals who do not show proper loyalty to the community.

In addition, collective rituals serve as an important means of strengthening parochial altruism, that is, love for one's own and hatred of strangers. Studies conducted among representatives of six religious denominations have demonstrated a clear relationship between the frequency of attendance of divine services and the number of positive answers to two questions: a) are you ready to die for your faith? b) do you think that the Gentiles are to blame for many of the troubles of this world? It is important that the researchers did not find a correlation with the frequency of prayers – we are talking about collective rituals, not individual beliefs.

The brain is material. What to do?Most of the studies mentioned by Markov in his lecture date back to 2010.

This happened because the number of papers devoted to various aspects of evolutionary psychology is increasing today in an avalanche, the data are continuously being refined, rechecked on larger samples, new genes and their new effects on the psyche are being discovered. Today we still don't know much about how our brain works, but in a few decades, apparently, the understanding of the biological foundations of behavior will reach a level comparable to the understanding of the circulatory or digestive system achieved today.

Understanding the biological foundations of behavior greatly simplifies life. It's not you who are throwing plates against the wall, it's the lack of progesterone that makes decisions for you. And that's why we often hear that such studies do not need to be popularized at all – supposedly they can justify ugly behavior. Markov does not agree with this interpretation: "The evolutionary approach to man – he explains where everything came from, but in no way answers the question of what is good and what is bad. The question of what is good and what is bad is answered by human culture. This is the result not of biological, but of cultural and social evolution, which has long been much more important to us than biological evolution."

To illustrate this idea, the lecturer gives an example: "You know, geneticists have found such a DNA fragment in a person, the presence of which increases the likelihood that a person will become a murderer several times. Either 5, or 10 times. This is a real statistic." The audience tries on themselves, worries.

"Do you think," Markov continues, "we should give people, the carriers of this DNA fragment, some indulgences in court, somehow treat them more leniently?". The audience, convinced during the lecture of the importance of biological factors, believes that rather yes. In fact, if it takes 10 times more effort from one person to suppress aggression than from another, does this not mean that it is necessary to develop ways to identify this DNA site and take preventive measures to suppress its work in the body?

Actually, it would be nice, probably. But not everything is so simple. The lecturer pauses: "Have you guessed which DNA fragment we are talking about, what is it called? And I'll tell you. The Y chromosome."

Portal "Eternal youth" http://vechnayamolodost.ru30.11.2010