In this article, I propose to make an excursion into sociobiology and talk about the evolutionary origins of altruism, kin selection and aggression. We will briefly (but with references) review the results of sociological and neuroimaging studies, which show how recognition of relatives in people can influence sexual behavior and promote cooperation, and on the other hand, recognition of a member of a foreign social group can increase the manifestation of fear and aggression reactions. Then we recall historical examples of the manipulation of these mechanisms and touch on the topic of dehumanization. And finally, let's talk about why research in this area is critically important for the future of humanity.
Contents:
1. Amoebas-heroes and bees-volunteers are examples of altruism in nature.
2. Self-sacrifice by calculation kin selection theory and Hamilton's rule.
3. Brotherly love and disgust - Taiwanese marriages and Jewish kibbutzim.
4. Tonsil of discord - neuroimaging of racial prejudice.
5. Fake Relationship - Real Collaboration - Tibetan monks and guest workers.
6. Inhumans. Dehumanization propaganda, empathy and aggression.
7. What's next? - in conclusion, why all this is very important.
The word "brother» in Russian is used not only to refer to biological relatives, but also to refer to members of a group with close social ties. So the single-root word "brotherGUSTs" denotes a community of people with common interests, views and beliefs [1] [2], the English equivalent of the Russian brotherhood - "brotherhood" also has a common root with the word "brother"- brother [3] similarly in French, brotherhood -"withfrerie", Brother - "brother", and even in Indonesian, "foryouan"-"you". Can this universal pattern indicate that such a social phenomenon as “brotherhood” has direct biological roots? I propose to delve a little deeper into the topic and see how the evolutionary-biological approach can give a deeper understanding of social phenomena.
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Hero Amoebas and Volunteer Bees
Kinship relationships, as a rule, imply an increased level of altruism. Altruism, as self-sacrifice and willingness to give up one's own interests for the benefit of others, is certainly one of the most outstanding human qualities, or not only human?
As it turned out, animals are also quite capable of showing altruism, including many insects living in colonies [4]. Some monkeys give an alarm signal to their relatives at the sight of predators, while endangering themselves. In bee hives there are individuals that do not reproduce themselves, but only take care of other people's offspring all their lives [5] [6], and amoebae of the dictyostelium species (Dictyostelium discoideum), when unfavorable conditions for the colony occur, sacrifice themselves, forming a stalk on which their relatives rise above the surface and get the opportunity to be transported in the form of spores to a more favorable environment [7].
Examples of altruism in the animal world. Left: fruiting body in the slimy mold Dictyostelium discoideum (photo by Owen Gilbert). Center: Brood of the ant Myrmica scabrinodis (photo by David Nash). Right: Long-tailed tits care (photo by Andrew MacColl). Source:[6]
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[6] (06)01695-2
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Self-sacrifice by calculation
Okay, primates, but self-sacrifice in insects and unicellular organisms? Something is wrong here! would have exclaimed a Darwinist of the beginning of the last century. After all, risking for the sake of another, an individual reduces its chance to produce offspring, and, following the classical theory of selection, such behavior should not be selected.
All this made adherents of Darwinian natural selection seriously nervous, until, in 1932, John Haldane, a rising superstar in evolutionary biology, noticed that altruism can be fixed if it is directed at relatives, and formulated this principle, which later became a catch phrase [8]:
"I would give my life for two siblings or eight cousins."
Hinting that siblings are genetically 50% identical, and cousins only 12,5%. Thus, thanks to the work of Haldane, the foundation of a new “synthetic theory of evolution” began to be laid, the main character of which is no longer an individual, but genes and populations.
Indeed, if the ultimate goal of an organism is to spread its genes, then it makes sense to increase the chances of reproduction of those individuals that have more genes in common with you. Based on these data and inspired by statistics, William Hamilton, in 1964, formulated a rule later called Hamilton's rule [9], which states that altruistic behavior between individuals is possible only if the ratio of their common genes, multiplied by the increase in the probability of transferring a gene for an individual to which altruism is directed, will be greater than the increase in the risk of not transferring their genes to an individual that performs an act of altruism, which in its simplest form can be written as:
Where:
r (relatedness) - the proportion of common genes between individuals, for example. for siblings ½,
B (benefit) - an increase in the probability of reproduction of the second individual in the case of altruism of the first,
C (cost) - decrease in the probability of reproduction of an individual performing an altruistic action.
And this model has repeatedly been confirmed in observations [10][11]. For example, in a study conducted by biologists from Canada[12], for 19 years they tracked a population of red squirrels (a total of about 54,785 individuals in 2,230 litters), and recorded all cases when squirrels feeding their offspring adopted squirrels whose mothers died.
A female red squirrel is preparing to move a newborn between nests. Source [12]
For each case, the degree of relationship and the risk for the squirrels' own offspring were calculated, then by compiling a table with these data, the scientists found out that Hamilton's rule is observed to within the third decimal place.
Rows A1 to A5 correspond to cases when female squirrels adopted other people's children, rows NA1 and NA2 correspond to cases when adoption did not occur, the column "Inclusive fitness of adopting one juvenile" shows the calculation using the Hamilton formula for each of the cases. Source [12]
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[9]http://www.uvm.edu/pdodds/files/papers/others/1964/hamilton1964a.pdf
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As you can see, the recognition of relatives is an important selection factor and this is confirmed by a wide variety of mechanisms for such recognition, because it is important to understand with whom you have more genes in common, not only in order to determine in relation to whom it is more profitable to show altruism, but also in order to avoid sexual contact with closely related individuals (inbreeding), because the offspring obtained as a result of such connections is weaker. For example, it has been confirmed that animals can recognize relatives by smell [13], with the help of the major histocompatibility complex [14], birds by singing [15], and primates can even recognize those relatives they have never met with the help of facial features [16].
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Brotherly love and disgust
People are still more interesting and more complicated. A research team from the School of Psychology at the University of Aberdeen published in 2010 the curious results of a study[17] of how 156 women aged 17 to 35 rated photographs of the faces of various men. At the same time, to ordinary photos of random people, scientists secretly mixed images of faces artificially created from photos of the subjects themselves, in such a way as if it were a sibling, that is, with a 50% difference.
Examples of constructing self-similar faces from the study. A 50% difference of an artificial face was used, as if it were a brother or sister of the subject Source [17].
The results of the study showed that women more often rated self-similar faces as trustworthy, and at the same time as less sexually attractive. At the same time, the similar faces of those women who had real brothers or sisters were the least attracted. This suggests that the perception of kinship in humans, as well as in animals, can on the one hand stimulate cooperation and at the same time help to avoid inbreeding.
There is also evidence that non-relatives may begin to perceive each other as relatives under certain conditions. At the beginning of the 19th century, the Finnish sociologist Westermark, studying the sexual behavior of people, suggested that the mechanism for determining a relative could work on the principle of imprinting. That is, people will perceive each other as relatives and feel disgust at the thought of joint sex, provided that in the early stages of life they were in close contact for a long time, for example, they were brought up together [18][19].
Let us give the most striking examples of observations that testify in favor of the imprinting hypothesis. So at the beginning of the 20th century, kibbutzim began to gain popularity in Israel - agricultural communes numbering several hundred people, and along with the rejection of private property and equality of consumption, children in such communities were also brought up almost from birth all together, which allowed adults to devote even more time to work. The statistics of more than 2700 marriages of people who grew up in such kibbutzim showed that there were practically no marriages between those who were brought up in the same group during the first 6 years of life[20].
A group of children in Kibbutz Gan Shmuel, circa 1935-40. Source
Similar patterns were observed in Taiwan, where until recently there was the practice of Sim-pua marriages (translated as “little bride”), when the bride was adopted at the age of 4 by the family of the newly born groom, after which the future spouses were brought up together. The statistics of such marriages showed that they were 20% more likely to commit adultery, three times more likely to have divorces, and such marriages accounted for a quarter fewer children born [21].
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[20] Incest. A biosocial view. By J. Shepher. New York: Academic Press. 1983.
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Tonsil of discord
It would be logical to assume the evolutionary usefulness of the mechanisms for determining not only "ours" but also "them". And just as the definition of kinship plays an important role in cooperation and altruism, so the definition of a stranger plays an important role in the manifestation of fear and aggression. And in order to better understand these mechanisms, we will have to plunge a little into the fascinating world of neuropsychological research.
Our brain has a small but very important paired structure - the amygdala (amygdala), which plays a key role in emotions, especially negative ones, remembering emotional experience and triggering aggressive behavior.
Location of the tonsils in the brain, highlighted in yellow, source
The activity of the amygdala is highest when making emotional decisions and acting in stressful situations. Activating the amygdala suppresses the activity of the prefrontal cortex [22] - our center of planning and self-control. At the same time, it has been shown that people whose prefrontal cortex is better able to suppress amygdala activity may be less prone to stress and post-traumatic disorder [23].
An experiment in 2017 with the participation of people who have committed violent crimes showed that in the process of playing a specially designed game, the provocations of an opponent in the game more often caused an aggressive response in people who committed violent crimes, and at the same time, the activity of their tonsils recorded using the fMRI device was noticeably higher than in the control group [24].
"Amygdala reactivity" - signal values extracted from the left and right amygdala of the subjects. Violent criminals (red dots) show higher amygdala reactivity to provocations (P = 0,02).[24]
A classic study found that amygdala activity increased when viewing photographs of faces of a different race and correlated with the results of the Implicit Association Test for racial bias [25]. Further study of this topic revealed that the effect of activation on faces of a different race was enhanced if the image was presented in a sub-threshold mode for perception for a time of about 30 milliseconds. That is, even when a person did not have time to realize what exactly he saw, his amygdala was already signaling danger [26].
The opposite effect was observed in cases where, in addition to the image of a person's face, information about his personal qualities was presented. The researchers placed subjects in an fMRI machine and observed the activity of brain regions during two types of tasks, the subjects were presented with a visual stimulus in the form of random Caucasian and African faces and they had to answer a question about this person, for example, whether he is friendly, lazy or forgiving. At the same time, along with the photo, additional information was also presented, in the first case, not related to the person’s personality, and in the second, any data about this person, for example, that he grows vegetables in the garden or forgets clothes in the laundry machine.
Examples of tasks that were solved by the participants of the study. For 3 s, participants made a personal yes or no judgment on the image of a person's face (white or black male) and the information segment below the image. In the case of "superficial" judgments, the information segments were not personifying. In the model of "personal" judgments, information was personalized and described the unique properties and qualities of the goal. Thus, the participants were either given the opportunity to either individualize the image of the face, or not. Source [27]
The results showed a greater activity of the amygdala, in responses when it was necessary to make a superficial judgment, that is, when information not related to the personality was presented. In personal judgments, the activity of the amygdala was lower and, at the same time, areas of the cerebral cortex responsible for modeling the personality of another person were activated [27].
Top (B) Mean values of amygdala activity blue bar - corresponds to superficial judgments, purple - individual. Below is a diagram of the activity of brain regions associated with personality modeling when performing similar tasks [27].
Fortunately, a biased reaction to skin color is not innate and depends on the social environment and environment in which personality was formed. And evidence in favor of this was provided by a study that tested amygdala activation in images of faces of a different race in 32 children aged 4 to 16 years. It turned out that children's tonsils are not activated on faces of another race, until about the time of puberty, while the activation of the amygdala on faces of another race was weaker if the child grew up in an environment with racial diversity [28].
Activity of the amygdala on individuals of a different race depending on age. Source: [28]
To summarize all of the above, it turns out that our brain, being formed under the influence of childhood experience and the environment, can learn to recognize “dangerous” signs in the appearance of people and subsequently subconsciously influence our perception and behavior. So formed in an environment in which black people are seen as dangerous outsiders, your amygdala will set off an alarm when you see a person with dark skin before you can logically assess the situation and make judgments about that person's personality, and in many cases, such as when you need to make a snap decision or in the absence of other data, this can be critical.
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[26]https://www.ncbi.nlm.nih.gov/pubmed/15563325/
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Fake Relationship - Real Collaboration
So, on the one hand, we (people) have mechanisms for determining relatives that can be taught to work not at all for relatives, on the other hand, there are mechanisms for determining dangerous signs of a person that can also be subject to adjustment in the right direction and, as a rule, more often work on representatives of external social groups. And the benefits here are obvious, communities with higher cooperation among their members have advantages over more fragmented ones, and an increased level of aggression towards external groups can help in the competition for resources.
Strengthening cooperation and altruism within the group is possible when its members perceive each other as more relatives than they really are. Apparently, even the simple introduction of the appeal to the members of the community "brothers and sisters" can create the effect of pseudo-kinship - numerous religious communities and sects can serve as an example of this.
Monks of one of the main Tibetan monasteries Rato Dratsang. Source:
Cases of the formation of pseudo-kinship ties are also described as a useful adaptation within the ethnic groups of emigrants working in Korean restaurants [29], so the work team, becoming a pseudo-family, receives benefits in the form of increased mutual assistance and cooperation.
And it is not surprising that this is exactly how Stalin addressed the citizens of the USSR in his speech on July 3, 1941, urging them to go to war against the German troops [30].
[29]https://journals.sagepub.com/doi/abs/10.1177/1466138109347000 [30]https://topwar.ru/143885-bratya-i-sestry-obraschenie-iosifa-stalina-k-sovetskomu-narodu-3-iyulya-1941-goda.html
Inhuman cruelty
Human communities are distinguished from animals and other primates by a greater predisposition to cooperation, acts of altruism and empathy [31], which can serve as a barrier to the manifestation of aggression. Removing such barriers can increase aggressive behavior, one of the ways to remove barriers can be dehumanization, because if the victim is not perceived as a person, then empathy will not arise.
Neuroimaging shows that when viewing photographs of representatives of the “extreme” social groups, such as the homeless or drug addicts, the zones responsible for social perception are not activated in the brain [32], and this can create a vicious circle for people who have fallen to the “social bottom”, because the more they sink, the less people will be ready to help them.
A Stanford research team published a paper in 2017 showing that depersonalizing the victim increased aggression in cases where a benefit, such as a monetary reward, depended on it. But on the other hand, when aggression was committed according to moral criteria, for example, as a punishment for committing a crime, a description of the victim's personal characteristics could even increase the approval of aggression [33].
The average willingness of the subjects to harm a person, depending on the motive, on the left, the moral motive on the right is to receive a benefit. The black columns correspond to the dehumanized description of the victim, the gray columns correspond to the humanized description.
There are many historical examples of dehumanization. Almost every armed conflict is not complete without propaganda using this classic technique, examples of such propaganda from the beginning of the middle of the 20th century, produced during the civil and second world wars in Russia, can be cited as an example. There is a clear pattern of creating an image of an enemy with signs of a dangerous animal, with claws and sharp fangs, or a direct comparison with hostile animals, such as a spider, which, on the one hand, should justify the use of violence, and on the other hand, reduce the level of empathy of the aggressor.
Examples of Soviet propaganda posters with dehumanization techniques. Source:
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[33]https://www.pnas.org/content/114/32/8511
What's next?
Humans are an exclusively social biological species that form complex interactions, both within groups and between them. We have an extremely high level of empathy and altruism and can learn to treat complete strangers as close relatives and empathize with someone else's grief as our own.
On the other hand, we are capable of extreme cruelty, mass murder and genocide, and we can just as easily learn to perceive our relatives as dangerous animals and exterminate them without experiencing moral contradictions.
Balancing between these two extremes, our civilization has repeatedly experienced both flourishing and dark periods, and with the invention of nuclear weapons, we have never come closer to the verge of complete mutual destruction.
And although this danger is now perceived more routinely than at the height of the confrontation between the superpowers of the United States and the USSR, the catastrophe itself is still real, which is confirmed by the assessment of the Doomsday Clock initiative, in which the world's leading scientists estimate the likelihood of a global catastrophe in the format of time before midnight. And since 1991, the clock has been steadily approaching the fatal mark, reaching a maximum in 2018 and still showing “two minutes to midnight” [34].
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Fluctuations in the minute hand of the Doomsday Clock project as a result of various historical events, more about which can be found on the Wikipedia page:
The development of science and technology inevitably creates crises, out of which new knowledge and technologies are required, and it seems that we have no other way of development than the path of knowledge. We live in an amazing time on the threshold of breakthroughs in technologies such as quantum computers, fusion energy and artificial intelligence - technologies that can take humanity to a whole new level, and how we take advantage of these new opportunities will be decisive.
And in this light, it is difficult to overestimate the importance of research into the nature of aggression and cooperation, because they can provide important clues in finding answers to questions crucial for the future of humanity - how can we curb our aggression and learn to cooperate on a global scale in order to expand the concept "mine" for the entire population, not just individual groups.
Thank you for attention!
This review was written under the impression and in many respects using the materials of the lectures "The Biology of Human Behavior" by the American neuroendocrinologist, Professor Robert Sapolsky, which were read by him at Stanford University in 2010. The full course of lectures was translated into Russian by the Vert Dider project and is available in their group on youtube channel .
And for a better immersion in the topic, I recommend that you familiarize yourself with the list of references for this course, in which everything is very conveniently sorted by topic: docs.google.com/document/d/1LW9CCHIlOGfZyIpowCvGD-lIfMFm7QkIuwqpKuSemCc
Source: habr.com