Wallace's Paradox, or Why We Have Such a Large Brain. Column for Kompyuterra #105

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Dmytro Shabanov
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Unreliable instincts, or Why there are bad mothers among people The Wallace paradox, or Why we have such a large brain Why do we allow ourselves to be deceived, or Sad reflections on the irrationality of political life

{"translated_text": "←\nDmytro Shabanov\n→\n\nUnreliable Instincts, or Why There Are Bad Mothers Among Humans\nWallace's Paradox, or Why We Have Such a Large Brain\nWhy We Allow Ourselves to Be Deceived, or Sad Reflections on the Irrationality of Political Life\n\nColumn for Kompyuterra #104\nColumn for Kompyuterra #105\nColumn for Kompyuterra #106\n\nAs a result of natural selection, a savage would be endowed with a brain only slightly superior to that of a monkey, whereas in reality his brain is only slightly smaller than that of a philosopher. Thus, we can conclude that the savage possesses a brain that, with improvement and development, is capable of performing far more complex work than is usually required of it.\nAlfred Russel Wallace\n\nIn this column, I will begin discussing a problem that causes me difficulty. This difficulty is not related to Wallace's paradox itself, one of the formulations of which is given in the epigraph. In my view, satisfactory explanations for the intellectual power of our brain have been found today. What I do not understand is why the factors that so beneficially influenced our previous evolution do not have a corresponding impact on our social realities. But about this later, probably in the next column.\nAnd in this column, let us talk about Wallace's paradox. We observe modern people and see that their brain is capable of carrying out extremely complex operations that probably far exceed the complexity of the tasks our ancestors solved during our evolutionary becoming. The brain may seem redundant, and also an extremely expensive evolutionary acquisition. Roughly speaking, the brain's weight is only 2 percent of our body's weight, but it consumes 20 percent of the energy we expend — that's serious. If so, the question posed in the epigraph seems quite justified.\nIt remains to remind that the brain of the \"savage\" (a Paleolithic representative of our species) was not smaller, but larger than the brain of a modern human. The evolutionary turning point occurred somewhere 30-40 thousand years ago: until this point, brain size had been increasing in our evolutionary lineage, and after that it began to decrease! The reasons for this decrease are discussed quite convincingly. But why did the brain increase so consistently before this turning point?\nAs is known, the explanation of the properties of living beings as a consequence of evolution due to natural selection independently occurred to Charles Darwin and Alfred Russel Wallace. There is still debate about whether Darwin acted nobly with Wallace's letter to him outlining the basics of the new theory. It appears that in Darwin's most famous book, \"The Origin...,\" there were certain borrowings of Wallace's ideas. Wallace was truly noble; he is the author of the term \"Darwinism.\"\n[IMG_1]\nAlfred Russel Wallace (1823–1913), image from www.nature.com\nThe founding fathers of modern evolution diverged on the question of human origin. Both Darwin and Wallace considered humans too rational for the development of their intellect to be explained by the simple action of natural selection. Darwin attempted to explain the development of our mind using a new concept of sexual selection. Wallace preferred to state that the development of our intellect remains unexplained and its explanation requires considering additional factors.\nThe further development of evolutionary biology showed (as in many other questions) Darwin's perspicacity. However, it is still too early to definitively close the issue. When speaking of the origin of the human mind, we are describing a unique process inaccessible to direct observation and experiment. If we now have theoretical models satisfactorily describing this process, this does not mean that new, even more successful explanations will not appear in the future. My description of the accumulated views in this field will necessarily be very brief. If this topic interests you in more detail, I recommend turning to at least the second volume of Alexander Markov's two-volume work on human evolution.\nLet us consider what categories the explanations for why our huge brain evolved in our species might belong to. Of course, first of all, we must consider the possibility that the creation of a \"superbrain\" was adaptive in nature. But the environment is not something unified; it can be divided into extra-populational and intra-populational. We have said that selection can be group and individual; finally, we must not forget about sexual selection. Certain traits may develop during adaptive evolution directed not at themselves, but at some other, more or less closely related characteristics. Finally, some traits (probably only relatively simple ones) may develop simply by chance.\nThus, the possible explanations for the development of a particular trait are as follows:\n\nadaptive:\n\t\ngroup: increasing the population's survival in its environment;\nindividual: increasing the individual's chances of survival and reproduction:\n\t\t\nincreasing the individual's fitness to the environment external to the population;\nincreasing the individual's fitness to the intra-populational environment;\nincreasing the individual's attractiveness to sexual partners;\n\n\nside effect of the evolution of other traits;\n\nrandomly arising characteristic.\n\nThe last variant (random development) can be discarded. The cost of possessing an energy-intensive brain is so high that such a trait could not have developed by chance. The trend that ensured its development must have overcome selection directed at energy conservation.\nSide effect? I can believe that the ability to solve equations is a side effect of the ability to track prey by traces, but a trait like the enormous size of the brain cannot be explained by correlations within the organism. On the contrary, the increase in brain size required a deep restructuring of many other functional \"nodes\" of the organism that seemed unchangeable. For example, for the newborn's head to pass through the opening of the pelvis, a set of ad hoc solutions had to be developed, including a \"foldable\" skull in the fetus (entailing risks of brain blood supply disorders) and a \"deployable\" (opening at the pubic symphysis) pelvis in the mother, entailing risks of musculoskeletal function disorders.\nProbably, the argument related to the increasing intensity of learning in the modern social environment can be attributed to this category of explanations. We have learned to teach our children, and therefore the neurological basis that provided functions important for the \"savage\" mentioned by Wallace is now capable of solving more grand-scale tasks. In other words, during our becoming, a brain evolved with different, weaker capabilities than that characteristic of us now; the capabilities of then and now are, in general, different traits. By the way, this argument is useful for explaining the current decrease in brain size: with normal training, we have enough of it as it is.\nBut still, even with a correction for less efficient training, the large brain must be a consequence of direct adaptive evolution. Group selection will not explain it; if group selection made some contribution to the evolution of this trait, this contribution was not decisive (group selection is inevitably less powerful than individual selection). Thus, we must choose between selection for fitness to the extra-populational environment, to the intra-populational environment, and sexual selection.\nThe very paradoxicalness of Wallace's paradox is related to the fact that selection for correspondence to the extra-populational environment seems insufficient to explain the development of such a complex brain. What remains? Intra-populational and sexual selection. And here we see powerful factors that could ensure the evolution of our brain.\nLet us begin with sexual selection, the very concept of which Darwin proposed in connection with the problem of human evolution. And today we see that many women are attracted to men with high intelligence, good sense of humor, and pronounced creative abilities. Do not say that wives of smart, witty, and creative men often regret that they tied their lives to their impractical husbands rather than, for example, to boring rich men. They do regret it. But still, again and again, they fall for the tricks of smart, witty, and creative men...\nAnd also in the most different cultures, men who want to impress women begin to use more complex speech constructions than usual, as well as joke and demonstrate creative talents — ability to dance, sing, make music, write poetry, paint, etc. Do you think this is coincidence?\nWhat has been said applies to today, but we have grounds to assume that it was so earlier as well. Watch Dennis Dutton's TED lecture on the evolutionary theory of beauty. Could you have imagined that the complex and beautiful teardrop-shaped Acheulean handaxes that our ancestors made for a dizzyingly long period of time (beginning 2.5 million years ago and ending 1.4 million years ago) usually bear no traces of wear from use? So what were these handaxes made for? To show someone their extraordinary abilities. To whom? To a potential partner, more precisely, a female partner. According to Dutton, the line \"Why don't you come to my cave, I could show you my axes?!\" works great to this day.\nThere is no reason to doubt that sexual selection contributed to the complexity of human behavior that required an increase in their brain. But probably this factor was not the only one. I agree with those who consider adaptation to the intra-populational environment to be the most significant cause of our brain enlargement.\nIn the most different primitive societies, success in survival and reproduction is closely related to social status, to the result of interaction with fellow tribesmen. A characteristic feature of humans is their ability to establish individual relationships with many different people. These relationships take into account the history, personal characteristics of the counterparts, and include predicting their reactions using a model of their psyche.\n\"Primates are well aware of the variability of their social world — often even better than of the physical world. Thus, green monkeys are terrified to death of pythons but are unable to recognize a fresh python track. On the other hand, they clearly track the genealogy and history of their group. If two monkeys quarrel, their relatives will take offense and will continue to provoke each other for several more days.\" Carl Zimmer. \"Evolution. The Triumph of an Idea\"\nAn important difference in adaptation to extra-populational and intra-populational environments is that the latter is much more dynamic. If you learned to jump from branch to branch, the branches will not change because of this. If you can outplay (for example, deceive) your fellow tribesmen, you will leave many offspring who will (with a certain probability) inherit your talents. They will have to interact with each other, in a social environment that will become even more complex. This is exactly why the ecological intelligence hypothesis, linking our evolution with adaptation to the external environment, looks much less convincing than the social intelligence hypothesis.\nThus, it is intra-populational interactions that open up an almost infinite perspective of evolutionary improvement for the intelligence of individuals. The result of this evolution is the development of so-called Machiavellian intelligence (or Machiavellian intelligence) — the ability to achieve one's goals in a changing social environment. Niccolò Machiavelli, a Florentine politician and thinker of the early 16th century, earned the reputation of an amoral cynic, but was probably a very decent person. However, in his ideas about the correct way of acting, success comes first, not morality or adherence to principles. Evolution \"reasons\" the same way.\n[IMG_2]\nNiccolò Machiavelli (1469–1527), image from dudye.com\nCan one say what level of Machiavellian intelligence will be sufficient for a player seeking to outplay other Machiavellian players in a complex and changeable social environment? A model of other players' consciousness allows one to recognize deceptions; increasing perspicacity requires improving methods of deception. There is no end to such an arms race.\nThrough the work of English anthropologist Robin Dunbar, it has been shown that the size of the neocortex (the progressive part of the cerebral cortex) in primates is closely related to the size of their groups. The group size corresponding to our brain size is about 150 individuals (the so-called Dunbar number). It seems that indeed, larger groups of people do not allow individualized relationships of all their members with each other. However, 150 individualized connections is really a lot, and their maintenance requires a very complex neurological apparatus.\nHow do these connections work? They allow one to take into account the history of relations with each each tribesman, assess his reputation, transmit various information about his actions through the mechanism of rumors and gossip, and make justified forecasts about his possible future actions.\nIt is important that sexual selection and selection for Machiavellian intelligence intertwine and begin to support each other. High intelligence becomes a marker of fitness, attracting partners; carriers of this marker leave more offspring and further complicate social interactions in the population.\nAnd yet, for me, the key consequence of the explanation of Wallace's paradox described here is that the phenomenon of accounting for the individual reputation of people we know goes back to our evolutionary past, is connected with the very reason for the development of our intelligence.\nDoes the phenomenon of reputation work in modern society as one might expect?\n\n←\nDmytro Shabanov\n→\n\nUnreliable Instincts, or Why There Are Bad Mothers Among Humans\nWallace's Paradox, or Why We Have Such a Large Brain\nWhy We Allow Ourselves to Be Deceived, or Sad Reflections on the Irrationality of Political Life\n\nColumn for Kompyuterra #104\nColumn for Kompyuterra #105\nColumn for Kompyuterra #106"}

As a result of natural selection, the wild would be endowed with a brain only slightly exceeding that of a monkey, whereas in practice his brain is only slightly smaller than that of a philosopher. Therefore, we can conclude that the wild possesses a brain that, with improvement and development, is capable of performing much more complex work than is usually required of it. Alfred Russel Wallace

adaptive: group: increases the survival of the population in its environment; individual: increases the chances of survival and reproduction of an individual: increases the fitness of an individual to the external environment for the population; increases the fitness of an individual to the internal population environment; increases the attractiveness of an individual to sexual partners;

a side effect of the evolution of other traits;

a randomly occurring property.

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Dmytro Shabanov
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