Behave – Robert Sapolsky [Book Summary]

by Nick

Robert Sapolsky’s book by Stanford professor, author of “Psychology of Stress” is striking in its courage and breadth: its purpose is to understand what affects human behavior.

Focusing on the phenomenon of violence, the author explores the factors that motivate him, and distributes them on a time scale: first, those that act a second before our act, then those that act a few minutes, then the count goes on hours, days, and even centuries. His focus is on human and animal biology, psychology, anthropology, sociology (in particular crime statistics) and history.

Sapolsky’s peculiar style is shown on every page: strictly scientific reasoning is animated by witty comments and excursions to various fields. Someone will consider that these “lyrical digressions” clarify the author’s ideas, and someone on the contrary, that they only divert to the side.

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The book’s author states that everyone is ambivalent about violence. Many are convinced that violence against those who deserve to be punished is fair. Motives of violence pervade our culture – take at least the military metaphors that are used at every step: we “cross swords” and “call for arms”. However, if force is used contrary to ethical standards, most people condemn it. To understand the nature of violence, you have to cross the boundaries of scientific disciplines more than once, but you need to start with the human brain.

“Brain Macro Organization”

The structure of the brain can be arbitrarily represented in the form of three layers.

Layer 1 is the oldest part of the brain that has appeared in reptiles. Layer 2, the limbic system, exists in all mammals. Layer 3 – the cerebral cortex, which arose later than the rest of the departments; only primates have it. All levels of exchange information. Layer 1 controls automatic functions.

The limbic system, which is responsible for emotions, contacts both layer 1 and the cortex, which is responsible for analytical thinking and management functions. To understand behavior, it is also important to know how a region of the brain called the amygdala functions. The tonsil is responsible for feelings of fear and anxiety, reaction to signals of pain and aversion, it stimulates nervous excitement and motor activity.

“This book is about how people do harm to each other. But at the same time it also tells about the exact opposite: how people know how to behave kindly. ”

The Summary you might like: Primed to Perform

In the brain, there is a constant interaction of emotions and thoughts. The bark is not able to “veto” spontaneous emotional reactions, so we often act under the influence of impulses. Signals, external and internal, enter the brain in a continuous stream. People receive many signals from each other, especially the face and eyes.

In the fractions of a second, for example, we determine the race of a person. The brain constantly receives internal signals about the state of the body: what hurts, where it is warm or cold. As for verbal information, it matters to us how it is formulated: sometimes it’s enough just to name an action with another word so that people behave differently.

Chemical Processes

Our behavior is influenced by hormones and neurotransmitters. When we do something nice, dopamine is released in the body. If we get a reward twice as much as expected, then the portion of dopamine also increases.

Once you get used to something nice, your dopamine levels are reduced. Actions for which a reward cannot be predicted, such as gambling, cause a more powerful release of dopamine than actions with a predictable reward. The dopamine level jumps sharply if you manage to successfully complete some risky business. Testosterone increases impulsiveness and risk appetite. Hormones such as oxytocin make us more “prosocial”, but only in relation to “ours”.

“It makes no sense to single out“ biological ”aspects in behavior as opposed to, say,“ psychological ”or“ cultural ”. They are intimately intertwined and interconnected. ”

Before we take any important step, we experience stress, which is why we often make the wrong decisions. However, it is necessary to distinguish between short-term and chronic stress. Short-term stress encourages us to act and can even be fun. Chronic stress triggers ongoing processes in the tonsil; Thus, information about the causative agents of fear is translated into long-term memory, and it is already difficult to get rid of fear.

By succumbing to such positive feedback cycles that enhance the response to the stimulus, we become more vulnerable to stress. Lingering stress weakens the ability to soberly assess, especially new information, and reduces social activity. Predisposed to aggression can become more aggressive under stress.

Children and Teens

As children grow older, their feelings, thoughts, and actions become more complex. At the “sensorimotor stage”, which children go through in the first two years, their attention is focused on what they can directly perceive. At the age of three to four years, the turning point is the realization that others have different thoughts and feelings.

After seven years, children develop logical thinking. As you grow older, a sense of justice develops, and with it the ability to understand how you can and how you can not act. Moral standards also have their stages of formation: first, the child proceeds from the fact that he “will be for it”, then begins to obey the rules, and later resorts to other, more complex reasonings.

The frontal cortex matures much later than the rest of the brain. In adolescence, the work of the brain, in particular, memory, become more effective. Teenagers are prone to risky behaviors and more than adults, they feel the need to belong to a social group.

Family, Cultural and Biological Factors

The conditions in which the child grows forms a model of behavior in adulthood. In childhood, the values of the culture to which it belongs begin to be assimilated. A key role in shaping human behavior is played by his mother. From it, the child receives both the necessary physical care and emotional support, which is important for the proper development and functioning in society. “Adverse childhood conditions” is the cause of antisocial adult behavior. Strong and constant stress caused by domestic violence changes the course of development of the child. If children experience hunger, humiliation, the indifference of parents, are subjected to violence or become witnesses, then this affects both the development of their brain and the ability to feel attachment. It’s not only the parenting style that affects the child,

“Cruelty does not want to be placed on any lists. And the difficulty with her is that sometimes she is a clear evil, and sometimes we have nothing against her. ”

Educational methods and game features depend on culture. There are two main types of cultures – collectivist and individualistic. In an individualistic culture, people tend to stand out, their identity is based on personal achievements. In a collectivist culture, social connections and an understanding of the point of view of other people are more important. These landmarks determine cultural values. The propensity for collectivism or individualism has its roots in the geography and method of food production: for example, if rice cultivation requires significant collective efforts, then raising sheep or goats requires individual responsibility. Compared to other forms of society, higher mobility is characteristic of nomadic peoples engaged in cattle breeding. ability to self-organize the group, “cult of honor”, blood feud and authoritarian style of education. Echoes of these traditions can be found in their descendants, leading to a different lifestyle.

“Hormones … do not produce a behavioral act. Instead, they make us more susceptible to social stimuli in emotionally significant situations, reinforcing behavioral tendencies and predispositions. ”

Cultures also vary in the nature of resource allocation. Hunter-gatherers, both ancient and modern, are more prone to egalitarianism, in part because they have virtually no property. With the development of agriculture, a stratification of society arose: individuals accumulated more property and transferred their wealth to children, thus exacerbating inequality.

Mutual trust is more characteristic of representatives of egalitarian cultures that have more powerful social capital, and people who have grown up in an atmosphere of inequality generally treat each other worse. Social stratification leads to violence, the reasons for which are lack of trust and a sense of injustice.

“The most important thing for understanding the connection between genetics and culture is the delayed maturation of the frontal cortex: the genetic program allows the evolutionarily young frontal cortex … to enable the environment and cultural norms to play the role of a sculptor.”

People’s behavior also depends on population density. Urban life is changing people at the biological level, and most importantly, these changes affect the brain. The tonsil in a city dweller responds more strongly to stress than in a villager. Residents of cities are more inclined to innovations. Citizens are constantly confronted with strangers, with whom they are not bound by blood ties: in the process of development of civilization, norms have developed that regulate the interaction between strangers.

Outbreaks of violence are caused not so much by population density as by its diversity and the nature of the territorial distribution of various groups. Clear boundaries between autonomous groups reduce violence. In a crisis, people come together, but lengthy trials, such as hunger, poverty or environmental disasters, weaken the cohesion of society. Interaction is also influenced by factors such as climate: for example, clearly changing seasons, create conditions for joint long-term planning in agriculture.

“Neither testosterone, nor alcohol, nor the media reinforce aggression. They only increase the susceptibility of aggressive people to social triggers associated with it. ”

Scientists are trying to establish whether character traits and behaviors have genetic roots. Some link behavior with genes, others, on the contrary, believe that such an approach is pseudoscientific and generates prejudice. In fact, the degree of influence of genes depends on external factors.

The specificity of the environment can lead to the fact that a particular gene will either be always “on” or always “off”. There are traits of character and behavior that genetics influence more noticeable than others. Evolution, which forms physical and behavioral traits, is aimed at the survival of an individual, not a group. In the process of “sexual selection”, evolution selects traits that attract the opposite sex, and in the process of “natural selection”, traits that increase the body’s ability to survive.

Each individual seeks to achieve maximum reproduction and, in its actions, gives preference to relatives whom it is able to recognize (mice, for example, recognize relatives by smell, and birds – by voice). Meanwhile, representatives of many species tend to cooperate with individuals belonging to other family clans. In a group, it is easier for them to ensure personal security – such as, for example, fish hatching in schools.

Collaboration Strategies

Since the 1940s, game theory scholars have been trying to find the best strategies for individual collaboration with strangers. Experiment participants are encouraged to try out different strategies in different scenarios, such as the classic “prisoner dilemma”. Common to all games is that none of the participants knows anything about the others. An optimal mutually beneficial strategy called “an eye for an eye” was proposed by the mathematician Anatole Rapoport.

Its essence boils down to the fact that in the first round of the game you need to cooperate, and then repeat – what the enemy did. With such a strategy, in comparison, say, with the strategies of exploitation or lack of cooperation, potential losses are minimal. However, such a strategy does not work if, as it happens in the real world, there is a failure in the transmission of information; signals from the other side are not correctly interpreted.

In order for cooperation to start in a large group, at least two of its members should want this and they should have a symbol that allows them to recognize each other. Then there is hope for the spread of “reciprocal altruism”.

Social Relationships

People divide those around them into friends and foes; praise their own, and defame strangers. When they see someone in someone, they are more likely to trust him, they collaborate with him and share information. They will help their own sooner rather than the strangers in trouble, it’s easier to forgive their own if he has ruined us.

We are convinced that by harming strangers, we help our group. Aliens appear to be a uniform group, foreign and threatening us. It happens that someone from others causes sympathy, but this is perceived more as an exception than as an occasion to reconsider the attitude to the whole group.

People strive both with convictions and actions to correspond to their group. When the majority disagrees with them, it causes them anxiety, and to fit into the group, they are ready to change their behavior, reconsider their beliefs and interpretation of events.

“We build cultures on speculative concepts about the meaning of life and are able to transmit these beliefs through generations, even if they have been separated by millennia.”

A social hierarchy “establishing unequal access to limited resources” is beneficial to individuals, not groups. Social inequality is captured by the brain from an early age.

The hierarchy directly affects the behavior of children: the greater the stratification of property, the more frequent are cases of bullying in groups of children.

Moral Principles

Do we comprehend what is right and what is not – or just feel it?

In general, we, of course, reflect on a moral choice, but we often make a conclusion about the admissibility of an action spontaneously and cannot explain it. Scientists note the presence of fundamental moral principles – such as justice and sympathy – in animals and children, although neither of them is capable of complex reasoning.

In adults, principles and judgments may vary depending on the culture, situation, and whose behavior is being evaluated (we are more tolerant of our own than of others). Moral principles are inseparable from empathy and compassion: the desire to help someone is caused by the fact that we feel his pain. There are several levels of empathy. The simplest is “sensory-motor infection” when we, for example, we see the tightrope walker and stretch out our arms to maintain balance. Empathy has an emotional aspect (we feel like others) and a cognitive aspect (we perceive the world as others). The pain of people who are pleasant to us or whom we perceive as ours, we feel more acutely.

Moral principles imply not the only sympathy – they encourage the transition from feelings to actions.

Conceptual Models

We are endowed with rich and complex metaphorical thinking, but the brain mixes literal and figurative meanings. Call someone disgusting – and immediately activates the area of the brain responsible for physical disgust. Someone’s resume attached to a massive folder gains more “weight” and metaphorically.

“To hit someone, you don’t need a lot of mind. But you need a complex, receptive brain to learn the situations appropriate to a given culture in which this stroke would be considered an acceptable action. ”

Religion is “the most powerful catalyst for our best and worst behavior.” Religion helps people in difficult situations, but at the same time it splits humanity into friends and foes. Throughout history, all religions have led to violence and huge sacrifices. Religion makes people more hostile to representatives of other groups, but the clash between these groups is not so dramatic if there is a great distance between them and if they have common preconditions for reconciliation. If the clash of opponents occurs in such conditions when they can interact positively, they manage to get along in a short time.

“As we can see, people are able to kill or throw themselves under bullets because of pictures, a banner, clothes or a song. And that requires an explanation. ”

Striving for peace is rational in itself, but people act irrationally and fight. However, they are disgusted at killing their own kind. Examples from zoology and history show that whole large groups change their behavior under the influence of circumstances, and sometimes under the influence of a strong personality.


  • The attitude of people towards violence is complex and contradictory.
  • To understand the motives of our behavior, an interdisciplinary approach is required.
  • The study of human behavior must begin with the brain.
  • The cerebral cortex is not able to control spontaneous emotional reactions, so we often act under the influence of impulses.
  • Thinking and emotions are constantly interacting.
  • Behavior is continuously influenced by both external and internal signals entering the brain.
  • Under the influence of chronic stress, people predisposed to aggression become more aggressive.
  • Models of behavior are formed in the process of education, and the mother plays the main role in it.
  • Cultural norms determine the behavior of people centuries after the circumstances that gave rise to them.
  • A person divides others into friends and foes.

Why You Should Read “Behave”

  • To learn what lies behind people’s decisions
  • To find out what separates good from evil
  • To dig deep in human psychology and behavior patterns

This book is available as:

Audiobook | eBookPrint