The Prisoner's Dilemma, Tit-for-Tat, and Game Theory | Robert Sapolsky | EP 390

Added: Oct 24, 2023

Sapolsky emphasizes that just as there is an intrinsic logic to the evolution of an organism's physiology, there is also an intrinsic logic to the evolution of behavior. The logic of behavior is shaped by evolutionary exigencies and is built around optimizing actions based on the optimal time to do something and when to do the opposite. Sapolsky introduces the concept of the "shadow of the future," which refers to the anticipation of future consequences and the role it plays in shaping behavior.

The conversation then delves into the concept of the Prisoner's Dilemma, a classic example in Game Theory. In the Prisoner's Dilemma, two individuals must decide whether to cooperate or betray each other. The optimal strategy depends on the number of rounds in the game and whether the number of rounds is known or unknown. Sapolsky explains that if the number of rounds is known, the logical choice is to never cooperate. However, if the number of rounds is unknown, cooperation becomes a viable strategy.

Sapolsky discusses the groundbreaking work of Robert Axelrod and W.D. Hamilton, who conducted a tournament using different strategies in the Prisoner's Dilemma. The simplest and most successful strategy was "tit-for-tat," which involves starting with cooperation and then mirroring the opponent's previous move. This strategy outperformed more complex algorithms and won the tournament. Sapolsky highlights that this strategy is based on forgiveness and reciprocity, as it punishes betrayal but forgives and returns to cooperation if the opponent does the same.

The conversation then explores the variations and modifications of tit-for-tat. Sapolsky explains that in real-world scenarios, straight tit-for-tat may not be enough, and additional factors such as shared culture and multi-situational games come into play. He also discusses the dangers of signal errors, where a perceived betrayal may actually be a mistake or miscommunication. Forgiveness based on prior history and the building of trust are crucial in mitigating signal errors.

Sapolsky raises concerns about the virtualization of interactions and its potential to collapse the system of trust and reciprocity. He suggests that virtual interactions lack the multi-situational games and face-to-face interactions that allow for the testing of reciprocity and trust. This virtualization also enables psychopathic manipulators who can exploit the system without reputation tracking.

The conversation then shifts to the emergence of honest and trusting societies. Sapolsky acknowledges that the default response among immature individuals, such as two-year-olds, is not cooperation. However, as the brain matures, the capacity for shared games and cooperation emerges. He discusses the initiation of low-risk trading games as a way to build trust between societies. These games involve leaving valuable items in a neutral zone, allowing the other party to take them and reciprocate with their own items.

Sapolsky continues by highlighting the importance of faith and sacrificial risk in building trust and cooperation. He suggests that the presumption of humanity on the other side and the willingness to take small risks are crucial in initiating honest and trusting interactions.

Dr. Sapolsky then addresses the central question of how to jumpstart cooperation in a world full of backstabbers. He suggests that one way to initiate cooperation is through incremental increases in investment and risk-taking. He also mentions the concept of founder populations in evolutionary biology, where isolated populations develop a high degree of cooperation and then join the general population, outcompeting others until they also adopt cooperative behavior.

The conversation then shifts to the role of religion in promoting cooperation. Dr. Sapolsky discusses the story of Abraham and the covenant, which promises that his descendants will outnumber others if they abide by a sacrificial principle. He suggests that this narrative may be a representation of the tit-for-tat reciprocal altruistic motif, where sacrificing in the present leads to future rewards for oneself and future generations. He also mentions the work of Sam Harris in grounding morality in objective fact, but argues that game theory provides a more fruitful approach to understanding cooperation.

The discussion delves into the role of dopamine in reward and reinforcement. Dr. Sapolsky explains that dopamine not only signals reward but also reinforces the neural structures involved in predicting and achieving rewards. He emphasizes that dopamine is particularly involved in the anticipation of future rewards, as it reinforces the integrity of the predictive system. He provides examples of experiments with rats and monkeys that demonstrate how dopamine levels increase when a reward is anticipated, rather than when it is actually received.

Dr. Sapolsky further explores the concept of anticipation by discussing intermittent partial reinforcement. He explains that when rewards are unpredictable and only received intermittently, dopamine levels increase even more. This is because the uncertainty and novelty of the situation signal the possibility of discovering even greater rewards in the future. He also mentions the potential for manipulating dopamine levels through the design of slot machines, where almost winning can be more reinforcing than actually winning.

The conversation then connects the concepts of dopamine and anticipation to the maturation of the prefrontal cortex and the emergence of long-term strategies. Dr. Sapolsky suggests that the ability to sacrifice immediate gratification for future rewards is a sign of maturity and is associated with the development of the prefrontal cortex. He also discusses the relationship between sacrifice and cortical maturation, highlighting the importance of sacrificing the present for the future in order to maximize adaptive strategies.

The podcast continues with a discussion on the relationship between sacrifice, maturation, and the emergence of the hero archetype. Dr. Sapolsky suggests that the hero is someone who not only masters unknown territories but also distributes the rewards obtained through reciprocal interactions. He also mentions the role of play in reinforcing exploratory behavior and its connection to the dopamine system.

Dr. Sapolsky continues by explaining the prisoner's dilemma, a classic game theory scenario where two individuals must decide whether to cooperate or betray each other. He discusses the different strategies that can be employed in this situation, including tit-for-tat, which involves reciprocating the other person's actions. He highlights the importance of trust and reputation in determining the success of these strategies.

The conversation then shifts to the cultural differences in attitudes towards cooperation and generosity. Dr. Sapolsky notes that some cultures punish generosity, viewing it as a sign of weakness or manipulation. He describes this as a form of pathological retribution, where individuals are punished for being overly generous. He suggests that this behavior is often seen in societies with high rates of child bullying, spousal abuse, and substance abuse.

The discussion then delves into the concept of dopamine and its role in anticipation and reward. Dr. Sapolsky explains that humans have a wide range of pleasures and rewards, from simple pleasures like smelling a flower to more complex rewards like solving mathematical problems. He emphasizes the importance of the dopamine system in resetting the gain and allowing for the pursuit of new rewards.

Dr. Sapolsky also explores the idea of limitation and how it can lead to creativity and exploration. He discusses the role of arbitrary limitations in enhancing creativity and the human tendency to habituate to rewards. He suggests that the constant pursuit of new rewards and experiences is what drives human beings to invent and create.

The conversation then turns to Dr. Sapolsky's research on baboons and their behavior. He explains that baboons are a perfect model for studying stress and social behavior because they exhibit similar patterns of psychosocial stress to humans. He describes how stress affects their health and immune systems and how social rank and affiliation play a role in their behavior.

Dr. Sapolsky shares an interesting case study of a baboon troop that experienced a shift in behavior due to a tuberculosis outbreak. The aggressive and unsocialized males were wiped out, leaving a more cooperative and peaceful group. He explains that this transformation occurred within a single generation, highlighting the malleability of baboon culture.

The conversation concludes with a discussion on the vulnerabilities and limitations of cooperative behavior. Dr. Sapolsky suggests that cooperation can be initiated through unique circumstances, such as the removal of aggressive individuals or the presence of self-selecting individuals. He also emphasizes the importance of cultural transmission in maintaining cooperative behavior.