Understanding Social Behavior in Personal Relationships Using Evolution and Game Theory
Many relationships include situations where there is manipulation and preferential interaction that MIT researchers have reported using Bayesian game theory. They use the envelope game to see these manipulation and preferential interaction behaviors in relationships. In this unequal envelope game, each player has a payoff but the first player’s actions determines the second player’s payoff. Player 1 decides whether to look inside envelope that could contain a low or high value and then he/she decides whether to cooperate or defect. If Player 1 chooses to cooperate, then both players get a payoff, otherwise Player 1 gets a payoff and Player 2 gets a loss. Player 2’s only choice is to keep going or quit the game. Player 1 obviously has more power in this situation due the fact that they decide whether to defect or cooperate. Player 2 has a little power in the sense that they can choose to continue the game or quit despite Player 1’s decision. In addition to the payoffs, each player’s choice affects the other player’s strategy. For example, Player 2’s choice to continue or end the game will influence Player 1’s next move. A Nash equilibrium, a concept we learned in class, is reached when a set of strategies for both players reaches a state where neither player will benefit by going with another strategy in the set. In particular, the envelope game has a Nash equilibrium in which choosing to look in the envelope plays a huge role. The MIT researchers also noticed that another mechanism was affecting the decision results and played a huge role in the Nash equilibrium. Player 2 can use the manipulation mechanism of threatening to end the game if Player 1 looks in the envelope. But the researchers pointed out, that this does not happen in real life because uncertainty is always there, even if one thinks they know a person really well. Taking account this uncertainty, the researchers turned this game into a Bayesian game.
A researcher found that if Player 1 always acts the same way, Player 2 can use manipulation as the only way to make looking even matter in the game. This would punish Player 1 and restrict them for any future gains, and prevents any future losses for Player 2. A mathematical formula that was ran through a model was used to simulate games and strategies to come to this conclusion. This formula is called a replicator equation, and this is where the evolutionary biology comes in. An example brought up in the article, was that there could be population with people having different strategies. Those with more successful strategies, will have more children and more likely take over the population. The equation is used to describe this survival of the fittest concept as well as cultural evolution, making it a good tool to analyze human behavior in relationships. Since there are infinite possible strategies in the envelope game, the tool can prove that a certain strategy is efficient and optimal despite the existence of all the other strategies. If the replicator equation deems a strategy optimal in any decision in a game, then it is the best response, and potentially part of the Nash equilibrium.
The mathematical model represents personal interactions where manipulation and preferential interaction exist. Researchers found that preferential interactions can give rise to an effect of more involvement of a relationship or the less interaction with the other in a relationship, depending on the other person’s decision to act. For example, in the envelope game, if Player 1 chooses to cooperate, the other player will prefer them to cooperate without looking into the envelope because they are reliable. But if Player 1 chooses to defect, then the other player will prefer them defect while looking, because they could be unreliable.
This model in the study helps us understand why people trust others who don’t look at their personal losses and gains before deciding whether to agree to do something. It helps explain why humans tend to value principled and morally thought out behavior rather than strategically calculated decisions of how to respond or act. These conclusions to the studies conducted by the MIT researches use game theory models and evolutionary process models to understand this specific aspect of social behavior among humans.
Source Article: https://news.mit.edu/2017/using-evolutionary-dynamics-game-theory-to-understand-personal-relations-0105