Game theory explanation of political tribalism
https://thehill.com/opinion/campaign/3550198-political-tribalism-and-the-prisoners-dilemma/
Political tribalism describes the behavior of people who value loyalty and support of a certain political tribe over any other principles. This effect is increasingly common in America’s political climate as the population becomes significantly more polarized toward specific political parties. As a result of this polarization, the ideology of these parties becomes more and more “fringe” as these parties move towards their respective political extremes (both left and right). With this in mind, a temping assumption would be that many people who do not agree with fringe ideology would simply leave their party affiliation, cross over to the opposing party, or create their own group that fits a more centrist ideology. In fact, this yearning for a more centrist political position, among the Democratic Party in specific, is evident in President Joe Biden’s recent polling. The actions taken by the Biden administration are considered heavily leftist, earning low approval ratings from an increasingly centrist population. Switching to the Republican Party, creating a more moderate party, or leaving the voting process entirely makes significant sense. However, due to political tribalism, these events are rare and unlikely.
The result of this behavior is rooted in the idea of the prisoner’s dilemma and game theory. The prisoner’s dilemma is a very specific application of game theory where each party has the option to cooperate with the authorities or to defect and sell out the other party. However, this situation is not just limited to two prisoners, but to situations where there is a significant loss (highly-negative payout) from cooperation when the other party defects on both sides. In the prisoner’s dilemma, the dominant strategy is to defect since cooperation could incur a very significant loss. A similar situation can be modeled in terms of political parties. In this case, defection would involve staying with your internal moderate values and switching to the other party. Similarly, cooperation would involve you defecting your moderate values and sticking to the party you are already affiliated with.
In this version of the prisoner’s dilemma, player A is the person affiliated with a certain political party, and player B is their current political party. Assume a payout of 0 for cooperating when the other party defects, -1 for cooperating when the other party cooperates, -4 for defecting when the other party defects, and -10 for defecting when the other party cooperates. Defection for a person in this case would mean betraying your current political party and switching over, while cooperation would mean staying with the current party. Defection for both parties is especially bad since it would mean being viewed as a traitor to either the affiliated voters (from the side of the political party) or to the political party (from the side of the voter). Thus, these values are chosen to represent that fact. Since cooperation ends up having a significantly lower cost overall, it is chosen as the dominant strategy. As a result of this dominant strategy, people are more likely to cooperate and thus exhibit political tribalism.