December 22, 2024

Us vs Them: What Drives Prejudice?

Do Prejudice, Bias, Opposition, Antagonism have an evolutionary basis? Tribalism

Feautred Image courtesy: Max Pixel.net

Hey folks,

This Fun Fact is about why humanity divides itself into groups of “us” versus “them,” and how prejudice can emerge based on those divisions.

Over the history of human civilization, life has tended to improve for the average person. You’ll notice that rates of education, literacy, and life expectancy have gone up, while infant mortality and violent crime rates have gone down (Figure 1). Despite this, however, it often seems like things are getting worse. In some ways, they are. People are more divided now than they have been in recent history (Figure 2).

Figure 1. Society is improving in many ways.
Figure 2. In the US, Democrats and Republicans are more ideologically divided than in the past.

Over the course of evolution, living organisms have evolved methods of cooperation and altruism to help them survive in an environment with limited resources (Figure 3). Altruistic behavior is not unique to animals. Even bacteria growing in a petri dish can sacrifice themselves for the benefit of others; in particular, bacterial cells can initiate their own death if they become infected with a virus, in order to stop the virus from spreading.[1]

Figure 3. Living organisms have evolved methods of cooperation and altruism to help them survive in an environment with limited resources
Figure 4. Cooperation and altruism, combined with competition for limited resources, can lead to conflict between groups within the same species

However, cooperation and altruism can be a double-edged sword: when environmental resources are limited, cooperation can lead to competition between different groups of individuals (Figure 4).

Consider our closest living relatives in the primate world – the chimpanzee. Some of the many behaviors that they share with us include:
• Social hierarchy (patriarchal)
• Ritualistic behavior (rain dance, waterfall dance)
• Hunting with spears
• Patrolling the perimeter of their territory, violently fighting intruders [2]
• Typically less aggressive to female strangers [3]
• Group cohesion and bias towards out-groups: Males typically attack as a group, targeting victims that are isolated or outnumbered, and in most cases, attackers and victims belong to different social communities [3]

Since individuals often have to make sudden decisions in the face of uncertainty, and since those decisions can have massive consequences that involve either cooperation or competition, we have evolved a tendency to make behavioral and social decisions in a somewhat consistent, predictable way. This forms the basis of something called Error Management Theory, and it goes something like this: Suppose you are a primate living in Africa a long time ago. You come across a stranger and you recognize they are a member of your species (Figure 5). What do you do? Before you know what to do, it might be good to have some expectations about what could happen. Broadly speaking, you could have two basic expectations: this stranger will be either aggressive or non-aggressive toward you. If your expectation is “aggressive,” and you behave accordingly (by keeping your distance or by preparing to defend yourself, for example), and the reality is that they are aggressive, then you have prepared appropriately for the situation. If your expectation is “aggressive” but they turn out to be non-aggressive, then you have made a false-positive error (by falsely expecting that something is positively the case). If your expectation is “non-aggressive,” but they turn out to be aggressive, then you have made a false-negative error (this is the most dangerous one, since it maximizes the likelihood that you will be the victim of a surprise attack).

Figure 5: Social organisms constantly have to make decisions that have consequences, in the face of uncertainty

Error Management Theory basically describes the consequences of these kinds of situations in terms of natural selection. In other words, since making the more costly error reduces the likelihood of surviving and reproducing, social creatures have evolved a cognitive bias: the tendency to default toward making the kinds of errors that are estimated to be less costly towards the self.[4] This means that at least part of the reason for mental shortcuts is that they help us navigate the world and make snap decisions with limited information, in a way that we expect will most reliably help avoid the most costly outcome. One such mental shortcut is the feeling of disgust itself.[5] Feelings of disgust can help people survive by helping them avoid costly outcomes. After all, if you don’t want to touch the gross thing, you are less likely to get sick.

Unfortunately, these mental shortcuts (or heuristics) have more consequences than helping us avoid diseases…
Go back to the example of the two primates, but instead of you and a stranger in a tree, it’s your home country and a population of refugees fleeing a war zone. The same principle applies. We are innately conditioned to make hasty judgments as if we were living in a world where we don’t have access to things like facts and statistics. Not only do we lump people into groups of “us” and “them” and treat people differently based on whether they belong to “us” or “them,” but we are inherently conditioned to do this.

Henri Tajfel was a Polish Jew who fought for the French in World War 2, lost friends and family to the Holocaust, and who eventually dedicated his life to the social sciences, and in particular, the study of group prejudice.

Figure 6. Henri Tajfel fought for the French in World War 2, lost friends and family to the Holocaust, and eventually dedicated his life to the the study of group prejudice

Tajfel performed an experiment with school-age boys, in which he divided them up into arbitrary groups and then assigned them the task of distributing rewards and penalties to other participants in the study. Based on the distribution of rewards and penalties, the boys tended to behave more fairly toward members of their in-group and were more discriminatory toward members of the “other” group, even though these groups were assigned based on arbitrary, meaningless criteria.[6]

More recent studies have also reported that prejudice can exist based on “minimal” (arbitrarily defined) group affiliation.[7]

Obviously, this information cannot undo any loss of life that has occurred due to prejudice. But it is my hope that being aware of such prejudice, and why it exists, can help make things better for future generations. Be mindful of not only how you feel about other people, especially those who are different from you in some group-related way, but also be mindful of WHY you feel that way, and whether you might be taking a mental shortcut.

Thank you for reading.

References
[1] Chopin MC, Chopin A, Bidnenko E. Phage abortive infection in lactococci: variations on a theme. Curr Opin Microbiol. 2005;8(4):473-479.
[2] Amsler SJ. Energetic costs of territorial boundary patrols of wild chimpanzees. Am J Primatol. 2010;72(2):93-103.
[3] Wilson ML, Boesch C, Fruth B, et al. Lethal aggression in Pan is better explained by adaptive strategies than human impacts. Nature. 2014;513(7518):414-417.
[4] Johnson DDP, Blumstein DT, Fowler JH, Haselton MG. The evolution of error: error management, cognitive constraints, and adaptive decision-making biases. Trends Ecol Evol. 2013 28(8):474-481.
[5] Curtis V, de Barra M, Aunger R. Disgust as an adaptive system for disease avoidance behavior. Philos Trans R Soc Lond B Biol Sci. 2011;366(1563):389-401.
[6] Tajfel H. Experiments in intergroup discrimination. Scientific American. 1970;223(5):96-102.
[7] Dunham Y, Baron AS, Carey S. Consequences of ‘minimal’ group affiliations in children. Child Dev. 2011;82(3):793-811.

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