The Evolution of Right and Wrong

MICHELLE Avataneo is a Visiting Assistant Professor at the Instituto Tecnológico Autónomo de México (ITAM). Prior to joining ITAM, she obtained her PhD in Managerial Economics and Decision Sciences from Northwestern University. Her research uses evolutionary game theory to study the origins of moral behaviour.

The Confluence: How did you first get drawn to using evolutionary game theory to study morality?

Dr. Avataneo Truqui: It was by luck. During my PhD, I became interested in evolutionary game theory. For one of my classes, I wrote a research proposal on using evolutionary game theory to think about optimal immigration policies.

Around the same time, I wanted to work as a research assistant for a professor I really admired, so I emailed him. He asked what I was interested in, and I told him evolutionary game theory. He had been reading Jonathan Haidt’s work on moral foundations, which argues that there are five moral foundations everybody has, and these five foundations have an evolutionary basis. We decided to work together on modelling Haidt’s five moral foundations and using evolutionary game theory to figure out if indeed they have an evolutionary basis.

The Confluence: What’s the biggest misconception people have about modelling moral behaviour mathematically? Doesn’t assuming people are optimising strip out anything “moral” about it?

Dr. Avataneo Truqui: I don’t think it does. I think of morality as something that can lead people away from the behavior that would maximize their biological fitness. For example, imagine that a certain action would be best for me in terms of resources, energy, or survival. I may still choose something else because I care about the person I am interacting with, or because I care about being fair.

In our models, those moral concerns become part of what the person values. So the person is still “optimizing,” but she is not necessarily optimizing biological fitness. She may willingly sacrifice some of her own fitness because behaving morally is itself valuable to her. Thus, we are not modeling morality as a duty that forces people to act against what they want; instead, we model morality as part of what they want.

The interesting question then becomes: why do people develop these moral motivations, and under what social conditions do different kinds of morality survive evolutionary pressures? We think of individuals with higher biological fitness as being more likely to reproduce and pass their moral preferences on to their children. This creates a puzzle: if morality can lead people to choose actions that do not maximize their biological fitness, how can such moral preferences evolve and persist in the first place?

The Confluence: What’s the most surprising or counterintuitive finding from your research on how cooperation or moral norms emerge, without assuming people are either purely selfish or purely altruistic?

Dr. Avataneo Truqui: One of the main findings of my research is that the type of morality that emerges from an evolutionary process depends on the kinds of social interactions that are common in a society. I distinguish between two types of morality: universalism and particularism.

Universalists apply the same moral standards to everyone; for example, they may be equally caring toward members of their own group and outsiders. Particularists, by contrast, apply moral standards differently toward their in-group and out-group.

I found that universalist moralities tend to be favoured by evolution when interactions are mostly one-off, as is more common in large, anonymous societies such as cities. Particularist moralities, in contrast, tend to be favoured when interactions are repeated and people expect to encounter the same individuals again, as is more common in smaller or more tightly knit communities.

The Confluence: Is there a real-world example where evolutionary game theory predicted cooperation succeeding or breaking down in a way that surprised you?

Dr. Avataneo Truqui: In my research, I find that cooperation with strangers is more likely to succeed in environments where interactions are mostly one-off, such as cities and market settings. This happens because the moral types that are evolutionarily favored in those environments tend to be universalists, and universalists are more willing to cooperate with people outside their own group.

There is empirical research consistent with this prediction: people in cities tend to cooperate more with strangers than people in rural areas, and greater exposure to markets has also been associated with more cooperation toward strangers.

What makes this surprising is that a standard intuition in economics is that cooperation is easier to sustain when interactions are repeated: if I expect to meet you again, I have an incentive to cooperate today because my behaviour will affect how you treat me tomorrow. That logic is correct when people’s preferences are taken as fixed and assumed to lack morality.

However, once we allow evolution to select among moral types, the prediction changes. Morality itself is evolutionarily advantageous, but different environments favour different kinds of morality. Universalism tends to be favoured in one-off interactions, while particularism tends to be favoured when interactions are repeated. Because universalists are more willing to cooperate with strangers, this makes cooperation with strangers more common in environments where interactions are less repeated.

The Confluence: What’s one thing you wish people understood better about where moral norms actually come from?

Dr. Avataneo Truqui: That our moral intuitions did not emerge in a vacuum. They developed in social environments in which the way we treated other people affected our ability to survive, reproduce, and function within groups.

What I find particularly interesting is that there may not be one type of morality that is best in every environment. Different patterns of social interaction can favour different morals. So rather than thinking of morality as something completely separate from the environment in which people live, I think we should ask how particular social environments helped shape the moral motivations that we experience.