Cultural Evolution and the Value of Tradition

What the science of cultural evolution teaches us about tradition and social change.

When I was younger, I’d occasionally say something idiotic like “just because it’s been done a certain way in the past doesn’t mean we should keep doing it that way”. I might have even uttered the words “tradition is stupid” at some point. I have now become less of an idiot by reversing this attitude. The fact that something has been done a certain way for a very long time is a good reason to keep doing it that way. And tradition is not stupid. It’s much smarter than you and me. The fact that our ancestors adhered to a particular tradition and simultaneously survived/reproduced constitutes some initial evidence that the tradition has functional utility. This is not to say that we should always adhere to tradition. It is only to say that we should not deviate from tradition without having good reasons to do so. People who are temperamentally conservative (i.e., low in the Big Five trait openness and high in the Big Five trait conscientiousness) seem to implicitly get this. They naturally (and blindly) adhere to tradition. Temperamentally liberal people like me (who are high in openness and low in conscientiousness) have to learn the value of tradition the hard way. It goes against our nature. So, what changed my mind about the value of tradition? In large part, it was reading the scientific literature about cultural evolution.

The field of cultural evolution began with an insight about the way cultures change over time. It was noticed that there is a kind of selection process that determines which cultural ideas (using the word “ideas” very broadly to include technologies, dialects, fashions, songs, religions, etc.) spread and persist. This selection process means that cultures change in a way that is analogous to the way populations change genetically (hence, cultures “evolve”). Most cultural ideas die out very quickly. Others can spread rapidly through a population and persist for long periods of time. This selection process is not random. What makes a cultural idea more likely to spread and persist? There are a variety of factors involved. Some examples include:

1. Prestige bias — people copy successful people. If an admired and successful person happens to adopt an idea (a certain fashion, for example) that idea is more likely to spread in that population. The best way to understand this is to think about why Michael Jordan sold underwear. What is the correlation between being a great basketball player and being a connoisseur of underwear? There is none, of course, but that doesn’t matter. We copy successful people even outside of their domains of expertise. The logic seems to be something like: “This person is successful, but I don’t know precisely why they are successful, so I’ll just copy them across the board.” This logic leads people to subconsciously copy Michael Jordan’s underwear choices and/or dress, talk, and get plastic surgery like Kim Kardashian.

2. Conformity bias — people copy the majority. Of course, there are always those who go against the grain, but they are the exception. Most people believe what those around them believe, dress how they dress, talk how they talk, and value what they value. If you were born into a country where 99% of the people around you were Muslim, there’s a very good chance that you’d be a devout Muslim. We are natural conformists. So, once a cultural idea crosses a certain threshold and becomes adopted by a large majority, simple conformity acts like a kind of inertia, carrying that idea into the future. 

3. Cultural group selection — groups with “better” ideas outcompete groups with “worse” ideas. I put the words “better” and “worse” in scare-quotes here because I don’t mean “better” in a moral sense, or in terms of the truth of the idea. I just mean that if a particular cultural idea (e.g., an institution or social norm) causes a group to function more cohesively or efficiently such that the group is now able to outcompete its neighbors, that idea is more likely to proliferate simply because the groups that adopt it are more likely to proliferate. For example, at one point in time groups that adopted monarchies tended to outcompete other forms of social organization. Because of their extremely top-down organization, monarchies tended to be more efficient at waging war than other forms of social organization available at the time. Monarchies proliferated largely for that reason (and because cultures copy successful cultures). These days, democracies have outcompeted most other forms of organization and so democracy has proliferated in the last 100 years. Groups that adopt more functional forms of culture (defined in terms of the groups ability to outcompete other groups) outcompete groups that don’t. That’s obviously a circular explanation, but hopefully you get the point. 

These are just a few of the factors that determine what kinds of cultural ideas will survive and proliferate. What does this have to do with the value of tradition? Let me give two examples that should help to clarify my point. The first comes from the water temples of Bali. Some Balinese rice farmers have an ingenious method for managing irrigation. There is a hierarchical system of temples that ensures water is managed properly. This system comes with its own set of mythologies and rituals which, to the right-thinking modernist, may appear to be “irrational”. What could praying to the water spirits possibly have to do with proper water management? That is what the Balinese government seemed to think in the 1970s when they implemented a more “scientific” and “green” approach to agriculture, dismantling the system of temples. The result was a disaster. Pests invaded the crops and within a decade they were back to using the old system. 

The Balinese system of temples was not invented by a single person. Nobody designed it. It evolved over hundreds or perhaps thousands of years, with small changes being adopted from time to time. From our blinkered perspective, the mythologies and rituals associated with this system of agriculture may seem irrational or inefficient. And yet they may serve a real function that we do not currently understand. Either way, the attempt to design a new system from the top-down failed miserably. The tradition was better than the rational replacement. 

The second example is monogamous marriage. Joseph Henrich and colleagues published a paper in 2012 in which they put forward a potential solution to the “puzzle” of monogamous marriage. It’s a puzzle because most societies do not enforce monogamy. That is, most societies allow for polygamous marriage (one man with multiple women). The minority of societies that do enforce monogamy, however, have had massive success in terms of growth and expansion. Is the monogamy related to the growth? Henrich and colleagues say that it is. Monogamy reduces the pool of childless, unmarried men in the population. The thing about childless, unmarried men is that they tend to be a lot more violent and reckless than their domestic counterparts. The more men you can get to be married with children, the more tame your population of men becomes. Tamer men commit less crimes. Less crime means that the society functions more smoothly. Smoothly functioning societies are able to wage war more effectively and engage in expansionary practices. That’s the argument, in a nutshell. I find it convincing, but I never would have thought of it on my own. 

In both cases (Balinese water temples and monogamous marriage norms) we find a tradition that has functional utility, but is causally opaque to the people who engage in it. That is, the tradition’s causal mechanisms are not known to the people who engage in the tradition. Presumably, the people who carry out the rituals associated with the Balinese temples don’t know the precise function of those rituals. And most people couldn’t articulate monogamy’s role in promoting social stability. Despite the fact that nobody understands why they work, the traditions still have a useful social function. Blind adherence to these traditions is not irrational. It’s how we were designed. 

This causal opacity is a common feature of culturally evolved institutions. Lots of things work for reasons that we don’t understand. Unless we have a good reason to change them, we ought to leave social institutions alone. Sometimes we do have good reasons to change things. That’s definitely the case. But massive and sudden change is more likely to be destructive than creative. Look at what happened in the Soviet Union or in other communist countries when they decided to radically change the way they organize their economies. Mass starvation and privation were often the result. Tinkering is usually better than revolutionary change, even though revolutionary change is occasionally necessary. Cultural evolution gives us a scientifically grounded reason to respect tradition and to resist large and sudden changes to social institutions.