It is probably fair to say that most people are well aware of the irrational nature of superstitious beliefs – both in general and in particular – and yet many such beliefs remain firmly planted in most, if not all, societies around the world.
Given many people’s dismissive attitude towards superstition, as well as their actions which seem to nonetheless correspond to it, two theoretical biologists from the University of Pennsylvania have devised a game theory-driven model to explain how such beliefs turn into social norms.
“What’s interesting here is that we show that, beginning in a system where no one has any particular belief system, a set of beliefs can emerge, and from those, a set of coordinated behaviours,” said co-author Erol Akçay.
Using one of the solution concepts from game theory, namely correlated equilibria, Akçay and his colleague Bryce Morsky argue that such patterns emerge when people observe each other’s behaviour and infer that which is expected of them on that basis.
“A classic example is a traffic light,” explained Akçay. “If two people are approaching an intersection, one will get a ‘stop’ signal and one will get a ‘go’ signal and everybody knows that. It’s rational for both parties to obey the light.”
While, in this scenario, social interactions are mediated by the traffic light – which here constitutes a “correlating device”, to use game theoretic parlance – the researchers wanted to know whether coordinated behaviours could arise even in its absence.
In their model, Akçay and Morsky assume that individuals do not follow norms blindly, but rather try to imitate successful people’s beliefs, thereby giving rise to “competition” between a variety of different norms that eventually results in the development of new ones.
It turns out that by prescribing how people should behave and what expectations they should have of others, evolutionarily stable, i.e., non-interchangeable, norms give rise to consistent behavioural patterns even if there is no one to express or enforce them.
“What I like about this work,” said Morsky, “is that these beliefs are made-up superstitions, but they become real because everybody actually follows them, so you create this social reality. I’m really interested in testing that further.”