The coevolution of selfish memes and human psychology

Biologists and social scientists have long argued that some ideas, beliefs, and behavior spread because such ideas are adapted to and manipulate human psychology. These "memes" may evolve to spread at the expense of the human psychology that makes them possible. However, many scholars are equally skeptical of the meme concept, suggesting that human genes keep memes on a rather short leash. Unfortunately, there are so far no formal models of these arguments. Here I present my first attempts to mathematically model the coevolutionary dynamics of social learning and parasitic behavior. These first models are exceedingly simple, but like most simple models, they are still able to surprise us. I find that selfish memes can readily invade a population of socially learning organisms and, on short time scales, can impose substantial fitness costs on the population. However, coevolution between psychology and behavior on longer time scales is equally important.