The drift hypothesis of mental health contends that having psychiatric conditions leads people to drift down in social ladder and to end up in lower status. This hypothesis is cited, sometimes, to explain why the elite groups seem to have better mental health compared to proletariats and underclasses. However, there is another type of drifting, stochastic drift, that may purely randomly cause traits (such as psychiatric disorders) to disappear or fully blow in small groups, and elite groups are usually small! I haven't seen this evolutionary mechanism being discussed by sociologists so far. This simulation shows that in small communities, a trait can virtually disappear or become universal purely by chance, with no selection or causal driver at all. Adjust the community sizes and starting prevalence of a hypothetical disease, then click Run Simulation.