score:4
Your source might be referring to the potential link between schizophrenia, or more specifically milder versions of it, and religiosity. Cases of "possession" and "inner voices" attributed to gods and spirits that eventually led to organized religion could indeed have been mild cases of schizophrenia. The theory originates from Paul Radin in the 1930s.
Interesting lecture on the topic: Dr. Robert Sapolsky on Biological Underpinnings of Religiosity. He discusses precisely the topic you're wondering about around 12:00. There's also an interesting bit on the link between ritualism and OCD around 30:00.