Dr Sapolsky explores schizophrenia to see if there is any hidden adaptive advantage in the condition as there are with so many other genetic disorders. Disorders where the full maladapted trait is extremely harmful to the individual but where a lower partial level of the same trait clearly has adaptive benefits.
Harvard psychiatrists undertook an extensive study of over 10 000 families in Denmark, speaking with the largest number of schizophrenics and their families ever, and over the period of a decade they noticed something quite remarkable. The family members, the biological relatives of the schizophrenics displayed a very high incidence of schizotypal characteristic behaviour, differing from the full schizophrenia where life is at times impossible, these characters instead were withdrawn and had a strong tendency towards metamagical thinking.
They were the type of characters to be obsessed with science fiction fantasy or new age beliefs that were so extreme they took things to another level, taking things to be very literal. Typically the religiously leaning schizotypal accepts the seven day creation story, not as metaphorical, but as fact. The same with the resurrection, not symbolic of continued life or anything, it actually happened. Schizotypal personality traits as a mild form of schizophrenia is a recognised diagnosis.
Robert Raven an anthropologist first highlighted this schizotypalism with the shamans and witch doctors, medicine men and women of so called primitive civilizations and religious beliefs. Extreme behaviour, speaking to the dead, talking in tongues and all the other strange and not so wonderful behaviours attached to religion. The characters with the full blown schizophrenia, provided the balance was right, were and are highly regarded members of society.
I think you can see where this is leading, from the pages of the National Geographic magazine to our own societies and those who invented theology were schizotypal/schizophrenic personalities. The main tenets of religion are very closely related to obsessive compulsive disorders, rituals, cleanliness. It's a superb lecture and very interesting.