(My upcoming paper)
Although diseases like Schizophrenia can be a hugely debilitating mental disorder, which has been proved to have a genetic basis, it has been present in the human race for a long time and instead of slowly dying out, as would be expected of a disease with a genetic basis, it is still believed to be growing at a remarkably fast rate, currently affecting roughly 1% of the worlds population.
'Schizotypy' is an embryonic form of Schizophrenia, in which the affected person possesses some of the symptoms of the Schizophrenic Spectrum, like a tendency to non conformity and unusual experiences, they do not display certain other traits like introversion, affective disorders, an inability to find pleasure in everyday situations, or avolition. As a result of this they lead fairly normal lives, although they share some mental tendencies with Schizophrenic personalities. Recent studies by have found that these individuals have a tendency to greater creativity, which in turn has been shown to lead to greater mating success. This would explain why we continue to have Schizophrenia in society, because a milder variant, which could then occur amongst close relatives of affected individuals, will lead to greater mating success.Other articles:
Schizotypy, creativity and mating success in humans - Daniel Nettle, Helen Clegg (Full article, PDF)
The creative process: A phenomenological and psychometric investigation of artistic creativity - Christopher Barnaby Nelson (Full article PDF)
Creativity and mental illness: Prevalence rates in writers and their first degree relatives - Nancy C Andreasen (Full article PDF)
Natural selection and schizophrenia - Roger J Sullivan, John S Allen (Abstract)
Pic: Syd Barrett