Schizophrenia-spectrum risk alleles may persist in the population, despite their reproductive costs in individuals with schizophrenia, through the possible creativity benefits of mild schizotypy in non-psychotic relatives. To assess this creativity-benefit model, we measured creativity (using 6 verbal and 8 drawing tasks), schizotypy, Big Five personality traits, and general intelligence in 225 University of New Mexico students. Multiple regression analyses showed that openness and intelligence, but not schizotypy, predicted reliable observer ratings of verbal and drawing creativity. Thus, the ‘madness-creativity’ link seems mediated by the personality trait of openness, and standard creativity-benefit models seem unlikely to explain schizophrenia's evolutionary persistence.
The evolutionary origins of schizophrenia spectrum disorders can illuminate their hidden adaptive costs and benefits, guide the search for genetic and environmental risk factors, and suggest new interventions (Keller and Miller, 2006 and Shaner et al., 2004). Following millennia of controversy about the ‘madness–creativity’ link (see Becker, 2000, Lauronen et al., 2004 and Sass, 2000), some current models (e.g. Andreasen, 1987, Crow, 2000, Eysenck, 1995 and Nettle and Clegg, 2006) suggest that schizophrenia-spectrum risk alleles may persist in current human populations through the possible creativity (and hence reproductive) benefits of mild schizotypy in non-psychotic relatives, which may counter-balance their severe reproductive costs in individuals with schizophrenia (Avila et al., 2001 and Haukka et al., 2003).
Many studies have shown positive relationships between schizotypy and creativity among creative professionals (Burch et al., 2006a, Merten and Fisher, 1999 and Nettle and Clegg, 2006), normal young adults (Cox and Leon, 1999, Folley and Park, 2005, Rushton, 1990, Schuldberg, 2000, Tsakanikos and Claridge, 2005 and Weinstein and Graves, 2002), and non-psychotic relatives of schizophrenics (Andreasen, 1987, Karlsson, 1984 and Kinney et al., 2000). However, schizotypy might not predict creativity after controlling for other heritable traits that have better-established associations with creativity, such as general intelligence (Eysenck, 1995, Jensen, 1998, Kuncel et al., 2004 and Rushton, 1990) and the personality trait of ‘openness’ from the Big Five model (Carson et al., 2005, Dollinger et al., 2004, King et al., 1996, McCrae, 1987, Wolfradt and Pretz, 2001 and Zhang and Huang, 2001). To investigate the possible role of such confounds, we administered the SPQ measure of schizotypy (Raine, 1991), diverse verbal and drawing creativity tasks, and standard intelligence and personality measures to a diverse sample of normal young adults from a state college.
