Schizotypy is a multidimensional personality construct representing the extension of psychosis-like traits into the general population. It has been associated with attenuated expressions of many of the same neuropsychological abnormalities as schizophrenia, including atypical functional segregation. Previous studies have been inconsistent in their findings of a relationship between schizotypy and laterality, with some research indicating that schizotypy is associated with increased right-hemisphere advantage, some with increased left-hemisphere advantage, and some with bilateral increased or decreased activation. The present thesis hypothesises that this inconsistency could result from methodological issues with the studies, such as the use of different scales and lateralized tasks between studies, and failure to control for sex differences in laterality. The present studies therefore compared, within-participants, two common self-report measures of schizotypy (the O-LIFE and the Chapman scales) and three different lateralised tasks, as well as testing for sex differences. In addition, the influence of other non-controlled
potential moderators of the schizotypy-laterality relationship was assessed, on the basis that different expressions of high schizotypy (adaptive versus maladaptive, and 'genuine' high schizotypy scorers versus false positives), moderated by participants' religious beliefs, might relate differentially to lateralised task performance. None of the experimental manipulations resolved the conflict in previous findings, or moderated a relationship between schizotypy and laterality. Findings indicated that either 1) no relationship exists between schizotypy and laterality, or less likely 2) that a relationship does exist, but is subtle, complex, and fluctuating, making it extremely difficult to assess. Based on the findings as a whole, it is recommended that adaptive schizotypy, and especially religious belief, should be taken into account in any studies of schizotypy and neuropsychology. Additionally, the O-LIFE scale is suggested to provide a more reliable measure of schizotypy than the Chapman scales, particularly in student samples.