ABSTRACT
A dysfunction of cerebral lateralisation has frequently been invoked to explain both schizophrenic symptomatology, and schizophrenia risk Studies of handedness using patient samples have yielded variable results. Some have demonstrated more sinistrality among schizophrenics. More consistent results have emerged from studies of handedness in relation to schizotypy, or so-called "psychosis-proneness", among normal subjects. One explanation of the results that has to be considered is that they reflect some trivial test-taking response set common to both the schizotypy and handedness questionnaires. A simplified and more conventional, scoring of the handedness data was also used, in which subjects were assigned to one of three categories, of left, mixed, and right. Mixed-handers who used the right or the left hand for different actions. Even investigators using more elaborate assessment procedures have generally been content with a simple three-way classification of handedness. The studies reviewed—both in clinical and normal populations—have based their classification of handedness on measuring devices of varying sophistication.
