Journal article

Phenotypic and genetic analyses of a short measure of psychosis-proneness in a large-scale Australian twin study.

DA Hay, NG Martin, D Foley, SA Treloar, KM Kirk, AC Heath

Twin Research | Published : 2001


Previous genetic analyses of psychosis proneness have been limited by their small sample size. For the purposes of large-scale screening, a 12-item questionnaire was developed through a two-stage process of reduction from the full Chapman and Chapman scales. 3685 individuals (including 1438 complete twin pairs) aged 18-25 years and enrolled in the volunteer Australian Twin Registry returned a mail questionnaire which included this psychosis proneness scale and the Eysenck Personality Questionnaire. Despite the brevity of the questionnaire, item and factor analysis identified four unambiguous and essentially uncorrelated scales. There were (1) Perceptual Aberration--Magical Ideation; (2) Hypo..

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