Developmental instability and schizotypy

Introduction. It has been suggested that evidence of developmental disturba nce of cognition and lateralisation in schizophrenia can be best understood from the perspective of developmental stability (DS), an indicator of the extent to which an individual develops according to a specified ontogenic p rogramme in the presence of environmental noise. Higher levels of fluctuati ng asymmetry (FA; the difference between right and left side of a quantitat ive morphological trait such as dermatoglyphics) are thought to reflect les s DS. We examined this issue for dimensions of schizotypy. Methods. Associa tions between FA, measures of laterality and cognitive function on the one hand, and negative and positive dimensions of schizotypy on the other, were examined in a sample of 260 healthy adolescents aged 11.9-15.6 years. FA w as measured as a-b ridge count right-left differences. Neuropsychological m easures yielded a general cognitive ability score and a frontal function sc ore. Laterality was assessed with the Annett scale. Results. Measures of ps ychosis proneness were normally distributed. Negative schizotypy was associ ated with more FA and lower general cognitive ability in a dose-response fa shion. The association with FA was more apparent in boys. No associations e xisted with laterality or frontal function. Conclusion. The negative dimens ion of schizotypy may be associated with early developmental instability, r esembling the pattern seen in the negative symptom dimension of schizophren ia. Measures of fluctuating asymmetry may be more sensitive with regard to the schizotypy phenotype than measures of laterality. (C) 2000 Elsevier Sci ence B.V. All rights reserved.