Extralimital triradii as a putative marker of schizotypy

Abstract

Dermatoglyphic anomalies are reported to occur at a higher rate in schizophrenic patients and schizotypic individuals than in the general population, supporting the hypothesis that they are a marker of vulnerability for such conditions. Dermatoglyphic anomalies are hypothesized to indicate severe disruptions in the second trimester of prenatal development, a time period that appears to be etiologically relevant to the development of schizophrenia and related conditions. The present study provides the first examination of extralimital triradii in schizotypic young adults ( n=197) and control participants ( n=135) identified by the Revised Social Anhedonia Scale [Eckblad, M., Chapman, L.J., Chapman, J.P., Mishlove, M., 1982. The Revised Social Anhedonia Scale. Unpublished test (copies available from T.R. Kwapil, Department of Psychology, University of North Carolina at Greensboro P.O. Box 26164 Greensboro, NC 27402-6164)], the Perceptual Aberration Scale [Chapman, L.J., Chapman, J.P., Raulin, M.L., 1978. Body image aberration in schizophrenia. J. Abnorm. Psychol. 87, 399–407], the Magical Ideation Scale [Eckblad, M.L., Chapman, L.J., 1983. Magical ideation as an indicator of schizotypy. J. Consult. Clin. Psychol. 51, 215–225], and the Physical Anhedonia Scale [Chapman, L.J., Chapman, J.P., Raulin, M.L., 1976. Scales for physical and social anhedonia. J. Abnorm. Psychol. 85, 374–382]. As hypothesized, the schizotypic participants (6.6%) exhibited significantly higher rates of extralimital triradii than control participants (1.5%). These findings strongly encourage the future investigation of extralimital triradii in at-risk and psychotic populations.