HIGH RESPONSE THRESHOLD ON THE LOVIBOND-RAPAPORT OBJECT SORTING TEST IN THE PARENTS OF SCHIZOPHRENICS

McConaghy (1959, Journal of Neurology, Neurosurgery and Psychiatry, 22, 243-246) reported that parents of schizophrenic patients showed associative "loosening" measured by the Lovibond-Rapaport Object Sorting Test (OST). Most studies that attempted to replicate this finding produced data showing statistically non-significant trends in the predicted direction. The present study explored the possibility that significant group differences have been obscured because parents of schizophrenics may make fewer responses on the OST, thereby lowering their total OST scores. Total OST scores of 23 parent-pairs of schizophrenic patients were compared with those of 19 parent-pairs of healthy controls. As in most earlier studies, parents of schizophrenics showed a non-significant trend to have raised OST scores. They also responded to significantly fewer items on the OST, i.e. showed high response threshold, compared with the parents of healthy controls. The parents of schizophrenics had significantly higher OST scores than healthy controls when the number of OST items not responded to was partialled out. It is suggested that future studies using the OST determine if the parents of schizophrenics show high response threshold and control for this effect if present.