Conceptual impairment in the parents of poor-premorbid male schizophrenics was investigated with the Object Sorting test. Twenty-one parent pairs of the patients and 16 parent pairs of normal young men were studied. Although scores for patient-fathers indicated greater impairment than those of control fathers, this was not statistically significant.
Patient-fathers' impairment scores did exceed patient-mothers' to a greater extent than control fathers' exceeded control mothers'. The confirmation of the father-mother impairment hypothesis can support the notion that within families of poor-premorbid male schizophrenics conceptual adequacy is sex-typed in favor of females.