• The development of infants born to parents with serious mental disorders was followed up from birth through the first year of life. An individual-differences approach to statistical analysis, Multidimensional Scalogram Analysis (MSA), was shown to be an effective statistical procedure for examining heterogeneous psychiatric populations. The MSA revealed the existence of a subgroup of infants born to schizophrenics who repeatedly performed poorly in motor and sensorimotor areas of functioning during their first year of life. These infants were especially vulnerable to external insults, and many had low to low-normal birth weights. These findings, taken together with similar findings from other investigations, add support to the hypothesis that these infants may have a genetically determined neurointegrative deficit.