Relationships among neurological functioning, intelligence quotients, and physical anomalies

The relationships among IQ, neurological signs, and minor physical anomalies--all measures of central nervous system status--were assessed in the index and control children of the study. The strongest correlation was found between neurological functioning and IQ; the relationship between anomalies and neurological functioning was less strong; and no relationship was found between anomalies and IQ. Consistently, the most poorly functioning children tended to be offspring of schizophrenic patients (index cases), although the same children did not always perform poorly on all tests. What emerges is a set of clusters of individuals with varying combinations of functional/developmental problems.