The paper examines the incidence of minor physical anomalies (MPAs) in 42 normal junior high Ss, 24 kindergarten Ss in a middle class district, 52 status and misdemeanor delinquents, 70 adolescent psychiatric patients, 32 learning disabled children, and 10 autistic children. MPAs included facial asymmetry, epicanthal folds, and geographical or fissured tongue. Analysis of complete blood chemistries and neuropsychological examinations revealed that MPAs varied significantly among the groups surveyed. The value of each of the blood measures as predictors of acting out behavior was enhanced by its association with the number of MPAs. Normal junior high and kindergarten Ss had fewer MPAs than all others studied; status and misdemeanor delinquents had fewer MPAs than psychiatric patients and learning disabled or autistic Ss. Autistic Ss had more MPAs than all the other groups. (CL)