Temperament development was studied in 39 full-term small-for-gestational-age infants and 30 full-term appropriate-for-gestational-age infants. Temperament was measured at 4, 8, and 12 months of age using a behavioral assessment procedure and questionnaire ratings. Findings indicated that restricted fetal growth negatively affects infant temperament development, and that the severity of growth retardation is associated with magnitude of developmental deviancy. (Author/TJQ)