Explored genetic and environmental underpinnings of temperamental differences in 3- to 16-month-old twins and their parents. Found that additive genetic and shared environmental effects best represented smiling, laughter, and duration of orienting. Shared environmental effects fully accounted for co-twin similarity for soothability. Additive…

Examined role of infant and toddler temperament in predicting 2-year olds' empathy. Found that children showed relatively more concern for mother's distress, but were also responsive to unfamiliar victims. Unreacting infants showing little affect also showed less empathy toward the unfamiliar adult almost two years later. Inhibition toward…

Examined predictive validity of measures of infant habituation and later aspects of temperament. Found babies who habituated sooner (fewer trials to criterion) at five months of age and had fewer peak fixations during habituation were rated by mothers as more active, intense, and negative in mood, and less persistent and adaptable. Age differences…

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 of nine-month olds was assessed by means of questionnaires and two laboratory visits. Mothers' and fathers' agreement on questionnaire scales was low, and their factor structures differed. In laboratory measures, fearfulness and pleasure showed cross-situation generality, short-term stability, and convergence with questionnaire scales.…