Research on sources of individual difference in parental Infant-Directed Speech (IDS) is limited and there is a particular lack of research on fathers' compared to mothers' speech. This study examined the predictive relations between infant characteristics and variability in paternal lexical diversity (LD) in dyadic free play with two-year-olds (M…

Aimed to establish extent to which toddlers' social behaviors in recurrent play groups may become characterized by an increased consistency and predictability during second year of life, particularly first versus third trimester. Concurrent observations in contrasting settings provided data for examining differences in extent of cross-situational…

The reliability and validity of three measures of infant temperament were compared in this study. The measures included the revised Carey (1978) Infant Temperament Questionnaire, a version of the Bayley (1969) Infant Behavior Record revised for completion by the parent, and a modified version of Buss and Plomin's (1975) EASI, an acronym standing…

Factor analysis of 25 rating scales from Bayley's infant behavior record were performed for a sample of about 300-400 infant twins tested one or more times between 3 and 24 months of age. The analyses provided five major and two minor factors that were considerably consistent at all ages. (Author/DB)