As an important part of the plan to record and systematically deal with all observable behavioral events that constitute an infant's waking life, all social encounters between the baby and other persons that occurred during weekly observations of two infants in their everyday milieu were recorded. (Author/CB)

Researchers in the fields of cognitive and language development have made less use of large-scale longitudinal designs and of person-centered approaches to data analysis than have researchers in the fields of social and personality development. It is argued that differences among domains of developmental psychology in the research methods employed…

Used a longitudinal sibling research design and a large, nationally representative sample of 15- to 22-year-old siblings to study shared and unshared environmental influences on delinquency. Although no unshared family environmental influences were found for sisters and mixed-sex siblings, they may have existed for brothers. Data suggested…

This longitudinal study examined consistency and change in human personality. Rather than studying the consistency of individual differences over time, an approach which considers only the stability of a variable at the group level and ignores differences in stability at an individual level, this study used a person-centered approach to study…

Applied a person-centered approach to childhood personality development in 28 diverse samples of 3- to 6-year-olds studied over 6 years. Identified resilient, overcontrolled, and undercontrolled personality types. Found that the undercontrolled personality type related to intellectual decline over 6 years. The number of family risks predicted…