Having one's funding cut in the course of conducting a longitudinal study has become an increasingly real challenge faced by developmental researchers. The main purpose of the current work is to propose "post hoc" planned missing (PHPM) data designs as a promising solution in such difficult situations. This study discusses general…

Cultural transmission is often viewed as a domain-general process. However, a growing literature suggests that learnability is influenced by content and context. The idea of a learnability landscape is introduced as a way of representing the effects of interacting factors on how easily information is acquired. Extending prior work (Barrett &…

This commentary endorses J. Kagan's (2008) conclusion that many of the most dramatic findings on early perceptual, cognitive, and social competencies are ambiguous. It supports his call for converging research operations to disambiguate findings from single paradigms and single response indices. The commentary also argues that early competencies…

This report presents data on 9-month-old twin pairs (n[MZ]=172; n[DZ]=333) from the Early Childhood Longitudinal Study, demonstrating that the role of genetic variation among infants is trivial and the shared and nonshared environment is substantial in accounting for the observed quality of infant-caregiver relationships. In contrast, maternal…

Explaining new ideas to oneself can promote transfer, but how and when such self-explanation is effective is unclear. This study evaluated whether self-explanation leads to lasting improvements in transfer success and whether it is more effective in combination with direct instruction or invention. Third- through fifth-grade children (ages 8-11;…

Number sense development of 411 middle- and low-income kindergartners (mean age 5-8 years) was examined over 4 time points while controlling for gender, age, and reading skill. Although low-income children performed significantly worse than middle-income children at the end of kindergarten on all tasks, both groups progressed at about the same…

In this study of the origins of individual differences in theory of mind (ToM), the Environmental Risk (E-Risk) Longitudinal Twin Study sample of 1,116 sixty-month-old twin pairs completed a comprehensive battery of ToM tasks. Individual differences in ToM were striking and strongly associated with verbal ability. Behavioral genetic models of the…

Continuity in relationship representation and developmental links between relationship representation and behavior from infancy to late adolescence were examined using longitudinal data from a risk sample (N185). Significant correlations were found among diverse representational assessments (e.g., interview, drawing, projective narrative) and…

Highlights three longitudinal studies examining the hypothesis that attachment security during infancy influences individual differences and adult representations of attachment. Notes that attachment security was significantly stable in two studies, with discontinuity in all three studies related to negative life events and circumstances.…

Interviews were conducted with 336 mother--child dyads (children's ages ranged from 6 to 17 years; mothers' ages ranged from 20 to 59 years) in China, India, Italy, Kenya, the Philippines, and Thailand to examine whether normativeness of physical discipline moderates the link between mothers' use of physical discipline and children's adjustment.…

Using data from 5,070 youth ages 11 to 18 years old who participated in the National Longitudinal Study of Adolescent Health, concurrent and longitudinal associations among cumulative risk, protective factors, and youth maladjustment were examined. Cumulative risk was associated with concurrent conduct problems and depressed mood. For conduct…

Children's lead and pesticide exposures are used as examples to examine social disparities in exposure reduction efforts as well as environmental policies impacting children in poverty and minority children. The review also presents an estimate of the effect of social disparities in lead exposure on standardized test performance. Because including…