Children vary in the extent to which their development is shaped by particular experiences (e.g. maltreatment, social support). This variation raises a question: Is there no single level of plasticity that maximizes biological fitness? One influential hypothesis states that when different levels of plasticity are optimal in different environmental…

When speaking to young children, adults adapt their language to that of the child. In this article, we suggest that this child-directed speech (CDS) is the result of a transactional process of dynamic adaptation between the child and the adult. The study compares developmental trajectories of three children to those of the CDS of their caregivers.…

Children (N = 157) 4 to 8 years old participated 1 time (single) or 4 times (repeated) in an interactive event. Across each condition, half were questioned a week later about the only or a specific occurrence of the event ("depth first") and then about what usually happens. Half were prompted in the reverse order ("breadth first"). Children with…

In longitudinal studies data is collected in a series of waves. Each wave after the first suffers from attrition. Therefore it can be difficult to discriminate between changes in sample parameters due to a longitudinal process (e.g. ageing) and changes due to attrition. The problem is particularly vexing if one of the purposes is to compare…

A quantitative model of speech development is proposed based on observations of normal hearing and congenitally deaf children. Nonlinear controls used during the development of suprasegmental and segmental aspects of speech are identified. Linguistic components of speech are ignored. The importance of the associative cortex in speech-motor control…

A theory of the dynamics of dyadic interaction is presented, based on the concepts of "concern" (i.e., intentions, goals, and interests), "appraisal" and "contagiousness." Differences between children who participate in a specific interaction are linked to differences in social competence and social power. An overview is given of the social…

The review indicates that refined measures of the family environment and the use of complex statistical models increase the understanding of the relationships between socioeconomic status, sibling variables, family environment, and cognitive development. (RC)

The developmental trend from overall-similarity to dimensional-identity classifications is explained by a quantitative model. The model provides good qualitative fits to the extant data. Three experiments examining classifications in 120 2- to 8-year-olds and in 20 undergraduates support specific new claims of the model. (TJH)

A meta-analysis of research on the relationship between inspection time (IT) and IQ was performed. The analysis was designed to determine whether a non-zero relationship between IT and IQ exists, estimate the size of this relationship, and test whether IT is ontogenetically related to "g" (intelligence). (TJH)

This article discusses issues in measuring lexical diversity, before outlining an approach based on mathematical modelling that produces a measure, D, designed to address these problems. The procedure for obtaining values for D directly from transcripts using software (vocd) is introduced, and then applied to thirty-two children from the Bristol…

Stochastic difference equations of the Box-Jenkins form provide an adequate family of models on which to base the stochastic theory of human growth processes, but conventional time series identification methods do not apply to available data sets. A method to identify structure and parameters of stochastic difference equation models of human…

In this article we explore young children's development of mathematical knowledge and reasoning processes as they worked two modelling problems (the "Butter Beans Problem" and the "Airplane Problem"). The problems involve authentic situations that need to be interpreted and described in mathematical ways. Both problems include tables of data,…