Fragile X syndrome (FXS) is characterized by both social approach and social avoidance. However, the age of emergence and developmental trajectory of social avoidance has not been examined. This study investigates the longitudinal developmental trajectory and dynamic nature of social avoidance in males with FXS from infancy through young adulthood…

This volume brings together leading authorities from multiple disciplines to examine the relationship between brain development and behavior in typically developing children. Presented are innovative cross-sectional and longitudinal studies that shed light on brain-behavior connections in infancy and toddlerhood through adolescence. Chapters…

Comments on Thelen and Ulrich's monograph in this issue. Examines theoretical and empirical sections and findings, concluding that the authors have taken a major step forward by introducing the dynamic systems perspective to the study of behavioral coordination in infants, thus opening the way for experimental investigation of phenomena that could…

The purpose of this study was to longitudinally examine the development of anticipatory visual search and to find out the effects of preceding experiences upon the search during the second year of life. The sample consisted of 18 Japanese firstborn nonretarded children from middle-class families who were individually tested at 11, 12, 14, 16, 22,…

To document movement patterns and to examine developmental interrelationships, the ontogeny of rooting, lip, lateral tongue, mouth opening, biting, and Babkin reflexes and the development of emerging chewing behaviors were observed in two normal infants over a period from 1 week to 35 weeks of age. (Author/RH)

Sequences of mastery behavior were analyzed in a sample of 67 infants 6 to 12 months old. Authors computed (a) frequencies of six categories of mastery behavior, transitional probabilities, and z scores for each behavior change, and (b) transitions from a mastery behavior to positive affect. Changes in frequencies and similarity in organization…

Visual behavior of infants was assessed with multiple discrimination tasks week to week from four to seven months of age. Task to task reliability was low, but attentional averages from week to week were reliable. Generally, infants with shorter fixations showed more novelty preferences, and infants' shift rate improved with age. (SKC)

Studied the ontogeny of walking by prelocomotor infants. Results support a dynamic systems view of development and the view that upright locomotion emerges from the self-organization of multiple cooperating elements rather than as a result of a preexisting neural code. (Author/GR)

This report summarizes preliminary results from a behavioral study of 13 male infants who were ascertained to have an XX Y sex chromosome complement at birth and who are being followed longitudinally through early ontogenesis. (CM)

This interim report is part of a longitudinal study of developmental behavior designed to determine whether infants from culturally disadvantaged homes have different developmental patterns than infants from advantaged homes. Twenty six culturally disadvantaged infants were individually evaluated on the Bayley Scale of Infant Mental and Motor…

Adopts a longitudinal design to track mother-child developmental change in infant task-related mastery and concomitant maternal behavior. Finds that, as infants gain more mastery across time, mothers gradually withdraw support in terms of concrete, specific and nonverbal means of instruction. Results support a one-step-ahead model for maternal…

Reports on development of a model for studying communicative competencies using naturalistic observations of specific behaviors. Discussion focuses on ways mothers and toddlers train each other to be successively more effective in their relationships. (ED)

This paper is designed as an information guide for those persons responsible for rearing human infants from birth to 18 months. The author provides an extensive review of the literature and trends of research in this area noting that the current volumes of knowledge in this area are not yet dependable enough to provide reliable bases for practice.…

Using a longitudinal design, investigates the interactive behaviors of mothers of normal infants and mothers of infants who are known to differ on a host of cognitive, behavioral, and biological parameters. Examines the developmental course of emotional expressivity in these infants. (HOD)

This article reviews 46 experimental studies on behavioral and developmental outcomes associated with prenatal exposure to illicit drugs. Only half of the 460 individual outcomes significantly indicated adverse effects of prenatal exposure. The greatest number of these outcomes was for infants younger than one month, with relatively few outcomes…