Recent evidence from studies using head cameras suggests that the frequency of faces directly in front of infants "declines" over the first year and a half of life, a result that has implications for the development of and evolutionary constraints on face processing. Two experiments tested 2 opposing hypotheses about this observed…

Wynn's (1992) seminal research reported that infants looked longer at stimuli representing "incorrect" versus "correct" solutions of basic addition and subtraction problems and concluded that infants have innate arithmetical abilities. Since then, infancy researchers have attempted to replicate this effect, yielding mixed…

This research examined whether infants tested longitudinally at 10, 14, and 16 months of age (N = 58) showed evidence of perceptual narrowing based on face gender (better discrimination of female than male faces) and whether changes in caregiving experience longitudinally predicted changes in infants' discrimination of male faces. To test face…

Given the centrality of prosociality in everyday social functioning, understanding the factors and mechanisms underlying the origins of prosocial development is of critical importance. This experiment investigated whether experience with reciprocal object exchanges can drive the developmental onset of sharing behavior. Seven-month-old infants took…

Over the past few decades, there has been extensive debate as to whether humans represent number abstractly and, if so, whether perceptual features of a set such as cumulative surface area or contour length are extracted more readily than number from the external world. Here we show that 7-month-old infants are sensitive to smaller ratio changes…

Infants' motor skill development triggers changes in parent-infant interactions, exploration, and play behaviors, particularly during periods of locomotor transitions. We investigated how these transitions reorganized infants' and mothers' explorations of spatial layouts. Thirteen infants and their mothers were followed biweekly from the age of 6…

This is a longitudinal study of development in coordinated mother-infant vocal interaction from 4 to 10 months (N = 41) focusing on the development of turn-taking patterns and time spent in coordinated vocal interaction. Data analyses were carried out using multistate analysis. Both mothers and infants were found to coordinate their own…

We assessed the eye-movements of 4-month-old infants (N = 38) as they visually inspected pairs of images of cats or dogs. In general, infants who had previous experience with pets exhibited more sophisticated inspection than did infants without pet experience, both directing more visual attention to the informative head regions of the animals,…

Nouns form the first building blocks of children's language but are not consistently modified by other words until around 2.5 years of age. Before then, children often combine their nouns with gestures that indicate the object labeled by the noun, for example, pointing at a bottle while saying "bottle." These gestures are typically…

Using both traditional composites and novel profiles of anger, we examined associations between infant anger and preschool behavior problems in a large, longitudinal data set (N = 966). We also tested the role of life stress as a moderator of the link between early anger and the development of behavior problems. Although traditional measures of…

Previous studies have demonstrated that various psychosocial risks are associated with poor cognitive functioning in children, and these risks frequently cluster together. In the current longitudinal study, we tested a model in which it was hypothesized that cumulative psychosocial adversity of mothers would have deleterious effects on children's…

Communication spontaneously initiated by infants at heightened risk (HR; n = 15) for autism spectrum disorders (ASD) is compared with that in low-risk (LR; n = 15) infants at 13 and 18 months of age. Infants were observed longitudinally during naturalistic in-home interaction and semistructured play with caregivers. At both ages, HR infants…

Compared subjects' judgments about emotions expressed by the faces of infants pictured in slides to predictions made by the Max system of measuring emotional expression. Judgments did not coincide with Max predictions for fear, anger, sadness, and disgust. Results indicated that expressions of negative affect by infants are not fully…

Examined facial expressions in relation to cognition in infants 2 to 8 months of age. A total of 48 subjects received an audiovisual stimulus contingent on arm movement, whereas 32 infants did not control the stimulus. Infants in the contingent group expressed greater interest and joy during learning and greater anger during extinction. (RH)