Recent research suggests that 12-month-old infants use shape to individuate the number of objects present in a scene. This study addressed the question of whether infants would also rely on shape when shape is only a temporary attribute of an object. Specifically, we investigated whether infants realize that shape changes reliably indicate…

This study examines face-scanning behaviors of infants at 6, 9, and 12 months as they watched videos of a woman describing an object in front of her. The videos were created to vary information in the mouth (speaking vs. smiling) and the eyes (gazing into the camera vs. cueing the infant with head turn or gaze direction to an object being…

Means-end actions are an early-emerging form of problem solving. These actions require initiating initial behaviors with a goal in mind. In this study, we explored the origins of 8-month-old infants' means-end action production using a cloth-pulling training paradigm. We examined whether highlighting the goal (toy) or the means (cloth) was more…

Relations between maternal sensitivity and physiological reactivity to infant crying were examined using measures of heart rate (HR) and respiratory sinus arrhythmia (RSA) in 49 mothers of second-born infants. Using the Ainsworth Sensitivity Scale, an independent assessment of maternal sensitivity was made during maternal free play and bathing of…

The study of dyadic interaction plays a major role in infancy research. To advance conceptually informed measurement of dyadic interaction and integration across studies, we examined factor structure of individual parents' and infants' measures and dyadic measures from face-to-face interactions in two samples of 6-month-old infants and…

We examined how infants' categorization is jointly influenced by previous experience and how much they shift their gaze back and forth between stimuli. Extending previous findings reported by K. A. Kovack-Lesh, J. S. Horst, and L. M. Oakes (2008), we found that 4-month-old infants' (N = 122) learning of the exclusive category of "cats" was related…

Behavioral indices (e.g., infant looking) are predominantly used in studies of infant cognition, but psychophysiological measures have been increasingly integrated into common infant paradigms. The current study reports a result in which behavioral measures and physiological measures were both incorporated in a task designed to study infant number…

Most infants with more than 6 weeks of crawling experience completely avoid the deep side of a visual cliff (Campos, Bertenthal, & Kermoian, 1992; Gibson & Walk, 1960). However, some experienced crawlers do move onto the transparent surface suspended several feet above the ground. An important question is whether these "nonavoiders" lack wariness…

This study employed a new "anticipatory intervening" paradigm to tease apart false belief and ignorance-based interpretations of 18-month-olds' helpful informing. We investigated in three experiments whether 18-month-old infants inform an adult selectively about one of the two locations depending on the adult's belief about which of the two…

Newborn infants preferentially orient to familiar over unfamiliar speech sounds. They are also better at remembering unfamiliar speech sounds for short periods of time if learning and retention occur after a feed than before. It is unknown whether short-term memory for speech is enhanced when the sound is familiar (versus unfamiliar) and, if so,…

Infants' emerging ability to move independently by crawling is associated with changes in multiple domains, including an increase in expressions of anger in situations that block infants' goals, but it is unknown whether increased anger is specifically because of experience with being able to move autonomously or simply related to age. To examine…

The literature reports some contradictory results on the degree of phonological specificity of infants' early lexical representations in the Romance language, French, and Germanic languages. It is not clear whether these discrepancies are because of differences in method, in language characteristics, or in participants' age. In this study, we…

Three laboratory experiments on social referencing examined whether infants' tendencies to look at and use positive information from the experimenter could be interpreted from a perspective of novelty or expertise. In Study 1, novelty was manipulated. Forty-eight 12-month-old infants participated. In a between-subject design, a more novel or a…

Prosocial behaviors are a diverse group of actions that are integral to human social life. In this study, we examined the ability of 18- and 24-month-old infants to engage in three types of other-oriented behaviors, specifically helping, sharing, and comforting. Infants in both age groups engaged in more prosocial behavior on trials in which an…

This study explored variation in affective and behavioral components of infants' jealousy protests during an eliciting condition in which mother and an experimenter directed differential attention exclusively toward a rival. Variation was examined in relation to child temperamental emotionality, maternal interaction style, and attachment security.…