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…

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…

How do young children direct their attention to other people in the natural world? Although many studies have examined the perception of faces and of goal-directed actions, relatively little work has focused on what children will look at in complex and unconstrained viewing environments. To address this question, we showed videos of objects,…

We examined two aspects of temperamental approach in early infancy, positive reactivity and anger, and their unique and combined influences on maternal reports of child surgency and attention focusing at 4 years of age. One hundred and fourteen infants were observed for their positive reactions to novel stimuli at 4 months, and their anger…

Two preferential-reaching experiments explored 5- and 7-month-olds' sensitivity to pictorial depth cues. In the first experiment, infants viewed a display in which texture gradients, linear perspective of the surface contours, and relative height in the visual field provided information that two objects were at different distances. Five- and…

Halberda (2003) demonstrated that 17-month-old infants, but not 14- or 16-month-olds, use a strategy known as mutual exclusivity (ME) to identify the meanings of new words. When 17-month-olds were presented with a novel word in an intermodal preferential looking task, they preferentially fixated a novel object over an object for which they already…

Infants (n = 24, mean age 13 months and n = 24, mean age 19 months) were tested on an extension of the method introduced by Tomasello and Haberl (2003) to examine the understanding of another person's interest in a novel object. Four objects were presented serially. For two objects, infants played with an experimenter. The infant played with one…

The relations among infant anger reactivity, approach behavior, and frontal electroencephalogram (EEG) asymmetry, and their relations to inhibitory control and behavior problems in early childhood were examined within the context of a longitudinal study of temperament. Two hundred nine infants' anger expressions to arm restraint were observed at 4…

Like faces, bodies are significant sources of social information. However, research suggests that infants do not develop body representation (i.e., knowledge about typical human bodies) until the second year of life, although they are sensitive to facial information much earlier. Yet, previous research only examined whether infants are sensitive…

Behne, Carpenter, Call, and Tomasello (2005) showed that 9- to 18-month-olds, but not 6-month-olds, differentiated between people who were unwilling and unable to share toys. As the outcome of the two tasks is the same (i.e., the toy is not shared), the infants must respond to the different goals of the actor. However, visual habituation paradigms…

This study examined both differential patterns and the stability of infants' (N = 70) distress reactivity across mother and stranger arm-restraint conditions when infants were 6 and 9 months of age. Reactivity measures included observational variables for the rise, intensity, and duration of infant distress as well as motor activities associated…

Four experiments investigated infants' preferences for age-appropriate and age-inappropriate infant-directed speech (IDS) over adult-directed speech (ADS). Two initial experiments showed that 6-, 10-, and 14-month-olds preferred IDS directed toward younger infants, and 4-, 8-, 10-, and 14-month-olds, but not 6-month-olds, preferred IDS directed…

People often express excitement to each other when encountering an object that they have shared together previously in some special way. This study investigated whether 14-month-old infants know precisely what they have and have not shared in a special way (and with whom). In the experimental condition an adult and infant shared an object (the…

When are the precursors of ordinal numerical knowledge first evident in infancy? Brannon (2002) argued that by 11 months of age, infants possess the ability to appreciate the greater than and less than relations between numerical values but that this ability experiences a sudden onset between 9 and 11 months of age. Here we present 5 experiments…

Previous studies have shown that 7.5-month-olds can track and encode words in fluent speech, but they fail to equate instances of a word that contrast in talker gender, vocal affect, and fundamental frequency. By 10.5 months, they succeed at generalizing across such variability, marking a clear transition period during which infants' word…