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…

Relations between infant-mother attachment security at 15 months and infants' (N = 206) joint attention behaviors (a) with an experimenter at 8 and 15 months, and (b) with their mothers at 15 months were investigated. No concurrent or longitudinal relations were observed between attachment security and infants' tendency to respond to an…

What kind of featural information do infants rely on when they are trying to recognize a previously seen object? The question of whether infants use certain features (e.g., shape or color) more than others (e.g., luminance) can only be studied legitimately if visual salience is controlled, as the magnitude of feature values--how noticeable and…

Acoustic properties of the cries of 14 infants were evaluated at both 2 and 4 weeks of age when the infants were lying in a supine position and when they were sitting upright in a car seat. In the upright position, infants' breathing was more rapid and showed less individual variability. The fundamental frequency of their cries increased in the…

This study was aimed at sorting out conflicting results in the literature concerning 2-month-olds' sensitivity to interpersonal contingency, and investigated the potential role of infants' positive emotion in contingency detection. Infants were randomly assigned to an experimental group (EG) that was presented an uninterrupted live-replay-live…