Infants Discriminate the Affective Expressions of their Peers: The Roles of Age and Familiarization Time.

Research examining infants' discrimination of affect often uses unfamiliar faces and voices of adults. Recently, research has examined infant discrimination of affect in familiar faces and voices. In much of this research, infants were habituated to the affective expressions using a "standard" 50% habituation criterion.

Dynamics of infant habituation: infants' discrimination of musical excerpts.

Schöner and Thelen (2006) summarized the results of many habituation studies as a set of generalizations about the emergence of novelty preferences in infancy. One is that novelty preferences emerge after fewer trials for older than for younger infants. Yet in habituation studies using an infant-controlled procedure, the standard criterion of habituation is a 50% decrement in looking regardless of he ages of the participants.

To Grasp or Not to Grasp: Infants' Actions Toward Objects and Pictures.

We conducted two experiments to address questions over whether 9-month-old infants believe that objects depicted in realistic photographs can be picked up. In Experiment 1, we presented 9-month-old infants with realistic color photographs of objects, colored outlines of objects, abstract colored "blobs," and blank pages. Infants most commonly rubbed or patted depictions of all types.

Infants' discrimination of happy and sad music.

Infants can detect information specifying affect in infant- and adult-directed speech, familiar and unfamiliar facial expressions, and in point-light displays of facial expressions. We examined 3-, 5-, 7-, and 9-month-olds' discrimination of musical excerpts judged by adults and preschoolers as happy and sad. In Experiment 1, using an infant-controlled habituation procedure, 3-, 5-, 7-, and 9-month-olds heard three musical excerpts that were rated as either happy or sad.

Experimenter Affective Expression and Gaze Following in 7-Month-Olds.

The study of gaze following in infants younger than 12 months of age has emphasized the effects of gesture, type of target, and its position or placement. This experiment extends this literature by examining the effects of adults' affective expression on 7-month-olds' gaze following. The effects of 3 affective expressions-happy, sad, and neutral-on 7-month-olds' frequency of gaze following were examined.

Matching and naming objects by shape or function: age and context effects in preschool children.

Three experiments tested preschoolers' use of abstract principles to classify and label objects by shape or function. Three- and 4-year-olds were instructed to match objects by shape or function. Four-year-olds readily adopted either rule, but 3-year-olds followed only the shape rule.