We investigate when infants exhibit knowledge of the familiar size of well-known objects and whether this knowledge is affected by stimulus format, that is, whether the stimuli are presented as real objects or matched pictures. Infants (130 7- and 12-month-olds) saw everyday objects such as sippy cups and pacifiers in their familiar size and novel…

Infants' responses to male and female faces and their preferences for happy versus fearful faces were studied to extend findings indicating that infants at 7 months can generalize discrimination between expressions of happiness and surprise across four different female models' faces. In the first experiment, a paired-comparison procedure was used…