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…

Faces are visually attractive to both human and nonhuman primates. Human neonates are thought to have a broad template for faces at birth and prefer face-like to non-face-like stimuli. To better compare developmental trajectories of face processing phylogenetically, here, we investigated preferences for face-like stimuli in infant rhesus macaques…

Previous research has demonstrated infants' capacity to discriminate between situations in which all the objects successively hidden behind a screen are present, or not, after the removal of the screen. Two types of interpretation have been proposed: counting capacity or object memorization capacity. In the usual paradigm, the missing object in…