From very early in life, humans can approximate the number and surface area of objects in a scene. The ability to discriminate between 2 approximate quantities, whether number or area, critically depends on the ratio between the quantities, with the most difficult ratio that a participant can reliably discriminate known as the Weber fraction.…

Research in the past decades has investigated the time course of the acquisition of physical knowledge in early development in much detail. However, few is known about the motives that actually lead infants to interact with the objects of their physical world. The research presented here investigated in two experiments if 11-month-old infants'…

Six-month-olds reliably discriminate different monkey and human faces whereas 9-month-olds only discriminate different human faces. It is often falsely assumed that perceptual narrowing reflects a permanent change in perceptual abilities. In 3 experiments, ninety-six 12-month-olds' discrimination of unfamiliar monkey faces was examined. Following…

The experiments reported here investigated the development of a fundamental component of cognition: to recognize and generalize abstract relations. Infants were presented with simple rule-governed patterned sequences of visual shapes (ABB, AAB, and ABA) that could be discriminated from differences in the position of the repeated element (late,…

Can infants use interposition and line junction cues to infer three-dimensional (3D) structure? Previous work has shown that in a task that required 4-month-olds to discriminate between static two-dimensional (2D) pictures of possible and impossible cubes, infants exhibited a spontaneous preference for displays of the impossible cube but left open…

Six experiments investigated 7-month-old infants' capacity to learn about the self-propelled motion of an object. After observing 1 wind-up toy animal move on its own and a second wind-up toy animal move passively by an experimenter's hand, infants looked reliably longer at the former object during a subsequent stationary test, providing evidence…

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…

This study examined infants' enumeration of puppet jumping tasks. In Experiment 1, 5-7-month-old infants were familiarized to a puppet jumping two or three times, and tested with both numbers of jumps. Infants looked significantly longer at the new number, replicating Wynn [Psychol. Sci. 7 (1996) 164]. To probe further the stability of infants'…