The onset of intentional communication in children's first year of life represents a major milestone in human cognitive development. Similarly, it is well established that our closest living relatives, the great apes, communicate with signals characterized by at least first-order intentionality. Despite the well-documented influence of…

How long does it take for a newborn to recognize an object? Adults can recognize objects rapidly, but measuring object recognition speed in newborns has not previously been possible. Here we introduce an automated controlled-rearing method for measuring the speed of newborn object recognition in controlled visual worlds. We raised newborn chicks…

Niche construction is the modification of components of the environment through an organism's activities. Humans modify their environments mainly through ontogenetic and cultural processes, and it is this reliance on learning, plasticity and culture that lends human niche construction a special potency. In this paper we aim to facilitate…

Both chimpanzees and human infants use the pointing gesture with human adults, but it is not clear if they are doing so for the same social motives. In two studies, we presented chimpanzees and human 25-month-olds with the opportunity to point for a hidden tool (in the presence of a non-functional distractor). In one condition it was clear that…

Domestic dogs comprehend human gestural communication in a way that other animal species do not. But little is known about the specific cues they use to determine when human communication is intended for them. In a series of four studies, we confronted both adult dogs and young dog puppies with object choice tasks in which a human indicated one of…

McCarty and colleagues (1999) developed the elevated spoon task to measure motor planning in human infants. In this task, a spoon containing food was placed on an elevated apparatus that supported both ends of the spoon. The handle was oriented to the left or right on different trials. We presented naive adult rhesus monkeys (Macaca mulatta) with…

Newborn chicks were tested for their sensitivity to number vs. continuous physical extent of artificial objects they had been reared with soon after hatching. Because of the imprinting process, such objects were treated by chicks as social companions. We found that when the objects were similar, chicks faced with choices between 1 vs. 2 or 2 vs. 3…

When enumerating small sets of elements nonverbally, human infants often show a set-size limitation whereby they are unable to represent sets larger than three elements. This finding has been interpreted as evidence that infants spontaneously represent small numbers with an object-file system instead of an analog magnitude system (Feigenson,…

The capacity to reason about the false beliefs of others is classically considered the benchmark for a fully fledged understanding of the mental lives of others. Although much is known about the developmental origins of our understanding of others' beliefs, we still know much less about the evolutionary origins of this capacity. Here, we examine…

Infants are sensitive to biological motion, but do they recognize it as animate? As a first step towards answering this question, two experiments investigated whether 6-month-olds selectively attribute goals to shapes moving like animals. We habituated infants to a square moving towards one of two targets. When target locations were switched,…

In a previous study, Adachi, Kuwahata, Fujita, Tomonaga & Matsuzawa demonstrated that infant Japanese macaques (Macaca fuscata) form cross-modal representations of conspecifics but not of humans. However, because the subjects in the experiment were raised in a large social group and had considerably less exposure to humans than to…

Subordinate-level category-learning processes in infants were investigated with ERP and looking-time measures. ERPs were recorded while 6- to 7-month-olds were presented with Saint Bernard images during familiarization, followed by novel Saint Bernards interspersed with Beagles during test. In addition, infant looking times were measured during a…

We investigated whether great apes, like human infants, monkeys and dogs, are subject to a strong gravity bias when tested with the tubes task, and--in case of mastery--what the source of competence on the tubes task is. We presented 22 apes with three versions of the tubes task, in which an object is dropped down a tube connected to one of three…

Why are snakes such a common target of fear? One current view is that snake fear is one of several innate fears that emerge spontaneously. Another is that humans have an evolved predisposition to learn to fear snakes. In the first study reported here, 9- to 10-month-old infants showed no differential spontaneous reaction to films of snakes versus…

Animal studies demonstrate that maternal touch and contact regulate infant stress, and handling during periods of maternal deprivation attenuates the stress response. To measure the effects of touch on infant stress reactivity during simulated maternal deprivation, 53 dyads were tested in two paradigms: still-face (SF) and still-face with maternal…