As adults, we know that others' mental states, such as beliefs, guide their behavior and that these mental states can deviate from reality. Researchers have examined whether young children possess adult-like theory of mind by focusing on their understanding about others' false beliefs. The present research revealed that 10-month-old infants seemed…

Previous research suggests that perspective-taking and other "theory of mind" processes may be cognitively demanding for adult participants, and may be disrupted by concurrent performance of a secondary task. In the current study, a Level-1 visual perspective task was administered to 32 adults using a dual-task paradigm in which the secondary task…

There is currently much controversy about which, if any, mental states chimpanzees and other nonhuman primates understand. In the current two studies we tested both chimpanzees' and human children's understanding of both knowledge-ignorance and false belief--in the same experimental paradigm involving competition with a conspecific. We found that…

The term synaesthesia has been applied to a range of different sensory-perceptual and cognitive experiences, yet how these experiences are related to each other is not well understood. Not only are there disparate types of synaesthesia, but even within types there are vast individual differences in the way that stimuli induce synaesthesia and in…

Intersensory redundancy can facilitate animal and human behavior in areas as diverse as rhythm discrimination, signal detection, orienting responses, maternal call learning, and associative learning. In the realm of numerical development, infants show similar sensitivity to numerical differences in both the visual and auditory modalities. Using a…

Conflicting evidence has arisen from correlational studies regarding the role of executive control functions in Theory of Mind. The current study used dual-task manipulations of executive functions (inhibition, updating and switching) to investigate the role of these control functions in mental state and non-mental state tasks. The "Eyes"…

We hypothesized that women with Turner syndrome (45,X) with a single X-chromosome inherited from their mother may show mentalizing deficits compared to women of normal karyotype with two X-chromosomes (46,X). Simple geometrical animation events (two triangles moving with apparent intention in relation to each other) which usually elicit…

Infants know that humans are exempt from some of the principles that govern the motion of inanimate objects: for instance, humans can be caused to move without being struck. In the current study, we report that infants nevertheless do apply some of the same principles to both humans and objects, where appropriate. Five-month-old infants expect…

Recent work suggests that infants rely on mechanisms of object-based attention and short-term memory to represent small numbers of objects. Such work shows that infants discriminate arrays containing 1, 2, or 3 objects, but fail with arrays greater than 3 [Feigenson, L., & Carey, S. (2003). Tracking individuals via object-files: Evidence from…

The present research investigated whether 13.5-month-old infants would attribute to an actor a disposition to perform a recurring action, and would then use this information to predict which of two new objects--one that could be used to perform the action and one that could not--the actor would grasp next. During familiarization, the infants…

Developmental research suggests that some of the mechanisms that underlie numerical cognition are present and functional in human infancy. To investigate these mechanisms and their developmental course, psychologists have turned to behavioral and electrophysiological methods using briefly presented displays. These methods, however, depend on the…

Infants' abilities to identify objects based on their perceptual features develop gradually during the first year and possibly beyond. Earlier we reported [Kaldy, Z., & Leslie, A. M. (2003). Identification of objects in 9-month-old infants: Integrating "what" and "where" information. Developmental Science, 6, 360-373] that infants at 9 months of…

Sex differences in cognitive skills, grouped into motor, spatial and linguistic areas, are assessed in relation to current theories of cerebral lateralization. Few convincing sex differences exist, either overall, or in interactions with functional localization. Qualifying criteria include age, birth order, culture, sex of experimenter and sex…

Examined whether 2-year-olds can learn a novel part name of an unfamiliar object when adult demonstrates action upon object. Asked 24 Japanese 2-year-olds to choose referent for a whole object and part of the object in forced choice tests. Found that young children are able to override whole object assumption when actions of parts of objects are…