In learning mathematics, children must master fundamental logical relationships, including the inverse relationship between addition and subtraction. At the start of elementary school, children lack generalized understanding of this relationship in the context of exact arithmetic problems: they fail to judge, for example, that 12 + 9 - 9 yields…

Traditional theories of moral development emphasize the role of controlled cognition in mature moral judgment, while a more recent trend emphasizes intuitive and emotional processes. Here we test a dual-process theory synthesizing these perspectives. More specifically, our theory associates utilitarian moral judgment (approving of harmful actions…

A basic problem of daily life is determining who owns what. One way that people may solve this problem is by relying on a "first possession" heuristic, according to which the first person who possesses an object is its owner, even if others subsequently possess the object. We investigated preschoolers' use of this heuristic in five experiments. In…

The seeking of discontinuity in enumeration was recently renewed because Cowan [Cowan, N. (2001). "The magical number 4 in short-term memory: A reconsideration of mental storage capacity." "Behavioral and Brain Sciences," 24, 87-185; Cowan, N. (2005). "Working memory capacity." Hove: Psychology Press] suggested that it allows evaluating the limit…

Evolutionary psychologists have proposed that humans possess cognitive mechanisms for social exchange, but have perhaps focused overmuch on "cheating", because avoiding exploitation in reciprocal exchange could be accomplished either by avoidance of defectors or by attraction to cooperators. Past studies that have claimed to support the existence…

Human infants readily interpret the actions of others in terms of goals, but the origins of this important cognitive skill are keenly debated. We tested whether infants recognize others' actions as goal-directed on the basis of their experience with carrying out and observing goal-directed actions, or whether their perception of a goal-directed…

Adaptation to right-shifting prisms improves left neglect for mental number line bisection. This study examined whether adaptation affects the mental number line in normal participants. Thirty-six participants completed a mental number line task before and after adaptation to either: left-shifting prisms, right-shifting prisms or control…

Speakers are faster and more accurate at processing certain sound sequences within their language. Does this reflect the fact that these sequences are frequent or that they are phonetically less complex (e.g., easier to articulate)? It has been difficult to contrast these two factors given their high correlation in natural languages. In this…

Three experiments addressed the hypothesis that production factors constrain phonotactic learning in adult English speakers, and that this constraint gives rise to a markedness effect on learning. In Experiment 1, an acoustic measure was used to assess consonant-consonant coarticulation in naturally produced nonwords, which were then used as…

Prior eye-tracking studies of spoken sentence comprehension have found that the presence of two potential referents, e.g., two frogs, can guide listeners toward a Modifier interpretation of "Put the frog on the napkin..." despite strong lexical biases associated with "Put" that support a Goal interpretation of the temporary ambiguity (Tanenhaus,…

An influential series of studies have argued that young children are unable to use landmark information to reorient. However, these studies have used artificial experimental environments that may lead to an underestimation of the children's ability. We tested whether young children could reorient using landmarks in an ecologically valid setting.…

English and Italian children with dyslexia were compared with children with reading difficulties associated with low-IQ on tests of simple and choice RT, and in number and symbol scanning tasks. On all four speed-of-processing tasks, children with low-IQ responded more slowly than children with dyslexia and age-controls. In the choice RT task, the…

Preschoolers use information from interventions, namely intentional actions, to make causal inferences. We asked whether children consider some interventions to be more informative than others based on two components of an actor's knowledge state: whether an actor "possesses" causal knowledge, and whether an actor is allowed to "use" their…

A considerable amount of research has uncovered heuristics that the visual system employs to keep track of objects through periods of occlusion. Relatively little work, by comparison, has investigated the online resources that support this processing. We explored how attention is distributed when featurally identical objects become occluded during…

Sixty-five children with specific reading disability (SRD), 25 children with specific language impairment (SLI), and 37 age-matched controls were tested for their frequency discrimination, rapid auditory processing, vowel discrimination, and consonant-vowel discrimination. Subgroups of children with SRD or SLI produced abnormal frequency…