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The developmental origins of sharing remain little understood. Using procedures adapted from research on prosocial behavior in chimpanzees, we presented 18- and 25-month-old children with a sharing task in which they could choose to deliver food to themselves only, or to both themselves and another person, thereby making it possible for them to share(More)
The study explored how the meaning of prosocial behavior changes over toddlerhood. Sixty-five 18- and 30-month-olds could help an adult in 3 contexts: instrumental (action based), empathic (emotion based), and altruistic (costly). Children at both ages helped readily in instrumental tasks. For 18-month-olds, empathic helping was significantly more difficult(More)
To examine early developments in other-oriented resource sharing, fifty-one 18- and 24-month-old children were administered 6 tasks with toys or food that could be shared with an adult playmate who had none. On each task the playmate communicated her desire for the items in a series of progressively more explicit cues. Twenty-four-month-olds shared(More)
BACKGROUND Youth and adults with psychopathic traits display disrupted reinforcement learning. Advances in measurement now enable examination of this association in preschoolers. The current study examines relations between reinforcement learning in preschoolers and parent ratings of reduced responsiveness to socialization, conceptualized as a developmental(More)
Does the chimpanzee attribute goals to others? Recent infant studies using the looking time measure have been interpreted as evidence that human infants attribute goals. An experiment modeled on these studies was carried out on chimpanzees, and the chimpanzees responded the way infants do. This indicates that chimpanzees also attribute goals and hence that(More)
The second year of life marks the beginning of empathic responsiveness to others' distress, a hallmark of human interaction. We examined the role of social understanding (self-other understanding and emotion understanding) and empathic disposition in individual differences in 12- to 24-month olds' responses to mothers' and an unfamiliar infant peer's(More)
What role does socialization play in the origins of prosocial behavior? We examined one potential socialization mechanism, parents' discourse about others' emotions with very young children in whom prosocial behavior is still nascent. Two studies are reported, one of sharing in 18- and 24-month-olds (n = 29), and one of instrumental and empathy-based(More)
BACKGROUND Asthma can be difficult to diagnose, but bronchial provocation with methacholine, exercise or mannitol is helpful when used to identify bronchial hyperresponsiveness (BHR), a key feature of the disease. The utility of these tests in subjects with signs and symptoms of asthma but without a clear diagnosis has not been investigated. We investigated(More)
Previous research suggests that community violence impacts mental health outcomes, but much of this research has not (a) distinguished between different types of community violence, (b) examined gender differences, and (c) focused on youth living in urban poverty. The current study addresses these questions. Participants were 306 youth (23 % girls) and one(More)
This study explored children's use of external representations. Experiment 1 focused on representations of self: Self-recognition was assessed by a mark test as a function of age (3 vs. 4 years), delay (5 s vs. 3 min), and media (photographs vs. drawings). Four-year-olds outperformed 3-year-olds; children performed better with photographs than drawings; and(More)