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171.
New Caledonian crows make and use tools, and tool types vary over geographic landscapes. Social learning may explain the variation in tool design, but it is unknown to what degree social learning accounts for the maintenance of these designs. Indeed, little is known about the mechanisms these crows use to obtain information from others, despite the question’s importance in understanding whether tool behavior is transmitted via social, genetic, or environmental means. For social transmission to account for tool-type variation, copying must utilize a mechanism that is action specific (e.g., pushing left vs. right) as well as context specific (e.g., pushing a particular object vs. any object). To determine whether crows can copy a demonstrator’s actions as well as the contexts in which they occur, we conducted a diffusion experiment using a novel foraging task. We used a nontool task to eliminate any confounds introduced by individual differences in their prior tool experience. Two groups had demonstrators (trained in isolation on different options of a four-option task, including a two-action option) and one group did not. We found that crows socially learn about context: After observers see a demonstrator interact with the task, they are more likely to interact with the same parts of the task. In contrast, observers did not copy the demonstrator’s specific actions. Our results suggest it is unlikely that observing tool-making behavior transmits tool types. We suggest it is possible that tool types are transmitted when crows copy the physical form of the tools they encounter.  相似文献   
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Components of attention during infants' manipulative exploration   总被引:1,自引:1,他引:1  
H A Ruff 《Child development》1986,57(1):105-114
The purpose of the project was to investigate attention in infants as they manipulate objects. It was hypothesized that examining, in contrast to other activity, reflects focused attention and active intake of information. The first study with 7- and 12-month-olds supported the hypothesis; examining declined with increasing familiarity, while other behaviors, such as mouthing and banging, did not, and examining occurred before other behaviors temporally. The latency to examine declined significantly with age. The second and third studies investigated the effects of age and familiarity on both latency to and duration of examining. Latency again decreased with age but did not change with increasing familiarity. In contrast, duration of examining did not vary systematically with age but declined sharply with familiarity. In a fourth study, latency to examine and duration of examining were related to different measures of attention at 3 1/2 years. The combination of results suggests that the latency and duration measures reflect different aspects of attention--a short-term reaction to object novelty and a more sustained response to the object and its characteristics.  相似文献   
174.
H M Breland 《Child development》1974,45(4):1011-1019
Two samples of National Merit Scholarship participants test in 1962 and the entire population of almost 800,000 participants tested in 1965 were examined. Consistent effects in all 3 groups were observed with respect to both birth order and family size (1st born and those of smaller families scored higher). Control of both socioeconomic variables and maternal age, by analysis of variance as well as by analysis of covariance, failed to alter the relationships. Stepdown analyses suggested that the effects were due to a verbal component and that no differences were attributable to nonverbal factors. Mean test scores were computed for detailed sibship configurations based on birth order, family size, sibling spacing, and sibling sex.  相似文献   
175.
Given that gestures may provide access to transitions in cognitive development, preschoolers' performance on standard tasks was compared with their performance on a new gesture false belief task. Experiment 1 confirmed that children (N=45, M age=54 months) responded consistently on two gesture tasks and that there is dramatic improvement on both the gesture false belief task and a standard task from ages 3 to 5. In 2 subsequent experiments focusing on children in transition with respect to understanding false beliefs (Ns=34 and 70, M age=48 months), there was a significant advantage of gesture over standard and novel verbal-response tasks. Iconic gesture may facilitate reasoning about opaque mental states in children who are rapidly developing concepts of mind.  相似文献   
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178.
Cognitive deficits in reading disability and attention deficit disorder   总被引:12,自引:0,他引:12  
This paper presents data from three studies (a cross-sectional study of school-referred children, a test-retest study of subtypes of reading disabilities, and a study of a large, random sample of first graders) that focus on specifying the cognitive deficits associated with reading difficulties and separating them from those associated with attentional deficits. The cognitive deficits associated with difficulty in reading were consistent across samples, developmental levels, definitions, and subtypes of reading disabilities. With IQ, age, and sex controlled for, poor readers were significantly impaired on measures of naming and phonological awareness. The effects of attentional deficits were more variable and complex but were clearly separate from the reading disability effects.  相似文献   
179.
Forty-five abusive parents (40 mothers, 5 fathers) in treatment at a large, urban medical center's child abuse program were compared on 22 parent, child, and treatment variables posited to bear on reabuse. While no one variable by itself was strongly associated with reabuse, the data indicated that interactions involving several variables (e.g., income source, marital status, and the abuser's personal abuse history) significantly differentiated between reabusers and nonreabusers. Implications of the findings for research and clinical intervention are discussed.  相似文献   
180.
School‐wide positive behavior support (SWPBS) is a systemic approach for implementing a proactive schoolwide discipline and for improving students’ academic and behavioral outcomes by targeting the school’s organizational and social culture. With a multilevel approach, the present study evaluates the relative effectiveness of SWPBS on teachers’ perceptions of the student behavior (N = 3,295) across schools, teachers, and children using a multilevel approach. We assessed teacher perception of student problem behavior five times during a 3‐year implementation of SWPBS in 23 Dutch schools. Multilevel analyses not only revealed a small increase in perceived prosocial behavior and a small decrease in problems with peers, but also different effects across children, teachers, and schools. Effects were stronger for girls and for students with higher severity of perceived problems at baseline. At teachers’ level, higher mean baseline severity of perceived problems was associated with the reduced impact of SWPBS on perceived emotional problems and problems with peers. At the school level, effects were stronger for regular schools as compared with special needs schools.  相似文献   
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