Never getting to zero: Elementary school students' understanding of the infinite divisibility of number and matter

Clinical interviews administered to third- to sixth-graders explored children's conceptualizations of rational number and of certain extensive physical quantities. We found within child consistency in reasoning about diverse aspects of rational number. Children's spontaneous acknowledgement of the existence of numbers between 0 and 1 was strongly related to their induction that numbers are infinitely divisible in the sense that they can be repeatedly divided without ever getting to zero. Their conceptualizing number as infinitely divisible was strongly related to their having a model of fraction notation based on division and to their successful judgment of the relative magnitudes of fractions and decimals. In addition, their understanding number as infinitely divisible was strongly related to their understanding physical quantities as infinitely divisible. These results support a conceptual change account of knowledge acquisition, involving two-way mappings between the domains of number and physical quantity.     

The role of phonological activation in the visual semantic retrieval of Chinese characters

The Stroop paradigm was used to examine the role of phonological activation in semantic access and its development in reading Chinese characters. Subjects (age 7-23 years) of different reading ability were asked to name the display color of Chinese characters. The characters were displayed in four different colors: red, yellow, blue and green. There were five types of relationships between a character and its display color: semantically congruent, phonologically congruent, semantically incongruent, phonologically incongruent and neutral. In addition to the classical Stroop effects, interference and facilitation effects from the homophones of color characters were also observed. The younger children and those with lower reading ability exhibited stronger Stroop effects. These findings suggest that phonological codes are activated automatically in Chinese character recognition. Furthermore, there is more phonological activation in the semantic retrieval of children in lower grades and those with lower reading ability.     

Intellectual Safety, Moral Atmosphere, and Epistemology in College Classrooms

Students report feeling safe to express and challenge their beliefs and assumptions in some classrooms and interactions but not in others. This paper proposes a definition of intellectual safety derived from student responses to their experience of safety or threat in college classrooms, and explores students' experience of intellectual safety in relation to epistemological development. Intellectual safety defined here has two components: epistemic fit or lack of fit between student and professor's epistemology, and moral climate. Students can be challenged in their world-views and feel either threatened, unsafe, and uncomfortable, or supported and safe despite possible discomfort. Experiencing an intellectually safe moral climate may create conditions and opportunities for epistemological reflection and change. Using concepts from moral theory, including moral type and moral perspectives of justice and care, I describe features of an intellectually safe moral climate during the cognitively and emotionally difficult time of epistemological development.     

The Role of Cognitive Deficits in the Development of Eating Disorders

Eating disorders (ED), including anorexia and bulimia nervosa, are chronic illnesses with periods of symptom exacerbation and remission. Because symptoms are usually present from 6 to 24 months before a diagnosis is made, aetiological agents are believed to be active well before symptoms appear. It is proposed that neuropsychological deficits in various cognitive domains preexist and underlie the aetiology of ED. This paper provides a comprehensive review of the literature relevant to neuropsychological deficits in ED patients and explores the relationship between cognitive deficits, psychosocial development, and the development of ED. Although the role of neuropsychological deficits in the evolution of ED requires further research, the proposed association has significant implications for clinical practice.     

Winnicott, Balint, and the Independent Tradition

This article compares and contrasts two main aspects of the work of Winnicott and Balint: their theories of infantile development and their theoretical and clinical work on the use of regression as a therapeutic agent. The relationship of their thinking to aspects of the British Independent Group's theories and clinical work is noted vis-à-vis the basic acceptance of classical theory and technique, acknowledgment and use of some of Klein's contributions, the influence of trauma and the external environment on psychic development and psychopathology, the importance of holding and the setting, and the reintegration of previously split off and lost parts of the self.     

Acquiring an understanding of design: evidence from children's insight problem solving

The human ability to make tools and use them to solve problems may not be zoologically unique, but it is certainly extraordinary. Yet little is known about the conceptual machinery that makes humans so competent at making and using tools. Do adults and children have concepts specialized for understanding human-made artifacts? If so, are these concepts deployed in attempts to solve novel problems? Here we present new data, derived from problem-solving experiments, which support the following. (i) The structure of the child's concept of artifact function changes profoundly between ages 5 and 7. At age 5, the child's conceptual machinery defines the function of an artifact as any goal a user might have; by age 7, its function is defined by the artifact's typical or intended use. (ii) This conceptual shift has a striking effect on problem-solving performance, i.e. the child's concept of artifact function appears to be deployed in problem solving. (iii) This effect on problem solving is not caused by differences in the amount of knowledge that children have about the typical use of a particular tool; it is mediated by the structure of the child's artifact concept (which organizes and deploys the child's knowledge). In two studies, children between 5 and 7 years of age were matched for their knowledge of what a particular artifact "is for", and then given a problem that can only be solved if that tool is used for an atypical purpose. All children performed well in a baseline condition. But when they were primed by a demonstration of the artifact's typical function, 5-year-old children solved the problem much faster than 6-7-year-old children. Because all children knew what the tools were for, differences in knowledge alone cannot explain the results. We argue that the older children were slower to solve the problem when the typical function was primed because (i) their artifact concept plays a role in problem solving, and (ii) intended purpose is central to their concept of artifact function, but not to that of the younger children.     

Career Centered High School Education and Post–High School Career Adaptation

This study examines the quality of the transition into employment roles among a socioeconomically diverse cohort of 1,143 high school seniors who were interviewed as seniors in 1998 and 2 years later. Focusing on both subjective and objective dimensions of work adaptation, analyses examine differences in these outcomes associated with taking a high school career-major versus a more traditional academic program. This type of major is intended to assist in the career development and economic adaptation of more disadvantaged young adults and follows from an ecological model emphasizing the importance of connections between educational and employment institutions in the socialization of young people. Results indicate small but significant effects of having the career-major for the perceptual variables. Group differences were not found for the variables assessing more objective qualities of their jobs. The discrepancy between subjective and objective outcomes may suggest a short-term psychological optimism in the absence of an objective situation that would justify this view. Discussion centers on the need for stronger institutional support for school-work connections.     

IQ stability: the relation between child and young adult intelligence test scores in low-birthweight samples

The stability of IQ from childhood to adulthood in low-birthweight subjects was measured in two independent samples with follow-up intervals of approximately 14 and 9.5 years. In both samples, intelligence was assessed with the WISC at a mean age of 9.5. Twenty-six subjects were retested with the WAIS at a mean age of 23.5, and 78 subjects with the BPP (the Danish Military Draft Board Intelligence Test) at the age of 19.1. Both samples obtained childhood and adult test scores below the expected means. For the Wechsler Verbal, Performance and Full-Scale IQs, the stability quotients were 0.86, 0.86, and 0.89 in the WAIS sample, and the retest correlations for the three IQs with the BPP score were 0.66, 0.65, and 0.74. Thus, the majority of children showed stable patterns of intellectual development from middle childhood to young adulthood.     

Behavioural development in a matching-to-sample task and token use by an infant chimpanzee reared by his mother

We investigated the behavioural and cognitive development of a captive male infant chimpanzee, Ayumu, raised by his mother, Ai. Here we report Ayumu's achievements up to the age of 2 years and 3 months, in the context of complex computer-controlled tasks. From soon after birth, Ayumu had been present during an experiment performed by his mother. The task consisted of two phases, a matching-to-sample task in which she received token rewards, and the insertion of these tokens into a vending machine to obtain food rewards. Ayumu himself received no reward or encouragement from humans for any of the actions he exhibited during the experiment. At the age of 9 months and 3 weeks, Ayumu performed his first matching-to-sample trial. At around 1 year and 3 months, he began to perform them consistently. Also during this period, he frequently stole food rewards from his mother. At 2 years and 3 months, Ayumu succeeded for the first time in inserting a token into the vending machine. Once he had succeeded in using a token, he performed both phases of the task in sequence 20 times consecutively. The infant's behaviour was not shaped by food rewards but by a strong motivation to copy his mother's behaviour. Our observations of Ayumu thus mirror the learning processes shown by wild chimpanzees.