David F. Bjorklund

The resources construct in cognitive development: Diverse sources of evidence and a theory of inefficient inhibition

Abstract The status of the generic resources hypothesis in developmental psychology is reviewed, including developmental data suggesting that limited mental resources is a causative factor in many developmental phenomena. Contemporary contributions from connectionist models and neuropsychology are presented and discussed as they pertain to the resources construct. The correlations between myelinization and the development of cognitive processing are discussed as possible explanations of developmental increases in functional short-term memory capacity. Finally, a model of inefficient inhibition in working memory is proposed. We propose that, with development, changes in childrens neurological systems lead to increased efficiency of inhibitory processing, contributing to increases in selective attention and ability to keep task-irrelevant information out of working memory. The model may provide a middle ground for both resource and nonresource theorists.

How age changes in knowledge base contribute to the development of children's memory: An interpretive review

Abstract The influence of differences in knowledge base on childrens memory performance is reviewed. It is proposed that age differences in semantic memory affect the ease with which information in permanent memory can be activated, which in turn influences the amount of mental effort available for other cognitive operations. Having detailed knowledge about a set of items can influence memory performance by (a) increasing the accessibility of specific items (item-specific effects), (b) the relatively effortless activation of relations among sets of items (nonstrategic organization), or (c) facilitating the use of deliberate memory strategies. Concerning the latter, children are not expected to use sophisticated mnemonics until processing of individual items requires sufficiently little mental effort. As items and relations among items in childrens semantic memories become more elaboratively represented and easily activated, processing efficiency increases and deliberate strategies are more apt to be used.

Evolutionary Developmental Psychology.

The field of evolutionary developmental psychology can potentially broaden the horizons of mainstream evolutionary psychology by combining the principles of Darwinian evolution by natural selection with the study of human development, focusing on the epigenetic effects that occur between humans and their environment in a way that attempts to explain how evolved psychological mechanisms become expressed in the phenotypes of adults. An evolutionary developmental perspective includes an appreciation of comparative research and we, among others, argue that contrasting the cognition of humans with that of nonhuman primates can provide a framework with which to understand how human cognitive abilities and intelligence evolved. Furthermore, we argue that several <<immature>> aspects of childhood (e.g., play and immature cognition) serve both as deferred adaptations as well as imparting immediate benefits. Intense selection pressure was surely exerted on childhood over human evolutionary history and, as a result, neglecting to consider the early developmental period of children when studying their later adulthood produces an incomplete picture of the evolved adaptations expressed through human behavior and cognition.

Child Development and Evolutionary Psychology

Evolutionary developmental psychology involves the expression of evolved, epigenetic programs, as described by the developmental systems approach, over the course of ontogeny. There have been different selection pressures on organisms at different times in ontogeny, and some characteristics of infants and children were selected in evolution to serve an adaptive function at that time in their life history rather than to prepare individuals for later adulthood. Examples of such adaptive functions of immaturity are provided from infancy, play, and cognitive development. Most evolved psychological mechanisms are proposed to be domain specific in nature and have been identified for various aspects of childrens cognitive and social development, most notably for the acquisition of language and for theory of mind. Differences in the quality and quantity of parental investment affect childrens development and influence their subsequent reproductive and childcare strategies. Some sex differences observed in childhood, particularly as expressed during play, are seen as antecedents and preparations for adult sex differences. Because evolved mechanisms were adaptive to ancestral environments, they are not always adaptive for contemporary people, and this mismatch of evolved mechanisms with modern environments is seen in childrens maladjustment to some aspects of formal schooling. We argue that an evolutionary perspective can be valuable for developing a better understanding of human ontogeny in contemporary society and that a developmental perspective is important for a better understanding of evolutionary psychology.

The adaptive nature of cognitive immaturity.

The prolonged cognitive immaturity characteristic of human youth is described as adaptive in and of itself. The adaptive nature of cognitive immaturity is examined in developmental research in the areas of metacognition, egocentricity, plasticity and the speed of information processing, and language acquisition. Some of the consequences of viewing childrens immature cognition as adaptive for cognitive development and education are discussed.

The Ontogeny of Inhibition Mechanisms: A Renewed Approach to Cognitive Development

A major focus of developmental researchers has concerned the isolation of the mechanisms behind age-related improvements in cognition. Working memory capacity, metacognitive abilities, strategies, and knowledge base have all been touted as important causative agents in children’s thinking (e.g., Bjorklund, 1990; Schneider & Pressley, 1989). Meanwhile, although inhibition processes enjoyed a role in early theories of cognition and development (Luria, 1961; Underwood, 1957), inhibition has been neglected, in part, because it has not appeared to be compatible with the computer metaphor of cognition (Bjork, 1989; Dempster, this volume). Currently, the developmental significance of inhibitory processing is garnering renewed support from such diverse areas as memory development (Bjorklund & Harnishfeger, 1990), object permanence in infancy (Diamond, 1988), and discourse processing in the aged (Hasher & Zacks, 1989). It is time to reexamine inhibition as a central mechanism in accounts of cognitive development.

The Role of Conceptual Knowledge in the Development of Organization in Children’s Memory

The development of organization in children’s memory has received substantial research attention over the past 10 years (for reviews see Lange, 1978; Mandler, 1979; Moely, 1977; Ornstein & Corsale, 1979). Organization is customarily defined as the structure discovered or imposed upon a set of items by a learner, with this structure facilitating retrieval of items from memory (see Chapter 1 by Ackerman for a discussion of factors affecting retrieval from children’s memory). Organization has generally been thought of as a strategic process (i.e., deliberate and effortful), with age changes in the use of organization being attributed to age differences in strategic functioning. Such a conclusion is supported by the results of numerous studies demonstrating that young children, who show little evidence of spontaneous organization, can be trained to cluster their recall according to adult categorizations (e.g., Bjorklund, Ornstein, & Haig, 1977; Moely & Jeffrey, 1974; Moely, Olson, Halwes, & Flavell, 1969). In this chapter, I dispute this position, arguing instead that most of the age changes in the organization of children’s recall are not strategic, but rather can be attributed to developmental changes in the structure and content of children’s conceptual representations. Organization in memory does become strategic, I believe, sometime during adolescence, resulting in a qualitatively different type of memory functioning. However, I argue that the regular improvements observed in memory organization over the course of the preschool and elementary school years can most parsimoniously be attributed to developmental differences in the structure of semantic memory and the ease with which certain types of semantic relationships can be activated.

The evolution of inhibition mechanisms and their role in human cognition and behavior

Publisher Summary This chapter provides an account of the evolution of human cognitive and behavioral inhibition mechanisms. To anticipate, it is proposed that in hominid phylogeny pressures related to intraspecific cooperation and competition led to enlargement of the neocortex, including connections between the prefrontal lobe and the limbic system. These connections afforded greater voluntary inhibitory control over sexual and aggressive behaviors, which in turn led to improved social harmony. As inhibition mechanisms came increasingly under cortical control, neural circuits, initially evolved to inhibit emotional responding, were recruited for purposes of inhibiting other social behaviors and cognitions, contributing to the current cognitive system. This chapter begins with a review on the role of inhibition in contemporary human cognition and behavior, its development, and the neural basis for such inhibition.

A developmental perspective on individual differences in inhibition

Abstract Our thesis is that differences in the efficiency of inhibition and interference sensitivity contribute to individual differences in cognitive processing. We argue that inhibition models from the developmental literature may also be applied to the study of individual differences. We review evidence from a variety of psychological literatures that suggests that inhibitory efficiency varies among people. This review examines inhibition in individuals differing in frontal-lobe functioning, including individuals with attention-deficit disorder, conduct disorder, psychopathology, obsessive-compulsive disorder, and schizophrenia; and inhibition in individuals differing in cognitive skills or abilities, including individuals with mental retardation, reading and learning disabilities, giftedness and creativity, various cognitive styles, and interference sensitivity in everyday life. Following our review, we discuss the role of inhibition in models of cognitive development, and how inhibitory efficiency might be related to working memory capacity, strategy use, and knowledge. Finally, we speculate on the underlying causes of inhibitory processes, the cognitive benefits of inefficient inhibition, and inhibition as a stable component of intelligence.

Developmental Patterns of Eyewitness Memory and Suggestibility

Adults, 8-, and 6-year-olds viewed a video of 2 children arguing over a bicycle and were asked free-and cured-recall as well as positive- and negative-leading questions in multiple interviews. Correct free recall varied with the type of the item. Age differences were found for correct free recall, but not for unbiased cued recall. Unbiased cues evoked more correct and incorrect responses from all subjects. Incorrect free recall was at near floor levels. Forgetting for all ages was comparable when based on levels of initial free recall but was greater for the children when based on what was remembered to unbiased cued-recall questions. Age differences were found for suggestibility, with the 6-year-olds being more suggestible to the negative-leading questions than participants in the other two age groups. Adults demonstrated a rejection bias. Adults compared to children correctly recalled more peripheral items. Changed answers were most common for 6-year olds. Results and implications are discussed in terms of experiences an eyewitness could expect when involved in the pretrial testimony-taking events in a characteristic misdemeanor matter.Adults, 8-, and 6-year-olds viewed a video of 2 children arguing over a bicycle and were asked free-and cured-recall as well as positive- and negative-leading questions in multiple interviews. Correct free recall varied with the type of the item. Age differences were found for correct free recall, but not for unbiased cued recall. Unbiased cues evoked more correct and incorrect responses from all subjects. Incorrect free recall was at near floor levels. Forgetting for all ages was comparable when based on levels of initial free recall but was greater for the children when based on what was remembered to unbiased cued-recall questions. Age differences were found for suggestibility, with the 6-year-olds being more suggestible to the negative-leading questions than participants in the other two age groups. Adults demonstrated a rejection bias. Adults compared to children correctly recalled more peripheral items. Changed answers were most common for 6-year olds. Results and implications are discussed in terms of experiences an eyewitness could expect when involved in the pretrial testimony-taking events in a characteristic misdemeanor matter.