Minors' consent to treatment: A developmental perspective.

Discusses the cognitive and behavioral characteristics of minors in relation to the question of competence to consent to treatment. The legal standard (knowing, intelligent, and voluntary) used to judge the effectiveness of consent is translated into psychological concepts, especially cognitive abilities. A review of developmental psychological research is presented, which examines these concepts as they relate to minors' abilities to satisfy the legal standard. It is suggested that cognitive developmental stages associated with ages below 11–23 yrs might exclude such minors from meaningful consent. In addition to cognitive considerations, certain results suggest that the tendency toward deference in early adolescence is so normative that capacity for voluntary consent is questionable through age 14, but existing evidence provides no psychological grounds for maintaining the general legal assumption that minors at age 15 and above cannot provide competent consent. (63 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

On the specificity of face cognition compared with general cognitive functioning across adult age.

Face cognition is considered a specific human ability, clearly differentiable from general cognitive functioning. Its specificity is primarily supported by cognitive-experimental and neuroimaging research, but recently also from an individual differences perspective. However, no comprehensive behavioral data are available, which would allow estimating lifespan changes of the covariance structure of face-cognition abilities and general cognitive functioning as well as age-differences in face cognition after accounting for interindividual variability in general cognition. The present study aimed to fill this gap. In an age-heterogeneous (18–82 years) sample of 448 adults, we found no factorial dedifferentiation between face cognition and general cognition. Age-related differences in face memory were still salient after taking into account changes in general cognitive functioning. Face cognition thus remains a specific human ability compared with general cognition, even until old age. We discuss implications for models of cognitive aging and suggest that it is necessary to include more explicitly special social abilities in those models. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Reflections of evolution and culture in children's cognition: Implications for mathematical development and instruction.

An evolution-based framework for understanding biological and cultural influences on children's cognitive and academic development is presented. The utility of this framework is illustrated within the mathematical domain and serves as a foundation for examining current approaches to educational reform in the United States. Within this framework, there are two general classes of cognitive ability, biologically primary and biologically secondary. Biologically primary cognitive abilities appear to have evolved largely by means of natural or sexual selection. Biologically secondary cognitive abilities reflect the co-optation of primary abilities for purposes other than the original evolution-based function and appear to develop only in specific cultural contexts. A distinction between these classes of ability has important implications for understanding children's cognitive development and achievement. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Differentiation of cognitive abilities across the life span.

Existing representations of cognitive ability structure are exclusively based on linear patterns of interrelations. However, a number of developmental and cognitive theories predict that abilities are differentially related across ages (age differentiation–dedifferentiation) and across levels of functioning (ability differentiation). Nonlinear factor analytic models were applied to multivariate cognitive ability data from 6,273 individuals, ages 4 to 101 years, who were selected to be nationally representative of the U.S. population. Results consistently supported ability differentiation but were less clear with respect to age differentiation–dedifferentiation. Little evidence for age modification of ability differentiation was found. These findings are particularly informative about the nature of individual differences in cognition and about the developmental course of cognitive ability level and structure. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Quantitative Genetic Analysis of Latent Growth Curve Models of Cognitive Abilities in Adulthood.

Though many cognitive abilities exhibit marked decline over the adult years, individual differences in rates of change have been observed. In the current study, biometrical latent growth models were used to examine sources of variability for ability level (intercept) and change (linear and quadratic effects) for verbal, fluid, memory, and perceptual speed abilities in the Swedish Adoption/Twin Study of Aging. Genetic influences were more important for ability level at age 65 and quadratic change than for linear slope at age 65. Expected variance components indicated decreasing genetic and increasing nonshared environmental variation over age. Exceptions included one verbal and two memory measures that showed increasing genetic and nonshared environmental variance. The present findings provide support for theories of the increasing influence of the environment with age on cognitive abilities. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Genetic variance in processing speed drives variation in aging of spatial and memory abilities.

Previous analyses have identified a genetic contribution to the correlation between declines with age in processing speed and higher cognitive abilities. The goal of the current analysis was to apply the biometric dual change score model to consider the possibility of temporal dynamics underlying the genetic covariance between aging trajectories for processing speed and cognitive abilities. Longitudinal twin data from the Swedish Adoption/Twin Study of Aging, including up to 5 measurement occasions covering a 16-year period, were available from 806 participants ranging in age from 50 to 88 years at the 1st measurement wave. Factors were generated to tap 4 cognitive domains: verbal ability, spatial ability, memory, and processing speed. Model-fitting indicated that genetic variance for processing speed was a leading indicator of variation in age changes for spatial and memory ability, providing additional support for processing speed theories of cognitive aging. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Age changes in processing speed as a leading indicator of cognitive aging.

Bivariate dual change score models were applied to longitudinal data from the Swedish Adoption/Twin Study of Aging to compare the dynamic predictions of 2-component theories of intelligence and the processing speed theory of cognitive aging. Data from up to 5 measurement occasions covering a 16-year period were available from 806 participants ranging in age from 50 to 88 years at the first measurement wave. Factors were generated to tap 4 general cognitive domains: verbal ability, spatial ability, memory, and processing speed. Model fitting indicated no dynamic relationship between verbal and spatial factors, providing no support for the hypothesis that age changes in fluid abilities drive age changes in crystallized abilities. The results suggest that, as predicted by the processing speed theory of cognitive aging, processing speed is a leading indicator of age changes in memory and spatial ability, but not verbal ability. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Continuity and change in general cognitive ability from 1 to 7 years of age.

Explored observed and latent sources of individual differences in cognitive development in data from adopted and nonadopted siblings measured from ages 12 mo to 7 yrs and identical and nonidentical twins measured from ages 12–36 mo. Longitudinal path models, designed to examine the structure of observed stability and assess the genetic and environmental sources of age-to-age change and continuity, suggest that observed continuity arises from age-specific effects that persist over time and from developmental influences that are static and unchanging. Genetic influences account for the age-specific yet persistent effects, shared sibling environment effects are constant from 1–7 yrs of age, and nonshared environmental factors are specific to each measurement age. Thus, genetic influences are a major source of both continuity and change in mental development, whereas shared and nonshared environment effects contribute to continuity and change, respectively. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Judgments about estrogen replacement therapy: The role of age, cognitive abilities, and beliefs.

This study investigated age, cognitive abilities, health beliefs, and other factors in women's judgments about effective treatments for menopause. Women (N?=?102) ranging in age from 20 to 79 read a vignette about a woman facing a decision about Estrogen Replacement Therapy (ERT) and then made judgments about what should be done. Participants also completed a battery of questions pertaining to ERT and cognitive abilities. Path-analytic techniques were used to determine the role of specific cognitive abilities and the representation of menopause and its treatment in making judgments about ERT treatments. Cognitive abilities had direct effects on treatment decisions. Education affected the number of perceived options for treatment. Age and education indirectly affected treatment decisions, operating through cognitive abilities. Factors related to the mental representation of menopause had no direct effects and few indirect effects on treatment decisions. Potential mechanisms that can help older adults compensate for declines in cognitive abilities in medical decisions are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The structure of language abilities at 4 years: A twin study.

Normal language development was studied in 310 pairs of 4-year-old twins born in the United Kingdom in 1994. Twins were assessed individually in their homes on a diverse battery of language and nonverbal measures. Rotated factor analyses indicated the presence of a general Language factor (L) as well as a general Nonverbal (NV) factor. Moderate genetic influence was found for both L and NV abilities. Bivariate genetic analysis estimated a genetic correlation of .63 between L and NV abilities, implying that over half of the genetic influence on L overlaps with genetic influence on NV. These results suggest that at age 4, genetic influences on individual differences in language overlap substantially with genetic influences on individual differences in other cognitive abilities, although perhaps less so than later in development. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Visual learning and memory as functions of age

Age-related changes have been reported for a range of perceptual and cognitive functions. We investigated visual acuity and vernier acuity, as well as visual memory and learning, in four age groups, each comprising 10 subjects and ranging from adolescence to an age group up to 66 years. The groups were matched on general abilities for visuospatial information processing. Visual acuity decreased slightly with increasing age. The reproduction of more complex geometrical material which exceeded short-term memory capacities was significantly impaired in the oldest group relative to young adults. However, vernier acuity thresholds and improvement of thresholds with training did not differ in the four groups. Short-term retention of visual stimuli across 1 or 4 sec was also comparable in the different age groups. Those visual abilities that are limited primarily by cortical, not retinal, factors remained relatively unchanged in our observers despite age-related changes in the eye. Visual memory functions which tap working and long-term memory abilities, on the other hand, showed a significant age-associated decline during adulthood.     

Age-sensitive cognitive abilities related to children's acquisition of spatial knowledge.

Two experiments were conducted to determine the extent to which developmental improvement in children's performance on tasks requiring the acquisition of spatial knowledge was related to age-sensitive cognitive abilities. The results of path analyses in Exp 1 indicated that the relationship between age and the acquisition of landmark knowledge was, in fact, mediated by recognition-in-context memory, whereas relationships between age and route knowledge and between age and landmark judgment were unmediated. Similar analyses in Exp 2 indicated that perceptual-motor speed mediated the relationships between age and route knowledge and between age and landmark knowledge. Again, the relationship between age and landmark judgment was unmediated. Overall, the results suggest that the approach used in these experiments can provide new insight into the relationship between spatial cognitive development as a specialized research area and cognitive development in general. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Global and domain-specific changes in cognition throughout adulthood.

Normative adult age-related decrements are well documented for many diverse forms of effortful cognitive processing. However, it is currently unclear whether each of these decrements reflects a distinct and independent developmental phenomenon, or, in part, a more global phenomenon. A number of studies have recently been published that show moderate to large magnitudes of positive relations among individual differences in rates of changes in different cognitive variables during adulthood. This suggests that a small number of common dimensions or even a single common dimension may underlie substantial proportions of individual differences in aging-related cognitive declines. This possibility was directly examined using data from 1,281 adults 18–95 years of age who were followed longitudinally over up to 7 years on 12 different measures of effortful processing. Multivariate growth curve models were applied to examine the dimensionality of individual differences in longitudinal changes. Results supported a hierarchical structure of aging-related changes, with an average of 39% of individual differences in change in a given variable attributable to global (domain-general) developmental processes, 33% attributable to domain-specific developmental processes (abstract reasoning, spatial visualization, episodic memory, and processing speed), and 28% attributable to test-specific developmental processes. Although it is often assumed that systematic and pervasive sources of cognitive decline only emerge in later adulthood, domain-general influences on change were apparent for younger (18–49 years), middle aged (50–69 years), and older (70–95 years) adults. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

On the locus and process of magnification of age differences during mnemonic training.

The focus of this study was on developmental reserve capacity in old age as revealed by testing-the-limits. Examined were (1) the time course of training-related magnification of age differences in serial word recall and (2) predictability of training gains by pretest individual differences in cognitive abilities. In 20 sessions, young (n?=?18) and old (n?=?19) adults were taught to recall lists of 30 words using the Method of Loci. Age differences were magnified early in practice at long presentation times (20 sec and 15 sec per word) and later at 5 sec per word. Regression of posttraining scores on various pretraining abilities revealed significant effects of digit symbol substitution. Also, consistent with the assumption of age-related decline in developmental reserve capacity, the unique variance in serial word recall associated with age group became more salient as the training unfolded. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Individual differences in rates of change in cognitive abilities of older persons.

The authors examined change in cognitive abilities in older Catholic clergy members. For up to 6 years, participants underwent annual clinical evaluations, which included a battery of tests from which summary measures of 7 abilities were derived. On average, decline occurred in each ability and was more rapid in older persons than in younger persons. However, wide individual differences were evident at all ages. Rate of change in a given domain was not strongly related to baseline level of function in that domain but was moderately associated with rates of change in other cognitive domains. The results suggest that change in cognitive function in old age primarily reflects person-specific factors rather than an inevitable developmental process. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The course of adult intellectual development.

A program of research is summarized that represents the author's lifelong efforts to understand the adult life course of intellectual abilities. The Seattle Longitudinal Study has assessed mental abilities in more than 5,000 adults and has followed some for as long as 35 yrs. Integrative findings are provided on patterns and magnitudes of age changes, cohort differences, factor structure of mental abilities, antecedents for individual differences in aging trajectories, and interventions designed to remediate cognitive aging efforts. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Psychosocial outcomes in later life: A multivariate model.

A conceptual model was developed to identify developmental self-regulatory pathways to optimal psychosocial outcomes in adulthood. The model delineates influences among age, possible selves, developmental processes (i.e., coping, control), and well-being. Results showed age effects on all constructs except selective control. Three consistently common predictors of well-being (i.e., goal pursuit, goal adjustment, and optimization) emerged. The effects of age on well-being were differentially mediated by developmental processes. Specifically, negative age-related changes in offensive processes (i.e., goal attainment) were offset by positive influences of defensive processes (i.e., goal adjustment), which had the net effect of preserving well-being. The model demonstrates a more optimistic pattern of aging in which gains offset losses leading to positive outcomes and highlights the importance of examining both independent and combined influences of age, self, and developmental processes on psychosocial outcomes. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The cognitive differentiation-integration effort hypothesis: A synthesis between the fitness indicator and life history models of human intelligence.

This article presents a potential synthesis between the fitness indicator and life history models of human intelligence through consideration of the phenomena of ability differentiation and integration. The cognitive differentiation-integration effort hypothesis proposes that these effects result from a life history tradeoff between cognitive integration effort, a mating effort component associated with strengthening the positive manifold amongst abilities; and cognitive differentiation effort, a somatic effort component associated with the cultivation of specific abilities. This represents one of two largely independent sources of genetic variance in intelligence; the other is mediated by general fitness and mutation load and is associated with individual differences in levels of 'genetic g'. These two sources (along with a common source of environmental variance) combine to give rise to a variety of cognitive phenotypes characterized by different combinations of high or low levels of 'genetic g' and cognitive specialism or generalism. Fundamental to this model is the assumption that measures of life history speed (K) and g are essentially independent, which is demonstrated via meta-analysis of 10 studies reporting correlations between the variables (ρ = .023, ns, n = 2056). The implications of the model are discussed in an evolutionary, ecological, and developmental context. Seven key predictions are made in the discussion which if tested could provide definitive evidence for the hypothesis. (PsycINFO Database Record (c) 2011 APA, all rights reserved)