Individual Differences In Age Research Articles

Inhibitory Control in Children with Autism Spectrum Disorder

Impairments in executive abilities such as cognitive flexibility have been identified in individuals with autism spectrum disorder (ASD). It remains unclear, however, whether such individuals also experience impairments in another executive ability: inhibitory control. In the present study, we administered three inhibitory tasks to 18 children with ASD, 23 siblings of children with ASD, and 25 typically developing children. After controlling for individual differences in age, overall IQ, and processing speed, children with ASD demonstrated impaired performance on two of the three inhibitory tasks. Results suggest that children with ASD experience circumscribed deficits in some but not all aspects of inhibitory control. More generally, the findings underscore the importance of using multiple measures to assess a putative single cognitive ability.

The relationship between visuo-spatial attention and nonword reading in developmental dyslexia

Focused visuo-spatial attention was studied in 10 developmental dyslexic children with impaired nonword reading, 10 dyslexic children with intact nonword reading, and 12 normally reading children. Reaction times to lateralized visual stimuli in a cued detection task showed that attentional facilitation of the target at the cued location was symmetrical in the three groups. However, dyslexics with impaired nonword reading selectively showed a lack of attentional inhibition for targets at the uncued location in the right visual field. This result was replicated in a second group of 13 dyslexics with impaired nonword reading. Individual differences in the ability of right attentional inhibition across the entire sample of dyslexics accounted for 17% of unique variance in nonword reading accuracy after controlling for individual differences in age, IQ, and phonological skills. A possible explanation based on the role of spatial attention mechanisms in the graphemic parsing process is discussed. Our results suggest that focused visuo-spatial attention may be crucial for nonword decoding.

Age, rank, and personality effects on the cortisol sedation stress response in young chimpanzees

Primates and other mammals exhibit a glucocorticoid response to somatic and psychosocial stressors. The pattern and degree of response varies both within and between species, but the factors affecting within-species variability have rarely been considered. Here we describe the 90-min serum cortisol response of 14 juvenile and adolescent chimpanzees to the stress of sedation with ketamine hydrochloride. We show age differences in both baseline cortisol and time of peak cortisol, with younger individuals (ages 4–5 years) showing higher baseline levels and an earlier peak response than older individuals (ages 8–9 years). However, we found no sex or rank-related differences in any of the sedation measures: baseline cortisol, cortisol peak time, peak cortisol level, or cortisol change from baseline. We also examined the relationship between these sedation stress measures and behavioral style score, and found that individuals scoring high in the “mellow” behavioral style component showed a greater stress response than individuals scoring lower in this component. Future studies should consider the role of individual differences in age and personality in the cortisol response to stress.

Individual differences in age and self-efficacy in the unemployed

The purpose of the present study was to investigate the role of age in influencing the relationships among general self-efficacy, proactive attitude, and proactive coping in unemployed people. The sample consisted of 55 male and 49 female unemployed Australians participating in Job Search Training courses. They completed the General Self-Efficacy (GSE) Scale, the Proactive Attitude (PA) Scale, and the Proactive Coping (PC) Scale. The GSE, PA, and PC scores were found to be correlated, and a moderating effect for age was found on the relationship between PA and GSE. Regression analysis indicated that the moderation process could be explained by a mediating effect of PC. The results are discussed in terms of social learning theory, and implications are drawn regarding customisation of training programs for the unemployed.

Conservation Behavior Is Here to Stay

Conservation Behavior Is Here to Stay

Implicit Learning in Children and Adults With Williams Syndrome

In comparison to explicit learning, implicit learning is hypothesized to be a phylogenetically older form of learning that is important in early developmental processes (e.g., natural language acquisition, socialization) and relatively impervious to individual differences in age and IQ. We examined implicit learning in a group of children and adults (9-49 years of age) with Williams syndrome (WS) and in a comparison group of typically developing individuals matched for chronological age. Participants were tested in an artificial-grammar learning paradigm and in a rotor-pursuit task. For both groups, implicit learning was largely independent of age. Both groups showed evidence of implicit learning but the comparison group outperformed the WS group on both tasks. Performance advantages for the comparison group were no longer significant when group differences in working memory or nonverbal intelligence were held constant.

Amplitude envelope onsets and developmental dyslexia: A new hypothesis.

A core difficulty in developmental dyslexia is the accurate specification and neural representation of speech. We argue that a likely perceptual cause of this difficulty is a deficit in the perceptual experience of rhythmic timing. Speech rhythm is one of the earliest cues used by infants to discriminate syllables and is determined principally by the acoustic structure of amplitude modulation at relatively low rates in the signal. We show significant differences between dyslexic and normally reading children, and between young early readers and normal developers, in amplitude envelope onset detection. We further show that individual differences in sensitivity to the shape of amplitude modulation account for 25% of the variance in reading and spelling acquisition even after controlling for individual differences in age, nonverbal IQ, and vocabulary. A possible causal explanation dependent on perceptual-center detection and the onset-rime representation of syllables is discussed.

Using Life-Span Models in Industrial-Organizational Psychology: The Theory of Selective Optimization With Compensation

Life-span models and their emphasis on individual differences in aging and development fit perfectly with industrial-organizational (I-O) psychology's underlying theoretical assumptions. Furthermore, certain life-span metatheories can provide an overarching framework from which to understand various I-O research areas. This article attempts to demonstrate how a specific life-span model of successful aging-selective optimization with compensation (SOC)-can be used as a metatheory for 3 specific areas of I-O psychology: work-family conflict, leadership, and organization-level functioning. Finally, methodological issues that researchers should consider when using the SOC model in the I-O arena are also discussed.

Sleep Patterns, Shiftwork, and Individual Differences: A Comparison of Onshore and Offshore Control-room Operators

The sleep patterns of offshore control-room operators were compared with those of personnel carrying out similar work onshore, taking into account individual differences in age, number of years of shiftwork, and neuroticism. The dependent variables were self-reported sleep quality and duration for day-shift (D-S) and night-shift (N-S) work, and during leave periods (L-P). Offshore workers reported longer N-S sleep duration, and lower D-S sleep quality than those onshore, but the two groups did not differ in L-P measures. The effects of environmental differences (onshore versus offshore) on sleep patterns were more marked than those of the two different shift systems (weekly rotation and fast rotation) in operation onshore. Age was negatively related to both duration and quality of sleep; over and above age, number of years of shiftwork was negatively related to sleep duration. Neuroticism was also negatively related to sleep duration and, more strongly, to sleep quality. These findings are discussed in relation to the literature on shiftwork and sleep in general, and the characteristics of the offshore environment in particular.

Age and gender differences in children’s and adolescents’ adaptation to sexual abuse

Objective: How children manifest psychological distress following the discovery of sexual abuse requires a better understanding of individual differences in developmental capacities and vulnerabilities. This study examined how age at the time of the abuse discovery and gender of victim are related to psychological distress. Method: One hundred and sixty-nine participants (96 children, 73 adolescents) were interviewed within 8 weeks of discovery of the abuse. Multivariate analyses were used to examine how age at discovery, and gender, with abuse characteristics as covariates, were related to shame, attribution style, depression, self-esteem, and traumatic events sequelae. Results: Adolescents compared to children report a higher level of depressive symptoms, negative reactions by others, and lower levels of self-esteem, social support, and sexual anxiety. Girls compared to boys report higher levels of intrusive thoughts, hyperarousal, sexual anxiety, personal vulnerability, and perceiving the world as a dangerous place and lower levels of eroticism. Conclusions: These findings suggest the importance of considering individual differences in age and gender for understanding patterns of symptom expression. Treatment strategies need to reflect these individual differences in adjustment, such as targeting issues of sexual anxiety for girls and self-esteem for adolescents.

Postsurgical Pain Is Attenuated in Men with Elevated Presurgical Systolic Blood Pressure

Previous research has demonstrated that elevated resting blood pressure is associated with a decreased perception of experimental pain. To assess this relationship in the context of clinical pain, postsurgical pain ratings were obtained from 159 men recovering from radical prostatectomy. Participants ranged in age from 46 to 75 years (Mean=61.9, SD=5.9), and on admission to the hospital had mean systolic and diastolic blood pressures of 134.2/79.9 mmHg (SD=19.2/10.2). Pain ratings were obtained at 24 h and 48 h postsurgery using the McGill Pain Questionnaire and Visual Analog Scales administered at rest and after standardized movement (VAS‐M). Results of correlational analyses indicated that higher preoperative resting systolic blood pressure was associated with significantly lower VAS‐M pain ratings at 24 h postsurgery and significantly lower ratings on all pain measures at 48 h postsurgery. The relationships between blood pressure and pain ratings were maintained even after controlling for individual differences in age, length of surgery and postsurgical self‐administration of morphine. These results confirm and extend previous observations of decreased pain in individuals with elevated blood pressure and suggest that this effect persists despite access to morphine analgesia.

Genes control the cessation of a woman's reproductive life: a twin study of hysterectomy and age at menopause.

A classical twin study was performed to assess the extent to which genetic factors explain individual differences in age at menopause and (indications for) hysterectomy. It was further examined whether a genetic effect on the timing of the menopause was mediated through a genetic effect on age at menarche. The subjects were 275 monozygotic and 353 dizygotic female twin pairs. Maximum likelihood model fitting was used to estimate genetic and environmental variance components, Kaplan-Meier survival analysis was used to account for censored data, and the Cox proportional hazards model was used to adjust for potential confounders. A model specifying additive genetic and unique environmental factors showed the best fit to the data, yielding a heritability (h2) for age at menopause of 63%. The significance of the genetic effect was confirmed by the survival analysis and was not affected by adjustment for confounders. Both early and late menopause were found to be significantly influenced by genetic factors. Hysterectomy also showed considerable heritability (h2 = 59%), as did its two main indications: fibroids (h2 = 69%) and menorrhagia (h2 = 55%). The genetic contribution to the variance in age at menarche was estimated to be 45%, with the majority (37%) being due to dominant genetic effects. No correlation was found between age at menopause and age at menarche, suggesting different genetic mechanisms. This study provides convincing evidence for the importance of genetic factors in determining natural and surgical menopause. Understanding how genes control the timing of menopause and exploring whether these genes are indirectly associated with disease are important areas for future study.

Respiratory Changes due to Long-term Exposure to Urban Levels of Air Pollution: A Histopathologic Study in Humans

To evaluate the potential associations between long-term exposure to air pollution and histopathologic evidence of damage to the lungs in humans. Lung tissue samples were collected during necropsies of individuals who died due to violent causes, selected on the basis of their exposure background. The exposed group was composed of individuals who lived in Guarulhos, an area with high mean levels of inhalable particles. The control group was composed of individuals who lived in two cities with economies based on agricultural activities: Ribeirão Preto and Ourinhos. Information about cigarette smoking and occupational exposure was obtained from family members. Morphometric evaluation of the main bronchus was conducted to determine the volume ratio of submucosal glands. Histopathologic alterations of the bronchioli were evaluated by scoring the presence of inflammatory reaction, wall thickening, and secretory hyperplasia. The number of spots of carbon deposition was counted along the regions of lymphatic drainage (visceral pleura and axial connective tissue around bronchi and blood vessels). Statistical analysis was done by means of regression models controlled for age, smoking, and occupational exposure. Lungs collected from the high pollution area presented evidence of more histopathologic damage in comparison to those from the clean environments. These effects were observed even after controlling for individual differences in age, sex, and cigarette smoking levels. These results suggest that long-term exposure to air pollution may contribute to the pathogenesis of airway disease, and that urban levels of air pollution have adverse effects on the respiratory tract.

Assessing literacy in science: Evaluation of scientific news briefs

Media reports of scientific research are a pervasive and important source of new scientific knowledge. Evaluating conclusions found in those reports is an important form of scientific literacy. We examined the types of requests for information made by university students as they evaluated scientific news briefs. Students generated a variety of requests for information, focusing most often on how the research was conducted and why the results might have occurred. Fewer requests were made for information about what was found, who conducted the research, and where it was conducted. Least frequent were requests about related research. This pattern of findings may reflect emphasis of instruction in science classrooms. Requests appeared to be influenced by three dimensions of news briefs: plausibility of the conclusions; typicality (the degree to which the phenomena described are typical in biology, chemistry, and physics); and personal familiarity with the phenomena. Individual differences in age, number of science courses completed in university, and degree of belief in paranormal events were correlated with the types of requests made. Models of the evaluative process are needed to gain additional insights into how students' knowledge, dimensions of text, and personal characteristics interact in the course of learning. © 1997 John Wiley & Sons, Inc.

Knowledge of self, mother, and father in preterm and full-term toddlers

Full-term and preterm toddler's featural knowledge of self, mother, and father was assessed in relation to individual differences in age, attachment status, and cognitive ability. No relation was found between infants' knowledge of self and the predictor variables at 13 months. Different factors, however, were related to infants' knowledge of mothers' and fathers' features. Hierarchical regressions revealed that at 20 months, after controlling for the relation between complexity of knowledge and MDI Bayley scores, full-term infants who were securely attached to their mothers demonstrated more complex knowledge of her than insecurely attached infants or premature Infants' knowledge of self at 20 months and father at both 13 and 20 months was significantly related to attachment status but not term status. These data are discussed in the context of possible differential influences of term status on infant-mother and infant-father interactions.

The use of animal models to study the effects of aging on cognition.

This review addresses the importance of animal models for understanding the effects of normal aging on the brain and cognitive functions. First, studies of laboratory animals can help to distinguish between healthy aging and pathological conditions that may contribute to cognitive decline late in life. Second, research on individual differences in aging, a theme of interest in studies of elderly human beings, can be advanced by the experimental control afforded in the use of animal models. The review offers a neuropsychological framework to compare the effects of aging in human beings, monkeys, and rodents. We consider aging in relation to the role of the medial temporal lobe in memory, the information processing functions of the prefrontal cortex in the strategic use of memory, and the regulation of attention by distributed neural circuitry. We also provide an overview of the neurobiological effects of aging that may account for alterations in psychological functions.

Antecedents of adult interpersonal functioning: Effects of individual differences in age 3 temperament.

Antecedents of adult interpersonal functioning: Effects of individual differences in age 3 temperament.

Individual differences in aging: Implications for stereological studies of neuron loss

Individual differences in aging: Implications for stereological studies of neuron loss

Neurobiological substrates of behavioral decline: Models and data analytic strategies for individual differences in aging

Neurobiological substrates of behavioral decline: Models and data analytic strategies for individual differences in aging

Age, information processing speed, and intelligence.

Two parallel, but independent, literatures have grown out of observations that individual differences in information processing speed, as expressed in performance on choice reaction time (C RT) tasks, modestly correlate with individual differences in age and IQ test performance. These associations have prompted theories that individual differences in information processing speed functionally determine individual differences in performance of all cognitive skills by people of different general intellectual ability (Eysenck, 1986; Jensen, 1985) or age (Salthouse, 1982, 1985). The experiments on which this literature has been based suffer from methodological weaknesses, such that comparisons have only been made very early in practice and have only concerned mean latencies for correct responses. An experiment compared 90 volunteers aged from 50 through 79 years who were grouped in terms of their performance on the AH 4 (Heim, 1968) IQ test. It explored the joint and independent effects of individual differences in age and in IQ test score and the effects of practice on mean latencies (C RTs) on the shapes of distributions of correct and incorrect responses and on the limiting speeds with which accurate responses can be made (speed/error trade-off functions). We suggest that a plausible explanation for the results is that individual differences in age and in general ability influence C RTs mainly because they affect the efficiency with which responses can be controlled to maximize speed while maintaining accuracy.