Age-heterogeneous Samples Research Articles

Too Old for Agility? Employee Age and Readiness for Change Toward Scrum—The Moderating Roles of Age Climate and Subjective Age

AbstractWhile demographic change is leading to an aging workforce in many parts of the world, more and more companies are implementing agile forms of collaboration. These enable better adaptation to change through constant, iterative learning but require a corresponding mindset from the employees. According to meta-analytical findings, willingness to learn is negatively correlated with employee age, whereas willingness to change is not. We examined the relationship between employee age and readiness for change toward Scrum—the predominant framework of agile project management—focusing on moderating effects. We hypothesized that readiness for Scrum does not decrease with employee age per se, but that it depends on age climate and subjective age. Using an animated explainer video, we created a scenario in which Scrum gets implemented in the participants’ work area. We tested our hypotheses using two studies with age-heterogeneous samples (N1 = 146, N2 = 198), differing in their mean ages (M1 = 36.9, M2 = 41.6). Across studies, and consistent with expectations, readiness for Scrum increased with age when employees reported lower levels of subjective age. Regarding age climate, the results were mixed: In Study 1, readiness for Scrum increased with age when participants perceived a more negative age climate, whereas in Study 2, it increased in a more positive age climate. Results of the three-way interaction in Study 1 suggest a complex interplay between age identity and age climate. We interpret these results in light of existing theory and discuss possible implications for research and practice.

Using implicit association tests in age-heterogeneous samples: The importance of cognitive abilities and quad model processes.

Implicit association tests (IATs) are increasingly used to indirectly assess people's traits, attitudes, or other characteristics. In addition to measuring traits or attitudes, IAT scores also reflect differences in cognitive abilities because scores are based on reaction times (RTs) and errors. As cognitive abilities change with age, questions arise concerning the usage and interpretation of IATs for people of different age. To address these questions, the current study examined how cognitive abilities and cognitive processes (i.e., quad model parameters) contribute to IAT results in a large age-heterogeneous sample. Participants (N = 549; 51% female) in an age-stratified sample (range = 12-88 years) completed different IATs and 2 tasks to assess cognitive processing speed and verbal ability. From the IAT data, D2-scores were computed based on RTs, and quad process parameters (activation of associations, overcoming bias, detection, guessing) were estimated from individual error rates. Substantial IAT scores and quad processes except guessing varied with age. Quad processes AC and D predicted D2-scores of the content-specific IAT. Importantly, the effects of cognitive abilities and quad processes on IAT scores were not significantly moderated by participants' age. These findings suggest that IATs seem suitable for age-heterogeneous studies from adolescence to old age when IATs are constructed and analyzed appropriately, for example with D-scores and process parameters. We offer further insight into how D-scoring controls for method effects in IATs and what IAT scores capture in addition to implicit representations of characteristics. (PsycINFO Database Record

Supplemental Material for Using Implicit Association Tests in Age-Heterogeneous Samples: The Importance of Cognitive Abilities and Quad Model Processes

Supplemental Material for Using Implicit Association Tests in Age-Heterogeneous Samples: The Importance of Cognitive Abilities and Quad Model Processes

Breadth and age-dependency of relations between cortical thickness and cognition

Recent advances in neuroimaging have identified a large number of neural measures that could be involved in age-related declines in cognitive functioning. A popular method of investigating neural-cognition relations has been to determine the brain regions in which a particular neural measure is associated with the level of specific cognitive measures. Although this procedure has been informative, it ignores the strong interrelations that typically exist among the measures in each modality. An alternative approach involves investigating the number and identity of distinct dimensions within the set of neural measures and within the set of cognitive measures before examining relations between the 2 types of measures. The procedure is illustrated with data from 297 adults between 20 and 79 years of age with cortical thickness in different brain regions as the neural measures and performance on 12 cognitive tests as the cognitive measures. The results revealed that most of the relations between cortical thickness and cognition occurred at a general level corresponding to variance shared among different brain regions and among different cognitive measures. In addition, the strength of the thickness-cognition relation was substantially reduced after controlling the variation in age, which suggests that at least some of the thickness-cognition relations in age-heterogeneous samples may be attributable to the influence of age on each type of measure.

Structure and correlates of cognitive aging in a narrow age cohort.

Aging-related changes occur for multiple domains of cognitive functioning. An accumulating body of research indicates that, rather than representing statistically independent phenomena, aging-related cognitive changes are moderately to strongly correlated across domains. However, previous studies have typically been conducted in age-heterogeneous samples over longitudinal time lags of 6 or more years, and have failed to consider whether results are robust to a comprehensive set of controls. Capitalizing on 3-year longitudinal data from the Lothian Birth Cohort of 1936, we took a longitudinal narrow age cohort approach to examine cross-domain cognitive change interrelations from ages 70 to 73 years. We fit multivariate latent difference score models to factors representing visuospatial ability, processing speed, memory, and crystallized ability. Changes were moderately interrelated, with a general factor of change accounting for 47% of the variance in changes across domains. Change interrelations persisted at close to full strength after controlling for a comprehensive set of demographic, physical, and medical factors including educational attainment, childhood intelligence, physical function, APOE genotype, smoking status, diagnosis of hypertension, diagnosis of cardiovascular disease, and diagnosis of diabetes. Thus, the positive manifold of aging-related cognitive changes is highly robust in that it can be detected in a narrow age cohort followed over a relatively brief longitudinal period, and persists even after controlling for many potential confounders.

Short assessment of the Big Five: robust across survey methods except telephone interviewing

We examined measurement invariance and age-related robustness of a short 15-item Big Five Inventory (BFI–S) of personality dimensions, which is well suited for applications in large-scale multidisciplinary surveys. The BFI–S was assessed in three different interviewing conditions: computer-assisted or paper-assisted face-to-face interviewing, computer-assisted telephone interviewing, and a self-administered questionnaire. Randomized probability samples from a large-scale German panel survey and a related probability telephone study were used in order to test method effects on self-report measures of personality characteristics across early, middle, and late adulthood. Exploratory structural equation modeling was used in order to test for measurement invariance of the five-factor model of personality trait domains across different assessment methods. For the short inventory, findings suggest strong robustness of self-report measures of personality dimensions among young and middle-aged adults. In old age, telephone interviewing was associated with greater distortions in reliable personality assessment. It is concluded that the greater mental workload of telephone interviewing limits the reliability of self-report personality assessment. Face-to-face surveys and self-administrated questionnaire completion are clearly better suited than phone surveys when personality traits in age-heterogeneous samples are assessed.

Evaluating Convergence of Within-Person Change and Between-Person Age Differences in Age-Heterogeneous Longitudinal Studies

The distinction of between-person age differences from within-person age changes is necessary for understanding aging-related change processes. Although longitudinal studies are required to address issues relating to within-person change, most studies begin using age-heterogeneous samples and conclude using survival-heterogeneous samples. Given the numerous potential confounds associated with age-heterogeneous samples, careful treatment of between-person age differences is essential to obtain the correct inferences regarding within-person age change. The authors demonstrate how failure to differentiate between-person age effects (and by extension, of survival age or other effects producing sample heterogeneity) will lead to uninterpretable inferences regarding within-person change. The authors recommend that convergence of age differences and age changes be formally evaluated whenever possible.

Examination of the processing speed account in a population‐based longitudinal study with narrow age cohort design

The processing speed account suggests that general slowing of mental processing speed results in an overall decline, especially age-related decline, in other cognitive domains. Support for the speed account comes mainly from cross-sectional studies with participants that vary in age (age-heterogeneous samples). This study investigated how well variations in processing speed predict change of episodic recall in a longitudinal framework and examined with the Narrow Age Cohort (NAC) design. Data were obtained from Betula, a population-based longitudinal study. Both 5-year (n= 490; Time 3 - Time 4) and 10-year follow-up results (n= 608; Time 1 - Time 3) were used. In both samples, which were subjected to prospective dementia screening, we found considerably weaker associations in longitudinal data compared to cross-sectional, and also weaker associations in age-homogeneous than in age-heterogeneous samples. The results provide little support for the speed account.

Determining neuropsychological cut scores for older, healthy adults.

Three age groups (20-31, 37-49, and 55-67 years) of healthy men and women were compared on tests from the Halstead-Reitan neuropsychological test battery. Age-cohort differences in performance were observed for every measure (except Finger Tapping) and for overall indices of cognitive functioning, the Average Impairment Rating (AIR) and the Halstead-Reitan Impairment Index (HR II). When traditional cut scores (developed with age-heterogeneous samples) were used, alarmingly high percentages of subjects in the oldest group were defined as brain damaged. These findings were not attributable to higher levels of psychometrically-assessed anxiety and depression in the older groups or for the impaired subjects. Slightly more conservative criteria (fewer diagnoses of brain impairment) were then employed. The first, AIR greater than or equal to 2.00, resulted in a low and more reasonable base rate of brain impairment for the oldest group. The second, AIR greater than 2.00, resulted in age-parity in incidence of brain impairment. The heuristic value of more conservative AIR scores was discussed as were possible uses in applied clinical research settings. The limitations of this approach were noted with regard to its exclusive focus on the problem of false positive diagnoses. It was emphasized that, from a neuropsychological diagnostic perspective, cut scores based on healthy aging samples must ultimately be tested in the context of traditional neuropsychological studies in which external validation with neurosurgical and neurological criteria is employed.

Search for a Common Cause Factor amongst Cognitive, Speed and Biological Variables Using Narrow Age Cohorts

Background: Cross-sectional studies have demonstrated that age-related effects on many cognitive and biological functioning variables are shared. A number of theories postulate that these associations arise from a common causal mechanism responsible for change across a wide range of functions. However, it has been claimed that the finding of shared variance among variables in these studies may be spurious because most studies have been cross-sectional and based on age-heterogeneous samples. Objective: To examine evidence for changes with age in variance shared by cognitive variables using a narrow-age cohort design. Methods: Three samples of adults with age ranges 20–24 years (n = 2,404), 40–44 years (n = 2,530) and 60–64 years (n = 2,510) were drawn from a population-based study. These groups were supplemented by data from an older sample of individuals (77 years and over) from a second population-based study (n = 374). Four models of the structure of a range of cognitive, speed and biological variables derived from previous cross-sectional research were fitted to data. These models were complete independence of variables within a cohort, a single common factor, multiple independent factors, and a second order factor model. Results: Model fit and the magnitude of loadings from multiple-group confirmatory factor analyses was compared between age groups. The fit for all four models was worse in the 60–64 year age group. Factor loadings on the common factor specified in these models varied between the groups, but the speed factor rather than the biological factor showed increased loadings as a function of age. Conclusions: This narrow age-cohort study did not support the existence of developmental changes in the structure of cognitive and biological variables across the lifespan. Shared variation between measures of cognition and biological function may be an artifact of the research designs that have generated these findings. This casts doubt of the existence of a common causal mechanism. However, it may be that such changes manifest only in later old age.

Cross-Sectional Analysisof Time-Dependent Data: Mean-Induced Association in Age-Heterogeneous Samples and an Alternative Method Based on Sequential NarrowAge-Cohort Samples

The effect of time-related mean differences on estimates of association in cross-sectional studies has not been widely recognized in developmental and aging research. Cross-sectional studies of samples varying in age have found moderate to high levels of shared age-related variance among diverse age-related measures. These findings may be misleading because high levels of association between time-dependent processes can result simply from average population age differences and not necessarily from associations between individual "rates of aging." This is demonstrated both analytically and in a simulation involving cross-sectional sampling of individual trajectories. An alternative cross-sectional narrow age-cohort design is shown to provide a useful alternative for evaluating the interdependence of time-related processes.

Exploring structural dynamics within and between sensory and intellectual functioning in old and very old age: Longitudinal evidence from the Berlin Aging Study

Abstract Cross-sectional and longitudinal analyses of age-heterogeneous samples have revealed correlational links between and within intellectual, sensory, and sensorimotor domains. Due to basic limitations of cross-sectional designs and a reluctance to disentangle antecedent–consequent relations in longitudinal designs, the functional significance and dynamics of these links have remained unclear. Advanced structural equation models allow representing multivariate longitudinal changes as a function of time-based and directed relations. We applied this methodology to longitudinal data from the Berlin Aging Study (at inception total N = 516; age range = 70–103 years) to explore the structural dynamics among perceptual speed, verbal knowledge, close visual acuity, and distance visual acuity. We found reliable, occasion-based, age-partialed latent regression paths that influence longitudinal changes within and across intellectual and sensory domains. We conclude that intellectual and sensory domains are dynamically linked in old and very old age, and discuss implications of this finding for theories of cognitive aging.

Age Is Not Necessarily Aging: Another Step towards Understanding the ‘Clocks’ That Time Aging

Hofer and Sliwinski raise a critical concern regarding a popular practice in aging research of inferring associations among aging changes of different processes from correlations based on cross-sectional age differences. It is shown analytically that cross-sectional information drawn from age-heterogeneous samples is not suitable for answering questions about the interdependence between aging changes. While in general we agree with the problem pointed out by Hofer and Sliwinski, the two aims of this commentary are: (1) to highlight links between the specific concern and two long-standing issues confronting life-span researchers and (2) to introduce alternative approaches that are currently underutilized in gerontological research. We elaborate general issues with respect to challenges in inferring aging changes from age differences and using age as a proxy for aging. We show that several other sources of variance independent of rates of change, such as cohort- and mortality-related selection effects, are confounded in age-heterogeneous designs. We suggest general considerations for developing more explicit theories of cognitive aging in the future. Alternative research methods and paradigms for studying the causes and mechanisms of the aging mind at different time scales and levels are also highlighted. The role of chronological age in aging research is rather ‘superficial’. To understand the underlying processes and mechanisms of cognitive aging, classical process-oriented, rather than solely age-oriented, theoretical conceptions need to be reconsidered and reified with new methodological and empirical advances. Concerted gerontological research endeavors utilizing recent progresses made in statistical analyses of dynamic processes and in cognitive and computational neurosciences that may lead to fruitful breakthroughs.

A preliminary comparison of healthy elderly and young adults on the sunya revision of the psychosomatic symptom checklist

Elderly ( n = 30) and young ( n = 30) subjects, equated in terms of general physical health, education and depression, were compared in terms of Total, Frequency and Intensity scores on the psychosomatic symptom checklist (PSC). Elderly subjects scored significantly lower than young subjects for both PSC Total and PSC Intensity scores. These results call into question the practice of aggregating PSC data from age heterogeneous samples and indicate the importance of reporting all three PSC scores.

Age: A Truly Confounding Variable

As Hinshaw (1981) has noted, the process of designing research might best be conceptualized as a series of informed decisions that involve constant trade-offs and compromise. With each advantage gained by a particular theoretical or methodological decision, the researcher inherits a certain number of threats to the study's internal and external validity and a potential number of error sources. Because of the nature of the research questions of interest to nurses and because of situational and contextual constraints in the clinical setting, nurse researchers often are required to select samples that contain small or large proportions of elderly subjects. The purpose of this article has been to raise some of the theoretical and methodological issues associated with the selection of both age-heterogeneous samples and age-homogeneous samples. Although in research all possible error sources cannot be controlled, it is possible to reduce the amount of error by a clear understanding of the implications of choices regarding age-related issues and inclusion of design features that reduce the amount of error introduced when research subjects who are relatively young are studied along with research subjects who are elderly.

The Reliability and Validity of Objective Indices of Moral Development

The present paper addresses three issues sur rounding Rest's Defining Issues Test, an objective test of moral development based on Kohlberg's six- stage theory of moral development. Those issues are (1) the stability of test scores over time; (2) correla tion of scores with Kohlberg's interview measure of moral development; and (3) the insensitivity of its scoring procedure, which ignores responses to all items keyed to lower stages. In two age heterogene ous samples, total score test-retest reliabilities were generally in the high .70's or low .80's, regardless of which of several scoring schemes was used. In another age heterogeneous sample, the correlation with scores on Kohlberg's test was .70; but in two age homogeneous samples, the correlations were about .35 and .20. These validity coefficients sug gest that (1) the common variance shared by Rest's and Kohlberg's tests in age heterogeneous samples can be attributed to the fact that scores on both tests increase with age and (2) the two tests cannot be considered equivalent measures of the same con struct differing only in format. Results also in dicated that an empirically weighted scoring scheme is more sensitive to longitudinal change than is Rest's P score. This sensitivity to longi tudinal trends is an important property for tests such as Rest's which claim to be developmental and are frequently used to assess educational change. The empirically weighted sum had a significantly higher test-retest reliability (p < .05) than did a simple sum of item responses, and it had a signifi cantly higher correlation with Kohlberg's measure than did a theoretically weighted sum.