Individual Differences In Change Research Articles

A longitudinal twin study of callous-unemotional traits during childhood.

Previous research indicates that genetic factors largely account for the stability of callous-unemotional (CU) traits in adolescence. However, the genetic-environmental etiology of the development of CU traits has not been extensively investigated in childhood, despite work showing the reliable measurement and stability of CU traits from a young age. The aim of this study was to investigate the temporal pattern of genetic and environmental etiology of CU traits across primary school, from school entry (7 years) to middle (9 and 10 years) and late childhood (12 years). Data were collected in a population sample of twins composed of 662 twin pairs (Quebec Newborn Twin Study). CU traits were reported by teachers and analyzed using a biometric latent growth curve model and a Cholesky decomposition model. Latent growth curve analyses revealed that genetic factors explain most of the variance in the intercept of CU traits. Individual differences in change over time were not significant. The Cholesky model revealed that genetic factors at 7 years had enduring contributions to CU traits at 9, 10, and 12 years. New, modest genetic contributions appeared at 9 and 10 years. Nonshared environmental contributions were generally age-specific. No shared environmental contributions were detected. In sum, both modeling approaches showed that genetic factors underlie CU traits during childhood. Initial and new genetic contributions arise during this period. Environments have substantial contributions, over and above genetic factors. Future research should investigate the source of genetic risk associated with CU traits. (PsycINFO Database Record

Precision, Reliability, and Effect Size of Slope Variance in Latent Growth Curve Models: Implications for Statistical Power Analysis.

Latent Growth Curve Models (LGCM) have become a standard technique to model change over time. Prediction and explanation of inter-individual differences in change are major goals in lifespan research. The major determinants of statistical power to detect individual differences in change are the magnitude of true inter-individual differences in linear change (LGCM slope variance), design precision, alpha level, and sample size. Here, we show that design precision can be expressed as the inverse of effective error. Effective error is determined by instrument reliability and the temporal arrangement of measurement occasions. However, it also depends on another central LGCM component, the variance of the latent intercept and its covariance with the latent slope. We derive a new reliability index for LGCM slope variance—effective curve reliability (ECR)—by scaling slope variance against effective error. ECR is interpretable as a standardized effect size index. We demonstrate how effective error, ECR, and statistical power for a likelihood ratio test of zero slope variance formally relate to each other and how they function as indices of statistical power. We also provide a computational approach to derive ECR for arbitrary intercept-slope covariance. With practical use cases, we argue for the complementary utility of the proposed indices of a study's sensitivity to detect slope variance when making a priori longitudinal design decisions or communicating study designs.

The neural determinants of age-related changes in fluid intelligence: a pre-registered, longitudinal analysis in UK Biobank

Background: Fluid intelligence declines with advancing age, starting in early adulthood. Within-subject declines in fluid intelligence are highly correlated with contemporaneous declines in the ability to live and function independently. To support healthy aging, the mechanisms underlying these declines need to be better understood. Methods: In this pre-registered analysis, we applied latent growth curve modelling to investigate the neural determinants of longitudinal changes in fluid intelligence across three time points in 185,317 individuals (N=9,719 two waves, N=870 three waves) from the UK Biobank (age range: 39-73 years). Results: We found a weak but significant effect of cross-sectional age on the mean fluid intelligence score, such that older individuals scored slightly lower. However, the mean longitudinal slope was positive, rather than negative, suggesting improvement across testing occasions. Despite the considerable sample size, the slope variance was non-significant, suggesting no reliable individual differences in change over time. This null-result is likely due to the nature of the cognitive test used. In a subset of individuals, we found that white matter microstructure (N=8839, as indexed by fractional anisotropy) and grey-matter volume (N=9931) in pre-defined regions-of-interest accounted for complementary and unique variance in mean fluid intelligence scores. The strongest effects were such that higher grey matter volume in the frontal pole and greater white matter microstructure in the posterior thalamic radiations were associated with higher fluid intelligence scores. Conclusions: In a large preregistered analysis, we demonstrate a weak but significant negative association between age and fluid intelligence. However, we did not observe plausible longitudinal patterns, instead observing a weak increase across testing occasions, and no significant individual differences in rates of change, likely due to the suboptimal task design. Finally, we find support for our preregistered expectation that white- and grey matter make separate contributions to individual differences in fluid intelligence beyond age.

Changes in Jail Inmates’ community connectedness across the period of incarceration

ABSTRACTJails bring inmates into proximity with one another and separate them from the community. Because inmates’ connectedness to one another and to the community influences post-release functioning, understanding risk factors for maladaptive shifts in connectedness may inform interventions. The current study examined changes in jail inmates’ (N = 203) connectedness to the community at large and to the criminal community, and predictors of individual differences in changes over time. Connectedness to both communities did not change on average during incarceration, but younger and less guilt-prone inmates increased more in connectedness to the criminal community than older and more guilt-prone inmates, suggesting connectedness interventions should target individuals exhibiting this constellation of attributes.

Stability and change in mother-child planning over middle childhood.

This longitudinal research examines maternal and child behaviors during joint planning over a 3-year period of middle childhood. 118 mother-child dyads were observed once a year beginning when the children were 8 years of age. Coding focused on mother and child planning behaviors, maternal instructional support, and child task engagement. Multilevel modeling was used to compare 3 models of stability and change: stability, normative developmental change, and individual differences in change. Results indicate that normative developmental change was the best predictor of mother and child planning behaviors and maternal guidance. Individual differences in rate of change predicted mothers' instructional support in the use of physical demonstration and child engagement measured by attention, task responsibility, and cooperation. Task difficulty contributed to these patterns. This research advances understanding of social interaction on cognitive tasks for partners in an established relationship. Implications for theory and future research are discussed. (PsycINFO Database Record

Changes in Life Satisfaction in the Retirement Transition: Interaction Effects of Transition Type and Individual Resources

The impact of retirement on well-being varies between individuals, but also within individuals over time. Type of transition and individual differences in resource capability are two factors likely to influence the retirement adjustment process, but we still lack in our understanding of the importance of these factors in relation to each other. 'I he aim of this study was to investigate interaction effects of transition type and individual resources on changes in life satisfaction in the retirement transition. We studied changes in life satisfaction over 1 year in a sample of 3,471 older adults from the population-based HEalth, Ageing, and Retirement Transitions in Sweden (HEARTS) study. The sample included participants retiring gradually (n = 360) or fully (n = 346) between the two measurement points as well those continuously working (n = 1,860) or retired (n = 905) in both waves. Resources evaluated for their role in the transition included baseline measures of self-esteem, autonomy, social support, self-rated physical health, self-rated cognitive ability, and basic financial assets. Results from multiple group latent change score models showed that retirement transition type and individual differences in resource capability variously influenced changes in life satisfaction. The six resources accounted for a larger proportion of individual differences in change among those who retired between the two waves (21.2%) than in those whose retirement status remained unchanged (12.6%). In addition, a larger proportion of variability in changes in life satisfaction were explained in abrupt (31.4%) than in gradual (11.7%) retirement.

Vocational interests across 20 years of adulthood: Stability, change, and the role of work experiences

Vocational interests demonstrate high rank-order stability during childhood and adolescence. However, few studies have investigated the development of vocational interests into adulthood. The present study examined rank-order and profile stability, mean-level and correlated change, and individual differences in change in RIASEC scores across 20years of adulthood. In addition, life events were examined as moderators of change. Rank-order stability was strong across vocational interest dimensions. Mean-level changes also occurred, with increases in Realistic interests and decreases in Investigative interests for men, increases in Enterprising interests for women, and decreases in Artistic interests for men and women. Individual differences in change indicated that not everyone changed in the same manner, with occupational experiences, such as job loss, related to greater change.

Individual differences in personality change across the adult life span.

A precise and comprehensive description of personality continuity and change across the life span is the bedrock upon which theories of personality development are built. Little research has quantified the degree to which individuals deviate from mean-level developmental trends. In this study, we addressed this gap by examining individual differences in personality trait change across the life span. Data came from a nationally representative sample of 9,636 Dutch participants who provided Big Five self-reports at five assessment waves across 7 years. We divided our sample into 14 age groups (ages 16-84 at initial measurement) and estimated latent growth curve models to describe individual differences in personality change across the study period for each trait and age group. Across the adult life span, individual differences in personality change were small but significant until old age. For Openness, Conscientiousness, Extraversion, and Agreeableness, individual differences in change were most pronounced in emerging adulthood and decreased throughout midlife and old age. For Emotional Stability, individual differences in change were relatively consistent across the life span. These results inform theories of life span development and provide future directions for research on the causes and conditions of personality change.

Genetic influences on individual differences in longitudinal changes in global and subcortical brain volumes: Results of the ENIGMA plasticity working group.

Structural brain changes that occur during development and ageing are related to mental health and general cognitive functioning. Individuals differ in the extent to which their brain volumes change over time, but whether these differences can be attributed to differences in their genotypes has not been widely studied. Here we estimate heritability (h2 ) of changes in global and subcortical brain volumes in five longitudinal twin cohorts from across the world and in different stages of the lifespan (N = 861). Heritability estimates of brain changes were significant and ranged from 16% (caudate) to 42% (cerebellar gray matter) for all global and most subcortical volumes (with the exception of thalamus and pallidum). Heritability estimates of change rates were generally higher in adults than in children suggesting an increasing influence of genetic factors explaining individual differences in brain structural changes with age. In children, environmental influences in part explained individual differences in developmental changes in brain structure. Multivariate genetic modeling showed that genetic influences of change rates and baseline volume significantly overlapped for many structures. The genetic influences explaining individual differences in the change rate for cerebellum, cerebellar gray matter and lateral ventricles were independent of the genetic influences explaining differences in their baseline volumes. These results imply the existence of genetic variants that are specific for brain plasticity, rather than brain volume itself. Identifying these genes may increase our understanding of brain development and ageing and possibly have implications for diseases that are characterized by deviant developmental trajectories of brain structure. Hum Brain Mapp 38:4444-4458, 2017. © 2017 Wiley Periodicals, Inc.

A longitudinal twin study of general cognitive ability over four decades.

In this longitudinal study we examined the stability of general cognitive ability (GCA), as well as heterogeneity and genetic and environmental influences underlying individual differences in change. We investigated GCA from young adulthood through late midlife in 1,288 Vietnam Era Twin Study of Aging participants at ages ∼20, ∼56, and ∼62 years. The correlations among the 3 occasions ranged from .73 to .85, reflecting substantial stability. The heritability was significant on each of the 3 occasions and ranged from .59 to .66. The influence of the shared environment was not significant at any of the ages. The genetic correlations across the 3 occasions ranged from .95 to .99 and did not differ significantly from 1.0. The nonshared environmental correlations ranged from .21 to .47. Latent growth curve analysis was applied to characterize trajectories over the 42-year period. Slope was significantly different from 0 and indicated that there was modest change over time. There was a significant genetic influence on initial level of GCA (h2 = .67), but not change (h2 = .23). Genetic factors primarily contribute to stability, while change reflects the influence of nonshared environmental influences. There was a significant negative correlation between initial level of GCA and change (r = -.31). Latent class growth analysis identified 4 trajectories. In general, the 4 groups followed parallel trajectories and were differentiated mainly by differences in AFQT performance level at the time of military induction. (PsycINFO Database Record

The association of ADHD symptoms and reading acquisition during elementary school years.

The present longitudinal study aimed to investigate the influence of ADHD symptoms on reading development in elementary schoolchildren. To this end, repeated assessments of ADHD symptoms (teacher ratings of inattention, hyperactivity, and impulsivity) and reading achievement (standardized tests of decoding speed and text comprehension) were examined in a sample comprising 2,014 elementary schoolchildren at the end of Grades 1, 2, 3, respectively, and in the middle of Grade 4. Latent change score models revealed that the level of ADHD symptoms was associated with lower levels and less growth in decoding speed and text comprehension. Furthermore, individual differences in changes in ADHD symptoms and reading performance were negatively associated. Together, these results indicate commonalities in the development of ADHD symptomatology and reading achievement throughout elementary school. (PsycINFO Database Record

Cortical thickness change in autism during early childhood.

Structural magnetic resonance imaging (MRI) scans at high spatial resolution can detect potential foci of early brain dysmaturation in children with autism spectrum disorders (ASD). In addition, comparison between MRI and behavior measures over time can identify patterns of brain change accompanying specific outcomes. We report structural MRI data from two time points for a total of 84 scans in children with ASD and 30 scans in typical controls (mean age time one = 4.1 years, mean age at time two = 6.6 years). Surface-based cortical morphometry and linear mixed effects models were used to link changes in cortical anatomy to both diagnostic status and individual differences in changes in language and autism severity. Compared with controls, children with ASD showed accelerated gray matter volume gain with age, which was driven by a lack of typical age-related cortical thickness (CT) decrease within 10 cortical regions involved in language, social cognition, and behavioral control. Greater expressive communication gains with age in children with ASD were associated with greater CT gains in a set of right hemisphere homologues to dominant language cortices, potentially identifying a compensatory system for closer translational study. Hum Brain Mapp 37:2616-2629, 2016. © 2016 Wiley Periodicals, Inc.

Pulse Pressure Magnifies the Effect of COMT Val158Met on 15 Years Episodic Memory Trajectories

We investigated whether a physiological marker of cardiovascular health, pulse pressure (PP), and age magnified the effect of the functional COMT Val158Met (rs4680) polymorphism on 15-years cognitive trajectories [episodic memory (EM), visuospatial ability, and semantic memory] using data from 1585 non-demented adults from the Betula study. A multiple-group latent growth curve model was specified to gauge individual differences in change, and average trends therein. The allelic variants showed negligible differences across the cognitive markers in average trends. The older portion of the sample selectively age-magnified the effects of Val158Met on EM changes, resulting in greater decline in Val compared to homozygote Met carriers. This effect was attenuated by statistical control for PP. Further, PP moderated the effects of COMT on 15-years EM trajectories, resulting in greater decline in Val carriers, even after accounting for the confounding effects of sex, education, cardiovascular diseases (diabetes, stroke, and hypertension), and chronological age, controlled for practice gains. The effect was still present after excluding individuals with a history of cardiovascular diseases. The effects of cognitive change were not moderated by any other covariates. This report underscores the importance of addressing synergistic effects in normal cognitive aging, as the addition thereof may place healthy individuals at greater risk for memory decline.

The Development of Self-Representations During the Transition to Early Adolescence: The Role of Gender, Puberty, and School Transition

The present study investigated the development of global and domain-specific self-representations in the transition from late childhood to early adolescence and tested whether gender, puberty, and school transition help explain individual differences in change. The study was based on three measurement occasions over 2 years and included 248 adolescents (average age at T1 = 10.6 years). Findings indicated both stability and change over time. Individual differences in change were partially explained by gender and school transition. It revealed that girls experienced steeper decreasing trajectories and were more negatively affected by school transition in comparison with boys. Time-varying associations between puberty and self-representations were evident in terms of perceived pubertal timing. Findings suggest that both biological (pubertal timing) and contextual factors (school transition) play a role in explaining individual differences of self-representation level as well as their development in girls’ and boys’ transition to early adolescence.

Maintaining perceived control with unemployment facilitates future adjustment

Unemployment is a major challenge to individuals' development. An important personal resource to ameliorate the negative impact of unemployment may be perceived control, a general-purpose belief system. Little is known, however, about how perceived control itself changes with the experience of unemployment and what the antecedents, correlates, and consequences of such change in perceived control are in different ages. We use data from the German Socio-Economic Panel Study (N=413 who experienced unemployment and N=413 case-matched controls; time period of data collection: 1994–1996) to examine whether perceived control changes with unemployment, explore the role of socio-demographic, psychosocial and health factors in moderating such change, and investigate whether levels of perceived control prior to unemployment and unemployment-related change in perceived control predict unemployment-related outcomes up to five years following. Results indicated that, on average, perceived control remained relatively stable with unemployment, and that younger and older workers did not differ in this regard. However, there were sizeable individual differences in change in perceived control, with women and those with fewer years of education experiencing greater unemployment-related declines in perceived control. Lower levels of perceived control prior to unemployment and steeper unemployment-related decrements in perceived control were each associated with a higher risk of remaining unemployed in the 12months immediately following unemployment. Steeper unemployment-related declines in perceived control also predicted lower life satisfaction up to five years following. We discuss possible pathways by which perceived control may facilitate adjustment to unemployment, consider the role of perceived control for better understanding the dynamics of unemployment, and suggest routes for further more process-oriented inquiry.

Personality trait change across late childhood to young adulthood: Evidence for nonlinearity and sex differences in change.

We explored patterns of self-reported personality trait change across late childhood through young adulthood in a sample assessed up to 4 times on the lower-order facets of Positive Emotionality (PEM), Negative Emotionality (NEM), and Constraint (CON). Multilevel modeling analyses were used to describe both group- and individual-level change trajectories across this time span. There was evidence for nonlinear age-related change in most traits, and substantial individual differences in change for all traits. Gender differences were detected in the change trajectories for several facets of NEM and CON. Findings add to the literature on personality development by demonstrating robust nonlinear change in several traits across late childhood to young adulthood, as well as deviations from normative patterns of maturation at the earliest ages.

Regional brain shrinkage and change in cognitive performance over two years: The bidirectional influences of the brain and cognitive reserve factors

We examined relationships between regional brain shrinkage and changes in cognitive performance, while taking into account the influence of chronological age, vascular risk, Apolipoprotein E variant and socioeconomic status. Regional brain volumes and cognitive performance were assessed in 167 healthy adults (age 19–79 at baseline), 90 of whom returned for the follow-up after two years. Brain volumes were measured in six regions of interest (ROIs): lateral prefrontal cortex (LPFC), prefrontal white matter (PFw), hippocampus (Hc), parahippocampal gyrus (PhG), cerebellar hemispheres (CbH), and primary visual cortex (VC), and cognitive performance was evaluated in three domains: episodic memory (EM), fluid intelligence (Gf), and vocabulary (V). Average volume loss was observed in Hc, PhG and CbH, but reliable individual differences were noted in all examined ROIs. Average positive change was observed in EM and V performance but not in Gf scores, yet only the last evidenced individual differences in change. We observed reciprocal influences among neuroanatomical and cognitive variables. Larger brain volumes at baseline predicted greater individual gains in Gf, but differences in LPFC volume change were in part explained by baseline level of cognitive performance. In one region (PFw), individual change in volume was coupled with change in Gf. Larger initial brain volumes did not predict slower shrinkage. The results underscore the complex role of brain maintenance and cognitive reserve in adult development.

White matter and memory in healthy adults: Coupled changes over two years

Numerous cross-sectional studies have used diffusion tensor imaging (DTI) to link age-related differences in white matter (WM) anisotropy and concomitant decrements in cognitive ability. Due to a dearth of longitudinal evidence, the relationship between changes in diffusion properties of WM and cognitive performance remains unclear. Here we examine the relationship between two-year changes in WM organization and cognitive performance in healthy adults (N=96, age range at baseline=18–79 years). We used latent change score models (LCSM) to evaluate changes in age-sensitive cognitive abilities — fluid intelligence and associative memory. WM changes were assessed by fractional anisotropy (FA), axial diffusivity (AD), and radial diffusivity (RD) in WM regions that are considered part of established memory networks and exhibited individual differences in change. In modeling change, we postulated reciprocal paths between baseline measures and change factors, within and between WM and cognition domains, and accounted for individual differences in baseline age. Although baseline cross-sectional memory performance was positively associated with FA and negatively with RD, longitudinal effects told an altogether different story. Independent of age, longitudinal improvements in associative memory were significantly associated with linear reductions in FA and increases in RD. The present findings demonstrate the sensitivity of DTI-derived indices to changes in the brain and cognition and affirm the importance of longitudinal models for evaluating brain-cognition relations.

Is residual memory variance a valid method for quantifying cognitive reserve? A longitudinal application

Cognitive reserve describes the mismatch between brain integrity and cognitive performance. Older adults with high cognitive reserve are more resilient to age-related brain pathology. Traditionally, cognitive reserve is indexed indirectly via static proxy variables (e.g., years of education). More recently, cross-sectional studies have suggested that reserve can be expressed as residual variance in episodic memory performance that remains after accounting for demographic factors and brain pathology (whole brain, hippocampal, and white matter hyperintensity volumes). The present study extends these methods to a longitudinal framework in a community-based cohort of 244 older adults who underwent two comprehensive neuropsychological and structural magnetic resonance imaging sessions over 4.6 years. On average, residual memory variance decreased over time, consistent with the idea that cognitive reserve is depleted over time. Individual differences in change in residual memory variance predicted incident dementia, independent of baseline residual memory variance. Multiple-group latent difference score models revealed tighter coupling between brain and language changes among individuals with decreasing residual memory variance. These results suggest that changes in residual memory variance may capture a dynamic aspect of cognitive reserve and could be a useful way to summarize individual cognitive responses to brain changes. Change in residual memory variance among initially non-demented older adults was a better predictor of incident dementia than residual memory variance measured at one time-point.

Patterns and sources of personality development in old age.

Despite abundant evidence that personality development continues in adulthood, little is known about the patterns and sources of personality development in old age. We thus investigated mean-level trends and individual differences in change as well as the genetic and environmental sources of rank-order continuity and change in several personality traits (neuroticism, extraversion, openness, agreeableness, conscientiousness, perceived control, and affect intensity) and well-being. In addition, we analyzed the interrelation between perceived control and change in other personality traits as well as between change in personality traits and change in well-being. We analyzed data from older adult twins, aged 64-85 years at Time 1 (N = 410; 135 males and 275 females; 134 monozygotic and 63 dizygotic twin pairs), collected at 2 different time points about 5 years apart. On average, neuroticism increased, whereas extraversion, conscientiousness, and perceived control significantly decreased over time. Change in perceived control was associated with change in neuroticism and conscientiousness, pointing to particular adaptation mechanisms specific to old age. Whereas individual differences in personality traits were fairly stable due to both genetic and environmental sources, individual differences in change were primarily due to environmental sources (beyond random error) indicating plasticity in old age. Even though the average level of well-being did not significantly change over time, individual well-being tended to decrease with strongly increasing levels of neuroticism as well as decreasing extraversion, conscientiousness, and perceived control, indicating that personality traits predict well-being but not vice versa. We discuss implications for theory on personality development across the lifespan.