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.     

Relationship between rigidity-flexibility and cognitive abilities in adulthood

The interrelationship of measures of rigidity-flexibility and of psychometric intelligence is examined. The latent factors of Attitudinal Flexibility, Motor-Cognitive Flexibility, and Psychomotor Speed are derived from the Test of Behavioral Rigidity, and factors of Inductive Reasoning, Spatial Orientation, Verbal Ability, Numeric Ability, Verbal Memory, and Perceptual Speed are derived from the Thurstone Primary Mental Abilities Test and the Educational Testing Service Kit of Factor-Referenced Tests. The data base in this study comes from the fifth wave of the Seattle Longitudinal Study (N = 1,628; age range, 22-95 years). The Rigidity-Flexibility factors were found to be independent of the cognitive domain. Also, longitudinal stability of the factor structure of the rigidity-flexibility domain was confirmed for 837 participants tested in both 1977 and 1984.     

Between- versus within-family factor analyses of cognitive abilities

Confirmatory factor analyses of the 15 cognitive abilities tests from the Hawaii Family Study of Cognition were conducted on between-family (BF) means and within-family (WF) differences for 370 AEA (Americans of European ancestry) and 116 AJA (Americans of Japanese ancestry) sibling pairs. Difference chi-square significance tests, goodness-of-fit indices, and congruence coefficients for the estimated loadings on four specific cognitive abilities factors and on the second-order general intelligence factor nearly all indicated that the between-family factor structures were not significantly different from the within-family structures for both AEA and AJA siblings (the AEA and AJA structures were also not significantly different). The similarity of the BF and WF structures suggests that the genetic and environmental influences underlying cognitive abilities are “intrinsic” in nature, that is, not just due to between-family differences in culture, status, values, and fortuitous cross-assortative mating.     

Developmental patterns in body esteem from late childhood to young adulthood: A growth curve analysis

This study examines the long-term development of different domains of body esteem (BE), the most salient domain of adolescents' global self-esteem. The 11-year longitudinal study of Swedish youths, covering ages 10–21, showed that BE undergoes significant change from late childhood to young adulthood, with growth curve models revealing different developmental paths between domains and across gender. For girls, general appearance esteem and weight esteem decreased in the early adolescent phase and then stabilized. For boys, similar patterns were evident, but weight esteem was subject to change also in late adolescence. The third BE domain, appearance-evaluations ascribed to others, displayed a distinct developmental trajectory. This was the only domain where no gender differences were noted in terms of mean levels. It was also the only domain that demonstrated positive increases over time. Findings from the present long-term study contribute to a more coherent picture of the development of BE from late childhood and into young adulthood.     

Latent growth curve analyses of peer and parent influences on smoking progression among early adolescents.

Social influences on smoking uptake were examined in latent growth curve analyses of data from 1,320 youths assessed 5 times during 6th to 9th grade. Initial smoking stage predicted increases in number of friends who smoked, indicating selection; however, initial number of friends who smoked did not predict smoking stage progression, indicating no significant effect of socialization. Associations over time among smoking stage progression, affiliation with friends who smoke, and parenting behaviors were significant, suggesting dynamic, reciprocal relationships. Parental involvement, monitoring, and expectations provided direct protective effects against smoking progression as well as indirect effects, by limiting increases in number of friends who smoke. These results are consistent with the peer selection hypothesis, confirm the powerful association over time of social influences with smoking, and provide the first evidence that parenting behavior may protect against smoking progression by limiting increases in number of friends who smoke.     

Comparative longitudinal structural analyses of the growth and decline of multiple intellectual abilities over the life span.

Latent growth curve techniques and longitudinal data are used to examine predictions from the theory of fluid and crystallized intelligence (Gf-Gc theory; J. L. Horn & R. B. Cattell, 1966, 1967). The data examined are from a sample (N approximately 1,200) measured on the Woodcock-Johnson Psycho-Educational Battery-Revised (WJ-R). The longitudinal structural equation models used are based on latent growth models of age using two-occasion "accelerated" data (e.g., J. J. McArdle & R. Q. Bell, 2000; J. J. McArdle & R. W. Woodcock, 1997). Nonlinear mixed-effects growth models based on a dual exponential rate yield a reasonable fit to all life span cognitive data. These results suggest that most broad cognitive functions fit a generalized curve that rises and falls. Novel multilevel models directly comparing growth curves show that broad fluid reasoning (Gf) and acculturated crystallized knowledge (Gc) have different growth patterns. In all comparisons, any model of cognitive age changes with only a single g factor yields an overly simplistic view of growth and change over age.     

Predicting cognitive control from preschool to late adolescence and young adulthood

In this longitudinal study, the proportion of time preschoolers directed their attention away from rewarding stimuli during a delay-of-gratification task was positively associated with efficiency (greater speed without reduced accuracy) at responding to targets in a go/no-go task more than 10 years later. The overall findings suggest that preschoolers' ability to effectively direct their attention away from tempting aspects of the rewards in a delay-of-gratification task may be a developmental precursor for the ability to perform inhibitory tasks such as the go/no-go task years later. Because performance on the go/no-go task has previously been characterized as involving activation of fronto-striatal regions, the present findings also suggest that performance in the delay-of-gratification task may serve as an early marker of individual differences in the functional integrity of this circuitry.     

Reading practices,reading skills,and cognitive growth in adulthood

Reading is assumed to play an important role in the development of literate persons in that it is consciousness-altering activity. The manner by which reading contributes to development is unclear, however, and has been debated by social scientists for some years. Despite the importance of reading in adult life, only recently have researchers devoted significant attention to what and how well adults read. Less scrutiny has been directed toward understanding what sorts of benefits may be gained from reading in adult life and how reading contributes to adult development. This paper describes adults' reading practices across a variety of social contexts, the types of skills employed in these practices, and how reading may contribute to adult cognitive development. Implications deriving from a better understanding of adult reading practices and skills across the life span are discussed.     

Latent growth curve analysis with dichotomous items: Comparing four approaches

A Monte Carlo study was used to compare four approaches to growth curve analysis of subjects assessed repeatedly with the same set of dichotomous items: A two‐step procedure first estimating latent trait measures using MULTILOG and then using a hierarchical linear model to examine the changing trajectories with the estimated abilities as the outcome variable; a structural equation model using modified weighted least squares (WLSMV) estimation; and two approaches in the framework of multilevel item response models, including a hierarchical generalized linear model using Laplace estimation, and Bayesian analysis using Markov chain Monte Carlo (MCMC). These four methods have similar power in detecting the average linear slope across time. MCMC and Laplace estimates perform relatively better on the bias of the average linear slope and corresponding standard error, as well as the item location parameters. For the variance of the random intercept, and the covariance between the random intercept and slope, all estimates are biased in most conditions. For the random slope variance, only Laplace estimates are unbiased when there are eight time points.     

An experimental analysis of dynamic hypotheses about cognitive abilities and achievement from childhood to early adulthood

This study examined the dynamics of cognitive abilities and academic achievement from childhood to early adulthood. Predictions about time-dependent "coupling" relations between cognition and achievement based on R. B. Cattell's (1971, 1987) investment hypothesis were evaluated using linear dynamic models applied to longitudinal data (N=672). Contrary to Cattell's hypothesis, a first set of findings indicated that fluid and crystallized abilities, as defined by the Woodcock-Johnson Psycho-Educational Battery-Revised (WJ-R; R. W. Woodcock & M. B. Johnson, 1989-1990), were not dynamically coupled with each other over time. A second set of findings provided support for the original predictions and indicated that fluid ability was a leading indicator of changes in achievement measures (i.e., quantitative ability and general academic knowledge). The findings of this study suggest that the dynamics of cognitive abilities and academic achievement follow a more complex pattern than that specified by Cattell's investment hypothesis.     

A coordinated analysis of the associations among personality traits,cognitive decline,and dementia in older adulthood

There are individual differences in the rates of cognitive decline across later adulthood. Personality traits are among the factors that may account for these differences. The current project investigated whether personality traits were associated with trajectories of cognitive decline, and whether the associations were different before and after dementia diagnosis. The data was analyzed using linear mixed effects regression. Across study aims is a focus on replicability and generalizability. Each question was addressed in four independent longitudinal studies (EAS, MAP, ROS, SATSA), then meta-analyzed, providing estimates of replicability. Results indicated that low neuroticism and high openness were associated with total cognitive function. We detected evidence for cognitive decline in all four samples, and openness was associated with decline post dementia diagnosis.     

Missing not at random models for latent growth curve analyses

The past decade has seen a noticeable shift in missing data handling techniques that assume a missing at random (MAR) mechanism, where the propensity for missing data on an outcome is related to other analysis variables. Although MAR is often reasonable, there are situations where this assumption is unlikely to hold, leading to biased parameter estimates. One such example is a longitudinal study of substance use where participants with the highest frequency of use also have the highest likelihood of attrition, even after controlling for other correlates of missingness. There is a large body of literature on missing not at random (MNAR) analysis models for longitudinal data, particularly in the field of biostatistics. Because these methods allow for a relationship between the outcome variable and the propensity for missing data, they require a weaker assumption about the missing data mechanism. This article describes 2 classic MNAR modeling approaches for longitudinal data: the selection model and the pattern mixture model. To date, these models have been slow to migrate to the social sciences, in part because they required complicated custom computer programs. These models are now quite easy to estimate in popular structural equation modeling programs, particularly Mplus. The purpose of this article is to describe these MNAR modeling frameworks and to illustrate their application on a real data set. Despite their potential advantages, MNAR-based analyses are not without problems and also rely on untestable assumptions. This article offers practical advice for implementing and choosing among different longitudinal models.     

Novelty seeking in adulthood: increases accompany decline

Using stereotypes, researchers have predicted that novelty seeking declines in adulthood. Through this cross-sectional study, the authors revealed that only the external sensational type of novelty seeking declined, whereas the internal sensational and internal and external cognitive types remained stable or increased. A population of 233 adults (152 men, 81 women) completed the Novelty Experiencing Scale (P. H. Pearson, 1970). Correlational analyses revealed that older men sought novelty more frequently through cognition than did younger men and that older women were less likely than were younger women to seek novelty through their senses. Multivariate analysis of variance, 2 x 5 (Gender x Age), showed that cognitive novelty seeking increased significantly among participants younger than 50 years of age. Sensational novelty seeking was lower among women older than 40 years and among men older than 50 years. The analyses revealed no significant Gender x Age interactions.     

Observing the preservation and decline of abilities in dementias

The Brief Cognitive Rating Scale facilitated observation of the preservation and decline of abilities due to dementias among 73 female and 52 male residents at nursing homes in a northeastern and southwestern state. They ranged in age from 41 to 102 years (M=78, SD = 10.5). Dementia diagnoses included presenile Alzheimers, senile Alzheimers, Vascular Dementia, Dementia secondary to Huntington's Disease, Dementia due to Pick's Disease, and Korsakoff Dementia secondary to chronic alcoholism. Their ratings on tasks of the scale were submitted to an order analysis procedure to explore the order of decline and preservation of abilities. Results for these nursing home residents show an apparent order: loss singly or concurrently of the abilities of concentration and recent memory, followed by past memory and functioning and self-care that also appeared to be unpredictably lost or preserved singly or concurrently by different individuals, and, finally, by orientation that was preserved in 82% of the subjects.     

Sex-role development in late adolescence and adulthood

The present study investigated associations between age and sex roles in a cross-sectional analysis of people varying in age from late adolescence to middle adulthood. People in the androgynous sex role were older than sex-typed men and women. Cross-sex characteristics tended to be greater among older people, while same-sex characteristics were uncorrelated with age. Sex-role development appears to continue into adulthood, a view more in keeping with a transcendent model than a traditional model of sex-role development.This study was assisted by computer funds from the College of Human Development, The Pennsylvania State University. The authors thank an anonymous reviewer for helpful comments on an earlier version of this article.     

Optimal recall in early and late adulthood

Mäntylä & Nilsson (1983) recently presented a striking empirical phenomenon demonstrating a practically perfect recall of verbal materials encountered at one single trial and without specific instructions to learn the items. The purpose of the study to be presented in this article was to investigate whether older adults are capable of performing at the same high level of recall as younger adults did in the Mäntylä & Nilsson study. Type of instructions and number of retrieval cues were included in the experimental design, in addition to the age factor. Although the results indicated a superior memory performance of younger adults as compared to older adults, the latter group of subjects demonstrated an extremely high level of recall as well. Both age groups showed quite similar recall patterns in the sense that no interaction effects between the age factor and the other independent variables were obtained. The data were discussed relative to qualitatively and quantitatively based explanations of age differences in memory.     

The evolution of paternal identity in late adulthood

The experience of fatherhood in late adulthood has received little attention in the psychoanalytic literature. After a presentation of the literature on fatherhood and a consideration of the developmental tasks of late adulthood in which the experience of fatherhood is embedded, the dynamically charged, developmentally conflicted nature of the relationships between late-life fathers and their children is explored. A basic premise is that the changing nature of these relationships inevitably confronts the elderly patriarch with considerable intra-psychic turmoil, reflection, and conflict that must be engaged and mastered if these most significant relationships are to be maintained and sustained for both generations. Clinical examples illustrate the theoretical points presented.