Stability and change in adult intelligence: 1. Analysis of longitudinal covariance structures

We address two questions of central interest in adult intellectual development: the equivalence of psychometric tests' measurement properties at different ages, and the stability of individual differences in intelligence over time. We performed a series of longitudinal factor analyses using the LISREL program to model longitudinal data from Schaie's Seattle Longitudinal Study. The results indicate complete invariance in the loadings of five subtests of Thurstone's Primary Mental Abilities battery on a general intelligence factor. Individual differences in general intelligence were highly stable over 14-year epochs, with standardized factor correlations averaging about .9 between adjacent 7-year testing intervals. These results indicate that most individuals in this relatively select longitudinal sample maintained their relative ordering in intelligence.     

Stability and change in longitudinal water-level task performance.

Three longitudinal samples of children (N = 481), 8 to 16 years old, were assessed 3 times at yearly intervals on 8 water-level items. The within-child change in task performance over age is viewed as a stochastic process of the child changing or remaining in 1 of 3 latent (strategy) states: (a) bottom-parallel responders, (b) random responders, or (c) accurate responders. A random-effects binomial mixture distribution is used to model performance at each age. Change over age is gauged by a stochastic transition model. Although there was improvement in task performance over age, the more general finding is that strategy stability, not change, is most typical.     

Career maturity: A latent means and covariance structure analysis of Daidalos

A latent means and covariance structure analysis was conducted to assess the construct validity and construct comparability in the measuring of career maturity across boys and girls. The career maturity inventory has been coined Daidalos. The sample consisted of 2,443 high school students recruited from one county in Norway. Of these, 1,132 were males, and 1,311 were females. The mean age of the participants was 17 years of age. Goodness-of-fit statistics provided support for a five-factor first-order model in which the factor loadings, factor covariances and item intercepts were invariant across groups. Additionally, ΔS-B χ² was shown to be non-significant for the testing of invariance of the measurement model. Three significant differences in latent means were detected, with boys scoring higher on negative attitudes toward school or dropout intentions, and girls scoring higher on career uncertainty and need for world-of-work information.     

Stability and change in personality pathology: revelations of three longitudinal studies

Three major longitudinal studies of personality disorder jointly provide new insights into the nature of stability and change in this important domain of psychopathology. This commentary highlights some of the many convergent results, which indicate robust findings that can be considered "established," and also differences in the studies' purposes and methods that permit each study to make unique contributions. One of the most important findings across the studies is that DSM- diagnosed personality disorder is not as stable as the characteristic traits that underlie personality pathology, leading to the insight that DSM personality disorders are hybrids of more acute, "Axis I-like" symptoms that resolve more quickly and longer lasting affective, cognitive, and behavioral personality dysfunctions. Implications for future research are considered.     

Stability and change in work values: A meta-analysis of longitudinal studies

A meta-analysis of longitudinal studies was conducted to investigate stability and change in work values across the life span. Both rank-order stability and mean-level change were investigated using an integrative classification for intrinsic, extrinsic, social and status work values (Ross, Schwartz, & Surkis, 1999). Results of rank-order stability indicated that work values were stable individual differences (ρ = .62). The stability level was lowest during college years (18–22 years old) and highest after entering the workforce (22 years old and later). Work values were more stable than personality traits across all age categories, whereas not as stable as vocational interests during college years and adulthood. Baby Boomers were found to possess a higher level of rank-order stability as compared to Generation X. Mean-level results showed that during college years (18–22 years old), the population as a whole attached more importance to intrinsic values while deemphasizing all the remaining values; during the initial entry of the workforce (22–26 years old), only extrinsic values showed an increase in importance while all the other values decreased; later on after adulthood years (26 years and after), besides the continuous increase of extrinsic values, there was also a dramatic increase in status values. Theoretical and practical implications were discussed.     

Stability and change in generative concern: Evidence from a longitudinal survey

Longitudinal data taken at a ten-year interval from a large, nationally representative sample were used to examine stability and change in generative concern, as measured by a reduced form of the Loyola Generativity Scale (LGS). Rank-order stability over a ten year period was high (r > .6) among those respondents 30 or older at the time of first measurement. Mean scores on the LGS increased for men aged 24–29 and decreased for men and women aged 60–69, but the size of these changes was small. First marriage and childbearing were not associated with an increase in LGS scores. The evidence suggests both life-long stability and a small mid-life peak in generative concern.     

Readiness to change: A longitudinal study of changes in adult identity

It has been suggested in the identity literature that a readiness to change may play a role in identity development beyond adolescence, but an empirical investigation of this relationship had yet to be conducted until now. Therefore, the purpose of the current study was to establish a longitudinal relationship between readiness to change and adult identity development. Participants completed measures of readiness to change and identity at both the beginning and the end of the study. The results revealed a relationship between readiness to change and changes in identity exploration over the study interval, and between readiness to change and changes in identity commitment. The findings are discussed in terms of the currently available literature on identity development in adulthood.     

Stability and change in interests: A longitudinal examination of grades 7 through college

The joint issue of stability and change of interests in adolescence and early adulthood was investigated longitudinally over three years in three different grade cohorts. The patterns of structural stability, mean stability, rank order stability, and profile stability as well as how these patterns were moderated by gender were examined based on three cohorts of grades 7 and 8 (n = 3191), grades 9 and 10 (n = 6818), and grades 11 and 12 (n = 1078) using the Personal Globe Inventory-Short (Tracey, 2010). Results indicated that adherence to the RIASEC circular model was high and stable; there was a lack of appreciable change in interest means; interests were stable; interest crystallization, profile, and pattern were stable. While the results supported late adolescence and early adulthood being a stable period for interests in general, more changes were found among male and younger students. The implication of the current study was discussed along with its limitations and suggestions for future research.     

Emotional intelligence in young and middle adulthood: cross-sectional analysis of latent structure and means

Differentiation of the construct of emotional intelligence was investigated in young and middle-aged adults, on the basis of hypotheses generated from differential emotions theory, discrete emotions functionalist theory, and empirical literature on age-related changes in affective complexity and differentiation of abilities. Both age groups were characterized by the same set of comparably related dimensions. However, midlife adults reported significantly greater use of optimism as a mood-regulation strategy than was reported by young adults. This study considers implications of possible structural continuity in emotional intelligence in conjunction with mean increases in the use of optimism as a strategy for managing affect.     

An incomplete data approach to the analysis of covariance structures

In this paper, linear structural equation models with latent variables are considered. It is shown how many common models arise from incomplete observation of a relatively simple system. Subclasses of models with conditional independence interpretations are also discussed. Using an incomplete data point of view, the relationships between the incomplete and complete data likelihoods, assuming normality, are highlighted. For computing maximum likelihood estimates, the EM algorithm and alternatives are surveyed. For the alternative algorithms, simplified expressions for computing function values and derivatives are given. Likelihood ratio tests based on complete and incomplete data are related, and an example on using their relationship to improve the fit of a model is given.This research forms part of the author's doctoral thesis and was supported by a Commonwealth Postgraduate Research Award. The author also wishes to acknowledge the support of CSIRO during the preparation of this paper and the referees' comments which led to substantial improvements.     

Mechanisms of change in adolescent life satisfaction: A longitudinal analysis

This study explored the psychosocial mechanisms of change associated with differences in levels and linear change of adolescents' global life satisfaction across a 2-year time period. Based on a theoretical model proposed by Evans (1994), this study tested the relations between selected personality (i.e., extraversion and neuroticism) and environmental (stressful life events) variables and global life satisfaction when mediated by internalizing and externalizing problems. The results suggested support for internalizing problems as a mediator of the relationship of personality and environmental variables with life satisfaction. Pathways mediated by internalizing problems significantly predicted levels and linear change of life satisfaction across a 2-year time span. Furthermore, pathways mediated by externalizing problems significantly predicted the level but not the linear change of life satisfaction. Thus, behavior problems and their antecedents appear to relate significantly to adolescents' perceptions of their quality of life. Implications for adolescent mental health promotion were discussed.     

Stability and change of basic personal values in early adulthood: An 8-year longitudinal study

We examined four types of stability and change in values during young adulthood. 270 respondents (aged 20–28, 54% female) completed the Portrait Values Questionnaire at three time points, separated by 4 years. Rank-order stability coefficients of the 10 values averaged 0.69 (T1-T2) and 0.77 (T2-T3). The mean importance of conservation, self-transcendence, and power values increased over time, the mean importance of achievement values decreased, and openness to change values remained stable. For 75% of respondents, the correlations of the within-person value hierarchies exceeded 0.45 from T1 to T2 and 0.61 from T2 to T3. Correlations among individual change scores for the 10 values formed coherent patterns of value change that mirror the circular structure of Schwartz’s theory.     

Stability and change in interests: A longitudinal study of adolescents from grades 8 through 12

The pattern of RIASEC interests and academic skills were assessed longitudinally from a large-scale national database at three time points: eight grade, 10th grade, and 12th grade. Validation and cross-validation samples of 1000 males and 1000 females in each set were used to test the pattern of these scores over time relative to mean changes, stability, crystallization, and interest-career choice congruence as well as how these patterns were moderated by gender. Results indicate that the pattern of interests was fairly stable in grades 8-12 for males and females. Interests were also found to become more crystallized over time; however interest-career choice congruence evidenced an inverted V pattern. With further examination, student interests became less people based and their career choices more people based in grade 12. The results support the importance of grade 12 as a time of focus for research and intervention, and for continuing investigation of gender differences in adolescent career and academic development.     

Stability analysis in K‐means clustering

This paper develops a new procedure, called stability analysis, for K‐means clustering. Instead of ignoring local optima and only considering the best solution found, this procedure takes advantage of additional information from a K‐means cluster analysis. The information from the locally optimal solutions is collected in an object by object co‐occurrence matrix. The co‐occurrence matrix is clustered and subsequently reordered by a steepest ascent quadratic assignment procedure to aid visual interpretation of the multidimensional cluster structure. Subsequently, measures are developed to determine the overall structure of a data set, the number of clusters and the multidimensional relationships between the clusters.     

Improper solutions in the analysis of covariance structures: Their interpretability and a comparison of alternate respecifications

A Monte Carlo approach was employed to investigate the interpretability of improper solutions caused by sampling error in maximum likelihood confirmatory factor analysis. Four models were studied with two sample sizes. Of the overall goodness-of-fit indices provided by the LISREL VI program significant differences between improper and proper solutions were found only for the root mean square residual. As expected, indicators of the factor on which the negative uniqueness estimate occurred had biased loadings, and the correlations of its factor with other factors were also biased. In contrast, the loadings of indicators on other factors and those factor intercorrelations did not have any bias of practical significance. For initial solutions with one negative uniqueness estimate, three respecifications were studied: Fix the uniqueness at .00, fix it at .20, or constrain the domain of the solution to be proper. For alternate, respecified solutions that were converged and proper, the constrained solutions and uniqueness fixed at .00 solutions were equivalent. The mean goodness-of-fit and pattern coefficient values for the original improper solutions were not meaningfully different from those obtained under the constrained and uniqueness fixed at .00 respecifications.This investigation was supported in part by a grant from the Baylor University Research Committee (#018-F83-URC). The authors gratefully acknowledge the comments and suggestions of Claes Fornell and Roger E. Kirk, and the assistance of Timothy J. Vance with the analysis.     

Stability and change in feelings of loneliness: A two-year prospective longitudinal study of advanced alcohol abusers

In order to study the changing nature of loneliness in a prospective design, 78 alcoholics were examined twice with an interval of two years. Change scores in loneliness were correlated with change scores in social network, psychological well-being, life-satisfaction, activities, adaptation to one's work and non-work situation, psychiatric symptoms and alcohol consumption. In addition, a step-wise multiple regression analysis with loneliness change as the dependent variable was performed. Change in loneliness was accompanied by changes in well-being (especially indolence, self-esteem and perceived treatment from others), mood-related psychiatric variables and satisfaction with autonomy and life as a whole. However, other variables, like satisfaction with one's social network and a number of non-cyclic psychiatric disorders, did not change along with loneliness, despite stable cross-sectional links. The discrepancy between the cross-sectional and the longitudinal correlation patterns may be indicative of different forms of loneliness in regard to temporal stability.