Comparative fit indexes in structural models

Normed and nonnormed fit indexes are frequently used as adjuncts to chi-square statistics for evaluating the fit of a structural model. A drawback of existing indexes is that they estimate no known population parameters. A new coefficient is proposed to summarize the relative reduction in the noncentrality parameters of two nested models. Two estimators of the coefficient yield new normed (CFI) and nonnormed (FI) fit indexes. CFI avoids the underestimation of fit often noted in small samples for Bentler and Bonett's (1980) normed fit index (NFI). FI is a linear function of Bentler and Bonett's non-normed fit index (NNFI) that avoids the extreme underestimation and overestimation often found in NNFI. Asymptotically, CFI, FI, NFI, and a new index developed by Bollen are equivalent measures of comparative fit, whereas NNFI measures relative fit by comparing noncentrality per degree of freedom. All of the indexes are generalized to permit use of Wald and Lagrange multiplier statistics. An example illustrates the behavior of these indexes under conditions of correct specification and misspecification. The new fit indexes perform very well at all sample sizes.

Association of anxiety-related traits with a polymorphism in the serotonin transporter gene regulatory region

Transporter-facilitated uptake of serotonin (5-hydroxytryptamine or 5-HT) has been implicated in anxiety in humans and animal models and is the site of action of widely used uptake-inhibiting antidepressant and antianxiety drugs. Human 5-HT transporter (5-HTT) gene transcription is modulated by a common polymorphism in its upstream regulatory region. The short variant of the polymorphism reduces the transcriptional efficiency of the 5-HTT gene promoter, resulting in decreased 5-HTT expression and 5-HT uptake in lymphoblasts. Association studies in two independent samples totaling 505 individuals revealed that the 5-HTT polymorphism accounts for 3 to 4 percent of total variation and 7 to 9 percent of inherited variance in anxiety-related personality traits in individuals as well as sibships.

A prospective study of depression and posttraumatic stress symptoms after a natural disaster: the 1989 Loma Prieta Earthquake

Measures of emotional health and styles of responding to negative moods were obtained for 137 students 14 days before the Loma Prieta earthquake. A follow-up was done 10 days again 7 weeks after the earthquake to test predictions about which of the students would show the most enduring symptoms of depression and posttraumatic stress. Regression analysis showed that students who, before the earthquake, already had elevated levels of depression and stress symptoms and a ruminative style of responding to their symptoms had more depression and stress symptoms for both follow-ups. Students who were exposed to more dangerous or difficult circumstances because of the earthquake also had elevated symptom levels 10 days after the earthquake. Similarly, students who, during the 10 days after the earthquake, had more ruminations about the earthquake were still more likely to have high levels of depressive and stress symptoms 7 weeks after the earthquake.

Health complaints, stress, and distress: exploring the central role of negative affectivity

Most current models in health psychology assume that stress adversely affects physical health. We re-examined this assumption by reviewing extensive data from the literature and from six samples of our own, in which we collected measures of personality, health and fitness, stress, and current emotional functioning. Results indicate that self-report health measures reflect a pervasive mood disposition of negative affectivity (NA); self-report stress scales also contain a substantial NA component. However, although NA is correlated with health compliant scales, it is not strongly or consistently related to actual, long-term health status, and thus will act as a general nuisance factor in health research. Because self-report measures of stress and health both contain a significant NA component, correlations between such measures likely overestimate the true association between stress and health. Results demonstrate the importance of including different types of health measures in health psychology research.

The structure of phenotypic personality traits

This personal historical article traces the development of the Big-Five factor structure, whose growing acceptance by personality researchers has profoundly influenced the scientific study of individual differences. The roots of this taxonomy lie in the lexical hypothesis and the insights of Sir Francis Galton, the prescience of L. L. Thurstone, the legacy of Raymond B. Cattell, and the seminal analyses of Tupes and Christal. Paradoxically, the present popularity of this model owes much to its many critics, each of whom tried to replace it, but failed. In reaction, there have been a number of attempts to assimilate other models into the five-factor structure. Lately, some practical implications of the emerging consensus can be seen in such contexts as personnel selection and classification.

The rank-order consistency of personality traits from childhood to old age: a quantitative review of longitudinal studies

The present study used meta-analytic techniques to test whether trait consistency maximizes and stabilizes at a specific period in the life course. From 152 longitudinal studies, 3,217 test-retest correlation coefficients were compiled. Meta-analytic estimates of mean population test-retest correlation coefficients showed that trait consistency increased from .31 in childhood to .54 during the college years, to .64 at age 30, and then reached a plateau around .74 between ages 50 and 70 when time interval was held constant at 6.7 years. Analysis of moderators of consistency showed that the longitudinal time interval had a negative relation to trait consistency and that temperament dimensions were less consistent than adult personality traits.

Perfectionism in the self and social contexts: Conceptualization, assessment, and association with psychopathology

This article attempted to demonstrate that the perfectionism construct is multidimensional, comprising both personal and social components, and that these components contribute to severe levels of psychopathology. We describe three dimensions of perfectionism: self-oriented perfectionism, other-oriented perfectionism, and socially prescribed perfectionism. Four studies confirm the multidimensionality of the construct and show that these dimensions can be assessed in a reliable and valid manner. Finally, a study with 77 psychiatric patients shows that self-oriented, other-oriented, and socially prescribed perfectionism relate differentially to indices of personality disorders and other psychological maladjustment. A multidimensional approach to the study of perfectionism is warranted, particularly in terms of the association between perfectionism and maladjustment.

The process of smoking cessation: An analysis of precontemplation, contemplation, and preparation stages of change

Traditionally smoking cessation studies use smoker and nonsmoker categories almost exclusively to represent individuals quitting smoking. This study tested the transtheoretical model of change that posits a series of stages through which smokers move as they successfully change the smoking habit. Subjects in precontemplation (n = 166), contemplation (n = 794), and preparation (n = 506) stages of change were compared on smoking history, 10 processes of change, pretest self-efficacy, and decisional balance, as well as 1-month and 6-month cessation activity. Results strongly support the stages of change model. All groups were similar on smoking history but differed dramatically on current cessation activity. Stage differences predicted attempts to quit smoking and cessation success at 1- and 6-month follow-up. Implications for recruitment, intervention, and research are discussed.

Implicit measures in social cognition. research: their meaning and use

Behavioral scientists have long sought measures of important psychological constructs that avoid response biases and other problems associated with direct reports. Recently, a large number of such indirect, or "implicit," measures have emerged. We review research that has utilized these measures across several domains, including attitudes, self-esteem, and stereotypes, and discuss their predictive validity, their interrelations, and the mechanisms presumably underlying their operation. Special attention is devoted to various priming measures and the Implicit Association Test, largely due to their prevalence in the literature. We also attempt to clarify several unresolved theoretical and empirical issues concerning implicit measures, including the nature of the underlying constructs they purport to measure, the conditions under which they are most likely to relate to explicit measures, the kinds of behavior each measure is likely to predict, their sensitivity to context, and the construct's potential for change.

Appraisal, coping, health status, and psychological symptoms

In this study we examined the relation between personality factors (mastery and interpersonal trust), primary appraisal (the stakes a person has in a stressful encounter), secondary appraisal (options for coping), eight forms of problem- and emotion-focused coping, and somatic health status and psychological symptoms in a sample of 150 community-residing adults. Appraisal and coping processes should be characterized by a moderate degree of stability across stressful encounters for them to have an effect on somatic health status and psychological symptoms. These processes were assessed in five different stressful situations that subjects experienced in their day-to-day lives. Certain processes (e.g., secondary appraisal) were highly variable, whereas others (e.g., emotion-focused forms of coping) were moderately stable. We entered mastery and interpersonal trust, and primary appraisal and coping variables (aggregated over five occasions), into regression analyses of somatic health status and psychological symptoms. The variables did not explain a significant amount of the variance in somatic health status, but they did explain a significant amount of the variance in psychological symptoms. The pattern of relations indicated that certain variables were positively associated and others negatively associated with symptoms.

Personality similarity in twins reared apart and together

We administered the Multidimensional Personality Questionnaire (MPQ) to 217 monozygotic and 114 dizygotic reared-together adult twin pairs and 44 monozygotic and 27 dizygotic reared-apart adult twin pairs. A four-parameter biometric model (incorporating genetic, additive versus nonadditive, shared family-environment, and unshared environment components) and five reduced models were fitted through maximum-likelihood techniques to data obtained with the 11 primary MPQ scales and its 3 higher order scales. Solely environmental models did not fit any of the scales. Although the other reduced models, including the simple additive model, did fit many of the scales, only the full model provided a satisfactory fit for all scales. Heritabilities estimated by the full model ranged from .39 to .58. Consistent with previous reports, but contrary to widely held beliefs, the overall contribution of a common family-environment component was small and negligible for all but 2 of the 14 personality measures. Evidence of significant nonadditive genetic effects, possibly emergenic (epistatic) in nature, was obtained for 3 of the measures.

Psychotomimesis mediated by kappa opiate receptors

The kappa opioid agonists are analgesics that seem to be free of undesired morphine-like effects. Their dysphoric actions observed with the kappa agonist cyclazocine are thought to be mediated by an action at sigma-phencyclidine receptors. The benzomorphan kappa agonist MR 2033 is inactive at sigma-phencyclidine receptors. In male subjects, the opiate-active (-)-isomer, but not the (+)-isomer, elicited dose-dependent dysphoric and psychotomimetic effects that were antagonized by naloxone. Thus, kappa opiate receptors seem to mediate psychotomimetic effects. In view of the euphorigenic properties of mu agonists, our results imply the existence of opposed opioid systems affecting emotional and perceptual experiences.

Measures of impulsivity in cigarette smokers and non-smokers

RATIONALE

Drug users are thought to be more "impulsive" than non-users.

OBJECTIVES

This study examined whether regular smokers are more impulsive than never smokers using personality and behavioral measures of impulsivity.

METHODS

Twenty regular smokers (>/=15 cigarettes/day) and 20 never smokers were recruited. Participants completed five personality questionnaires to assess impulsivity: Adjective Checklist, Barratt's Impulsivity Scale, the Tridimensional Personality Questionnaire, Eysenck's Personality Questionnaire, and the Sensation-Seeking Scale. Participants also performed three behavioral choice tasks designed to assess impulsivity. In the delay task, participants chose between small, immediate and large, delayed monetary rewards. Impulsivity was defined as a relative preference for the small, immediate alternative. In the probability task, participants chose between small, certain and large, uncertain monetary rewards. Impulsivity was defined as a relative preference for the large but more risky alternative. In the work task, participants chose between small monetary rewards obtained by performing a negligible amount of work and a larger amount of money requiring more work. Impulsivity was defined as a relative preference for the smaller, easier alternative.

RESULTS

On the personality questionnaires, smokers had statistically higher impulsivity scores on most scales. On the behavioral choice tasks, smokers chose small, immediate money over large, delayed money more frequently, signifying greater levels of impulsivity. There were no differences between the groups' choices on the other tasks. Correlations between questionnaire and task data were small, as were correlations between data from each task.

CONCLUSIONS

Together, these results indicate that the smokers were more impulsive than never smokers.

Functional and dysfunctional impulsivity: Personality and cognitive correlates

The 3 studies reported here were designed to clarify the nature of the personality trait of impulsivity. Two types of impulsivity were distinguished. Dysfunctional impulsivity is the tendency to act with less forethought than most people of equal ability when this tendency is a source of difficulty; most previous work on impulsivity appears to have focused on this trait. Functional impulsivity, in contrast, is the tendency to act with relatively little forethought when such a style is optimal. The present work indicates that these two tendencies are not highly correlated and that they bear different relations both to other personality traits and to the manner in which certain basic cognitive processes are executed.

Neuroticism, somatic complaints, and disease: is the bark worse than the bite?

Perhaps because negative emotions are frequently expressed in physiological reactions, psychosomatic theories have often identified Neuroticism and its component traits (including anxiety, anger, and depression) as causal influences on the development of disease. These views are apparently supported by correlations between physical symptom reports and measures of Neuroticism in males. Data from 347 adult women in the Baltimore Longitudinal Study of Aging replicate this finding for total physical complaints and for most body systems. However, analyses of mortality in the literature and in the present article show no influence of Neuroticism, suggesting that symptom reporting may be biased by Neuroticism-related styles of perceiving and reporting physiological experiences. Researchers in this area are urged to employ objective measures of medical status, and to be alert to possible biases of self-selection and selective perception in interpreting associations between Neuroticism and disease.

Impulsive and self-control choices in opioid-dependent patients and non-drug-using control participants: drug and monetary rewards

Delay discounting was investigated in opioid-dependent and non-drug-using control participants. The latter participants were matched to the former on age, gender, education, and IQ. Participants in both groups chose between hypothetical monetary rewards available either immediately or after a delay. Delayed rewards were $1,000, and the immediate-reward amount was adjusted until choices reflected indifference. This procedure was repeated at each of 7 delays (1 week to 25 years). Opioid-dependent participants were given a second series of choices between immediate and delayed heroin, using the same procedures (i.e., the amount of delayed heroin was that which could be purchased with $1,000). Opioid-dependent participants discounted delayed monetary rewards significantly more than did non-drug-using participants. Furthermore opioid-dependent participants discounted delayed heroin significantly more than delayed money.

Interpersonal and intrapsychic adaptiveness of trait self-enhancement: a mixed blessing?

Reactions to trait self-enhancers were investigated in 2 longitudinal studies of person perception in discussion groups. Groups of 4-6 participants met 7 times for 20 min. After Meetings 1 and 7, group members rated their perceptions of one another. In Study 1, trait self-enhancement was indexed by measures of narcissism and self-deceptive enhancement. At the first meeting, self-enhancers made positive impressions. They were seen as agreeable, well adjusted, and competent. After 7 weeks, however, they were rated negatively and gave self-evaluations discrepant with peer evaluations they received. In Study 2, an independent sample of observers (close acquaintances) enabled a pretest index of discrepancy self-enhancement: It predicted the same deteriorating pattern of interpersonal perceptions as the other three trait measures. Nonetheless, all self-enhancement measures correlated positively with self-esteem.

Supportive interactions, negative interactions, and depressed mood

Research on the association between social relationships and emotional functioning has emphasized the health-promoting effects of social support. Yet there is reason to believe that the absence of negative social interactions may be more important for mental health than the presence of supportive interactions. In this investigation we clarify important characteristics concerning the source, the recipient, and the combined influence of support and negativity. Data are presented regarding supportive and negative interactions with spouse, relatives, and friends; regression analyses suggest that negative interactions are more predictive of depressed mood than supportive interactions (specifically with spouse and friends). We also document several specifications suggesting directions for future research on the special importance of interactions in intimate relationships and the synergistic effects of situations in which supportive and negative interactions both occur.

Personality and job performance: the Big Five revisited

Prior meta-analyses investigating the relation between the Big 5 personality dimensions and job performance have all contained a threat to construct validity, in that much of the data included within these analyses was not derived from actual Big 5 measures. In addition, these reviews did not address the relations between the Big 5 and contextual performance. Therefore, the present study sought to provide a meta-analytic estimate of the criterion-related validity of explicit Big 5 measures for predicting job performance and contextual performance. The results for job performance closely paralleled 2 of the previous meta-analyses, whereas analyses with contextual performance showed more complex relations among the Big 5 and performance. A more critical interpretation of the Big 5-performance relationship is presented, and suggestions for future research aimed at enhancing the validity of personality predictors are provided.

The Cook-Medley hostility scale: item content and ability to predict survival

Previous studies have identified the MMPI-based Cook and Medley hostility scale (Ho) as a predictor of health outcomes. To achieve a better understanding of the construct measured by this scale, Ho items were classified on an a priori basis. Six subsets were identified: Cynicism, Hostile Attributions, Hostile Affect, Aggressive Responding, Social Avoidance, and Other. Study 1 examined the correlations of these subsets with scales of the NEO Personality Inventory in two samples of undergraduates. Good convergent and discriminant validity were demonstrated, but there was some evidence that items in the Social Avoidance and Other categories reflect constructs other than hostility. Study 2 examined the ability of the Ho scale and the item subsets to predict the 1985 survival of 118 lawyers who had completed the MMPI in 1956 and 1957. As in previous studies, those with high scores had poorer survival (chi 2 = 6.37, p = 0.012). Unlike previous studies, the relation between Ho scores and survival was linear. Cynicism, Hostile Affect, and Aggressive Responding subsets were related to survival, whereas the other subsets were not. The sum of the three predictive subsets, with a chi 2 of 9.45 (p = 0.002), was a better predictor than the full Ho scale, suggesting that it may be possible to refine the scale and achieve an even more effective measure of those aspects of hostility that are deleterious to health.