Within-trait heterogeneity in age group differences in personality domains and facets: implications for the development and coherence of personality traits

Are Older Adults More Prosocial Than Younger Adults? A Systematic Review and Meta-Analysis

BACKGROUND AND OBJECTIVES

Prosociality refers to voluntary behaviors that intend to benefit others. Most of the existing literature suggests that older adults tend to act more prosocially compared to younger adults, whereas some studies show that older adults might not be that prosocial under certain conditions. The current study aimed to summarize the mixed findings and quantify the age difference in prosociality by conducting a qualitative systematic review and a quantitative meta-analysis.

RESEARCH DESIGN AND METHODS

Literature search was conducted based on 5 databases. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were followed and this review was registered at PROSPERO (CRD42022333373).

RESULTS

Based on the qualitative synthesis of 51 studies, older adults (n = 109,911) were more prosocial than younger adults (n = 68,501). The meta-analysis of 46 studies further supported this age effect (Hedges' g = 0.31, 95% confidence interval [0.24, 0.37]), and this age effect might be moderated by the types of prosociality. We discovered a moderate age effect in sharing (Hedges' g = 0.53), but a nonsignificant age effect in helping (Hedges' g = 0.11), comforting (Hedges' g = -0.20), or mixed prosociality (Hedges' g = 0.15). Additionally, the age effect was only significant when older adults had higher socioeconomic status than younger adults.

DISCUSSION AND IMPLICATIONS

Future research should develop more comprehensive measures of prosociality, examine more variables that influence aging and prosociality, and investigate the neural mechanism(s) of prosociality to achieve a thorough understanding of the age difference in prosociality.

Social expectations as a possible mechanism for adult personality change: Limited empirical evidence for the social investment principle

OBJECTIVE

Personality traits change in both mean levels and variance across the life span but the mechanisms underlying these developmental trends remain unclear. Social Investment Principle (SIP) suggests that social expectations drive personality changes in adulthood. Accordingly, we tested whether differences between personality traits in social expectations for them can explain their different change trajectories in young adulthood.

METHODS

A pool of 257 personality items was used to measure personality traits' means and variances (N = 1096), and levels expected by friends, partners and bosses/supervisors (N = 121).

RESULTS

Raters were consistent in their expectations for how young adults should think, feel and behave. Traits under stronger expectations had higher mean levels and lower variances than traits under lower expectations; trait means and variances increased with age, but inconsistently with the SIP, these increases were unrelated to the traits' expected levels.

CONCLUSION

Our results are only partially consistent with the SIP.

Social expectations and abilities to meet them as possible mechanisms of youth personality development

OBJECTIVE

Personality traits change from childhood through late-adolescence, however the effects of social expectations and self-regulatory efforts remain unknown. This study aims to explore mechanisms underlying personality development by assessing mean levels personality traits from childhood to late-adolescence.

METHOD

We used Common-Language California Child Q-Set to measure youths' (N=11,000) mean personality trait levels; social expectations for these traits as perceived by parents (N=47), teachers (N=42) and students (N=120); and self-regulatory efforts required for achieving the desired levels in these traits as perceived by parents (N=27), teachers (N=26) and students (N=54).

RESULTS

Expectations for youths' traits were consistent, regardless of raters' or youths' age. In our unique between-trait study design, traits' mean levels were positively associated with expectations for them, but age differences minimally tracked these expectations. Traits' required self-regulatory efforts were not associated with their developmental trends.

CONCLUSIONS

Results were only partially consistent with existing developmental theories of personality development.

Facet-level changes in mothers’ neuroticism and extraversion from early pregnancy to 6 months post-partum

Becoming a parent could be expected to affect personality development, but the existing results on parenthood-personality change connection are mixed. The present study investigated 2445 primi- and multiparous mothers’ facet- and domain-level changes in Neuroticism and Extraversion from early pregnancy to 6 months post-partum, using latent difference score models. The results showed that Excitability and the affective facets of Neuroticism decreased, and the Neuroticism facets Impulsivity and Self-Consciousness increased during the follow-up. Furthermore, mother-perceived child difficult temperament attenuated desirable personality change and amplified the increases in Impulsivity. The results suggested that considering facet-level changes in personality development across significant life events is informative, and that mother-perceived child temperament may represent an important moderator of short-term personality change across the transition to parenthood.

Interindividual age differences in personality structure

Most investigations in the structure of personality traits do not adequately address age; instead, they presuppose a constant structure across the lifespan. Further, few studies look at the structure of personality traits a-theoretically, often neglecting to examine the relationship among indicators within a trait (convergence) and across traits (divergence). Using a network approach, the present study examines (1) age differences in divergence and convergence, (2) the similarity between the Big Five and network structures, and (3) the consistency of network structure across age groups in a large, cross-sectional sample. Results indicate that convergence shows early gains in adolescence with few differences across the lifespan, while divergence mostly weakens across adulthood. The result of these age-related differences is that Big Five indicators only parallel the Big Five structure among young but not older adults. The structure of young adults tends to be quite similar while the network structures of older adults appear to greatly differ from one another. These results suggest that older adults have a different structure of personality than younger adults and suggest that future research should not assume consistency in personality structure across the lifespan.

That Takes the BISCUIT

Abstract. The predictive accuracy of personality-criterion regression models may be improved with statistical learning (SL) techniques. This study introduced a novel SL technique, BISCUIT (Best Items Scale that is Cross-validated, Unit-weighted, Informative, and Transparent). The predictive accuracy and parsimony of BISCUIT were compared with three established SL techniques (the lasso, elastic net, and random forest) and regression using two sets of scales, for five criteria, across five levels of data missingness. BISCUIT’s predictive accuracy was competitive with other SL techniques at higher levels of data missingness. BISCUIT most frequently produced the most parsimonious SL model. In terms of predictive accuracy, the elastic net and lasso dominated other techniques in the complete data condition and in conditions with up to 50% data missingness. Regression using 27 narrow traits was an intermediate choice for predictive accuracy. For most criteria and levels of data missingness, regression using the Big Five had the worst predictive accuracy. Overall, loss in predictive accuracy due to data missingness was modest, even at 90% data missingness. Findings suggest that personality researchers should consider incorporating planned data missingness and SL techniques into their designs and analyses.

WAIS-III measurement invariance: Data from Estonian standardization

OBJECTIVE

A prerequisite of any psychological instrument used to compare individuals from different groups is measurement invariance (MI). It indicates that the test measures the same psychological constructs regardless of the particular grouping variable of the test-taker. Our purpose was to evaluate the MI across sex, age groups and educational levels in the recently adapted Estonian version of the Wechsler Adult Intelligence Scale - Third Edition (WAIS-III).

METHOD

We analysed the Estonian standardization sample of WAIS-III (N = 770) with confirmatory factor analysis (CFA) to establish the best baseline factor model for further analysis. Multi-group confirmatory factor analysis (MG-CFA) was applied to evaluate MI of the test and, granted this, mean differences across sex, age groups and educational levels.

RESULTS

CFA supported the four-factor model. The test demonstrated partial MI across sexes; latent mean comparisons showed that men had a significantly higher mean score on the Perceptual Organization factor. Partial MI also held across age groups and, as expected, older groups had significantly lower means than younger age groups. The analyses across the educational levels failed to prove the MI as the metric invariance was not tenable.

DISCUSSION

The results of this study provide evidence that the structural model underlying the Estonian adaption of WAIS-III is partially invariant across sex and age groups, hence the test functions same manner across these groups. Estonian WAIS-III was not invariant across the educational levels, which may indicate that the measure has a different structure or meaning to different educational groups.

Traits and Adaptations: A Theoretical Examination and New Empirical Evidence

We investigated the distinction between traits (also labelled basic tendencies or dispositions) and (characteristic) adaptations, two related features of the personality system postulated to influence how personality manifests throughout the lifespan. Traits are alleged to be universal, causal, and enduring entities that exist across cultures and through evolutionary time, whereas learned adaptations are acquired through sustained interaction with cultural, physical, and social environments. Although this distinction is central to several personality theories, they provide few measurable criteria to distinguish between traits and adaptations. Moreover, little research has endeavoured to operationalize it, let alone test it empirically. Drawing on insights from four frameworks—the Five–Factor Theory, Cybernetic Big Five Theory, Disposition–Adaptation–Environment Model, and New Big Five—we attempted to investigate the distinction both theoretically and empirically. Using various experimental rating conditions, we first scored 240 questionnaire items in their degrees of definitionally reflecting traits and/or adaptations. Next, we correlated these definitional ratings with the items’ estimates of rank–order stability, consensual validity, and heritability—criteria often associated with personality traits. We found some evidence that items rated as more trait–like and less adaptation–like correspond to higher cross–rater agreement and stability but not heritability. These associations survived controlling for items’ retest reliability, social desirability, and variance. The theoretical and empirical implications of these findings are discussed. © 2020 European Association of Personality Psychology

Do Self-Reports and Informant-Ratings Measure the Same Personality Constructs?

Abstract. Personality researchers often supplement or substitute self-reports with ratings from knowledgeable informants, at least implicitly assuming that the same constructs are being measured regardless of the source of ratings. However, measurement invariance (MI) of personality constructs across these rating types has rarely been empirically tested. Here, this was done for the Five-Factor Model domains and their 30 facets ( N = 3,253). All facets and all domains but Agreeableness met the level of invariance (metric MI) required for comparing the relative standings of individuals across self-reports and informant-ratings, which is what researchers mostly do. However, ten facets and the Agreeableness domain failed to achieve the level of invariance (scalar MI) recommended when comparing mean scores. In conclusion, self-reports and informant-ratings appear to measure similar constructs for most research purposes.

Kids becoming less alike: A behavioral genetic analysis of developmental increases in personality variance from childhood to adolescence

Recent work in personality development has indicated that the magnitude of individual differences in personality increases over child development. Do such patterns reflect the differentiation of individuals by genotype, an increasing influence of environmental factors, or some (interactive) combination of the two? Using a population-based sample of over 2,500 twins and multiples from the Texas Twin Project, we estimated age trends in the variances in self- and parent-reported measures of the Big Five personality traits between Ages 8 and 18 years. We then estimated age trends in the genetic and environmental components of variance in each measure. Individual differences in personality increased in magnitude from childhood through mid-adolescence. This pattern emerged using both children's self-reports and ratings provided by their parents, and was primarily attributable to increases in the magnitude of genetic influences. Most of the increasing genetic variance appeared nonadditive, pointing to the possibility that developmental processes tend to make genetically similar individuals disproportionately more alike in their personality traits over time. These findings could reflect increasing or accumulating effects of trait-by-trait interactions; person-by-environment transactions, whereby genetically similar people are disproportionally likely to experience similar environments; the activation of dominant genes across developmental transitions (e.g., puberty); or some combination of these three processes, among other factors. Theories of personality development will need to accommodate these descriptive findings, and longitudinal, genetically informed designs are needed to test some of the specific hypotheses springing from this study. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Personality Across the Life Span

Trait stability and maturation are fundamental principles of contemporary personality psychology and have been shown to hold across many cultures. However, it has proven difficult to move beyond these general findings to a detailed account of trait development. There are pervasive and unexplained inconsistencies across studies that may be due to ( a) insufficient attention to measurement error, ( b) subtle but age-sensitive differences in alternative measures of the same trait, or ( c) different perspectives reflected in self-reports and observer ratings. Multiscale, multimethod-and ideally multinational-studies are needed. Several hypotheses have been proposed to account for trait stability and change, but supporting evidence is currently weak or indirect; trait development is a fertile if sometimes frustrating field for theory and research. Beyond traits, there are approaches to personality development that are of interest to students of adult development, and these may be fruitfully addressed from a trait perspective.

Personality characteristics below facets: A replication and meta-analysis of cross-rater agreement, rank-order stability, heritability, and utility of personality nuances

Mõttus and colleagues (2017) reported evidence that the unique variance in specific personality characteristics captured by single descriptive items often displayed trait-like properties of cross-rater agreement, rank-order stability, and heritability. They suggested that the personality hierarchy should be extended below facets to incorporate these specific characteristics, called personality nuances. The present study attempted to replicate these findings, employing data from 6,287 individuals from 6 countries (Australia, Canada, Czech Republic, Denmark, Japan, and United States). The same personality measure-240-item Revised NEO Personality Inventory-and statistical procedures were used. The present findings closely replicated the original results. When the original and current results were meta-analyzed, the unique variance of nearly all items (i.e., items' scores residualized for all broader personality traits) showed statistically significant cross-rater agreement (median = .12) and rank-order stability over an average of 12 years (median = .24), and the unique variance of the majority of items had a significant heritable component (median = .14). These 3 item properties were intercorrelated, suggesting that items systematically differed in the degree of reflecting valid unique variance. Also, associations of items' unique variance with age, gender, and body mass index (BMI) replicated across samples and tracked with the original findings. Moreover, associations between item residuals and BMI obtained from one group of people allowed for a significant incremental prediction of BMI in an independent sample. Overall, these findings reinforce the hypotheses that nuances constitute the building blocks of the personality trait hierarchy, their properties are robust and they can be useful. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Role of personality traits in reporting the development of adverse drug reactions: a prospective cohort study of the Estonian general population

OBJECTIVE

To examine the role of the Five Factor Model (FFM) personality traits in reporting the development of adverse drug reactions (ADRs) when controlling for sociodemographic variables and health status.

DESIGN

Prospective cohort study.

SETTING

The Estonian Biobank of the Estonian Genome Centre, University of Tartu.

PARTICIPANTS

814 women and 543 men (mean age=47.9 years; SD=15.2) who after the initial enrolment in the Estonian Biobank were re-contacted for follow-up purposes about 5.3 years after the enrolment and for whom both self- and informant-reported personality data were available.

MAIN OUTCOME MEASURE

Participants who did not report having any ADRs at baseline but who reported ADRs at the follow-up about 5.3 years later versus participants who did not report any ADRs at either time point. The reports of developing ADRs were predicted from the FFM personality traits after statistically controlling for sociodemographic variables (age, gender and education), baseline indicators of health status (number of diagnoses and medicines taken, body mass index and blood pressure), and the change in health status between the two measurements.

RESULTS

The results of a hierarchical binary logistic regression analysis showed that participants who reported the development of ADRs between the two measurements had higher levels of conscientiousness, were more likely to be women, were taking more medicines at baseline and had a higher increase in the number of medicines taken during the study period than participants who did not report any ADRs at either time point (all p values <0.05). Higher neuroticism (p=0.067) and a higher number of diagnosed diseases at baseline (p=0.053) also made marginal contributions to predicting the development of ADRs.

CONCLUSIONS

This study shows for the first time that higher levels of conscientiousness and neuroticism are associated with reporting the development of ADRs.

A Five-Factor Theory Perspective on Causal Analysis

Five-Factor Theory (FFT) provides a broad but largely blank template for causal personality research. Within FFT, there are three major categories of questions: (1) How do biological structures and functions lead to trait levels? (2) how do traits and the environment give rise to acquired psychological institutions? and (3) how do personality characteristics interact with specific situations to determine behaviors and reactions? Both practical and ethical issues complicate the search for the causes of trait change. Causal explanations of the development of characteristic adaptations are likely to be incomplete, because there are many different ways in which the same adaptation may be acquired. Studies of the determinants of behavior are usually left to social, educational, or clinical psychologists-although personality psychologists may make distinctive contributions by emphasizing the role of the individual in selecting and creating situations. A causal understanding of the functioning of the personality system is possible through the integration of many lines of evidence, but it is likely to take a very long time. In the meanwhile, personality psychologists may fruitfully pursue the identification of practical causes by which individuals with a given set of traits can optimize their adaptation. If we require truth in any strict sense, we must confine ourselves to one entire state of the world. This will be the cause, and the next entire state will be the effect. There is much truth in this conclusion, but it remains indefensible.F. H. Bradley, 1893/1966, p. 48.

Integrating Personality Structure, Personality Process, and Personality Development

In this target article, we argue that personality processes, personality structure, and personality development have to be understood and investigated in integrated ways in order to provide comprehensive responses to the key questions of personality psychology. The psychological processes and mechanisms that explain concrete behaviour in concrete situations should provide explanation for patterns of variation across situations and individuals, for development over time as well as for structures observed in intra–individual and inter–individual differences. Personality structures, defined as patterns of covariation in behaviour, including thoughts and feelings, are results of those processes in transaction with situational affordances and regularities. It cannot be presupposed that processes are organized in ways that directly correspond to the observed structure. Rather, it is an empirical question whether shared sets of processes are uniquely involved in shaping correlated behaviours, but not uncorrelated behaviours (what we term ‘correspondence’ throughout this paper), or whether more complex interactions of processes give rise to population–level patterns of covariation (termed ‘emergence’). The paper is organized in three parts, with part I providing the main arguments, part II reviewing some of the past approaches at (partial) integration, and part III outlining conclusions of how future personality psychology should progress towards complete integration. Working definitions for the central terms are provided in the appendix. Copyright © 2017 European Association of Personality Psychology

Towards More Rigorous Personality Trait–Outcome Research

Much of personality research attempts to identify causal links between personality traits and various types of outcomes. I argue that causal interpretations require traits to be seen as existentially and holistically real and the associations to be independent of specific ways of operationalizing the traits. Among other things, this means that, to the extents that causality is to be ascribed to such holistic traits, items and facets of those traits should be similarly associated with specific outcomes, except for variability in the degrees to which they reflect the traits (i.e. factor loadings). I argue that, before drawing causal inferences about personality trait–outcome associations, the presence of this condition should be routinely tested by, for example, systematically comparing the outcome associations of individual items or facets, or sampling different indicators for measuring the same purported traits. Existing evidence suggests that observed associations between personality traits and outcomes at least sometimes depend on which particular items or facets have been included in trait operationalizations, calling trait–level causal interpretations into question. However, this has rarely been considered in the literature. I argue that when outcome associations are specific to facets, they should not be generalized to traits. Furthermore, when the associations are specific to particular items, they should not even be generalized to facets. Copyright © 2016 European Association of Personality Psychology

Causal Unity of Broader Traits is an Illusion

Mõttus alerts us to the widespread predictive heterogeneity of different indicators of the same trait. This heterogeneity violates the assumption that traits have causal unity in their developmental antecedents and effects on outcomes. I would go a step further: broader traits are useful units for description and prediction but not for explaining personality development and personality effects. In most cases, the measured trait indicators are closer to relevant causal mechanisms, and within a network perspective on personality, broader traits as entities with causal potential can be dismissed completely. Copyright © 2016 European Association of Personality Psychology

Age Differences in the Variance of Personality Characteristics

In contrast to mean–level comparisons, age group differences in personality trait variance have received only passing research interest. This may seem surprising because individual differences in personality characteristics are exactly what most of personality psychology is about. Because different proposed mechanisms of personality development may entail either increases or decreases in variance over time, the current study is exploratory in nature. Age differences in variance were tested by comparing the standard deviations of the five–factor model domain and facet scales across two age groups (20 to 30 years old versus 50 to 60 years old). Samples from three cultures (Estonia, the Czech Republic and Russia) were employed, and two methods (self–reports and informant–reports) were used. The results showed modest convergence across samples and methods. Age group differences were significant for 11 of 150 facet–level comparisons but never consistently for the same facets. No significant age group differences were observed for the five–factor model domain variance. Therefore, there is little evidence for individual differences in personality characteristics being systematically smaller or larger in older as opposed to younger people. We discuss the implications of these findings for understanding personality development. Copyright © 2015 European Association of Personality Psychology

Are Trait–Outcome Associations Caused by Scales Or Particular Items? Example Analysis of Personality Facets and Bmi

In personality research, trait–outcome associations are often studied by correlating scale sum scores with an outcome. For example, an association between the NEO Impulsiveness scale and body mass index (BMI) is often interpreted to pertain to underlying trait Impulsiveness. We propose that this expectation can be corroborated by testing for Spearman's theorem of indifference of indicator. Namely, an underlying trait–outcome association should not depend on the specific items (i.e. indicators) used to measure the trait. To test this theorem, we outline an indicator exclusion procedure and demonstrate its viability using a simulation design. We then apply this procedure to test personality–BMI associations for indifference of indicator in a large population–based sample of adult Estonians (N = 2581) using self–ratings and informant ratings obtained with the NEO Personality Inventory–3. Our results show that the N5: Impulsiveness–BMI association mostly depends on two eating–related items, suggesting that the trait associated with BMI may be narrower than the trait the N5: Impulsiveness scale is supposed to measure. Associations between BMI, E3: Assertiveness and C2: Order seem to pertain to the trait. In sum, testing for indifference of indicator provides a potentially useful method to clarify trait–outcome relationships. R scripts are provided that implement the indicator exclusion procedure. Copyright © 2015 European Association of Personality Psychology

Development of Indirect Measures of Conscientiousness: Combining a Facets Approach and Network Analysis

Because indirect measures of personality self–concepts such as the Implicit Association Test (IAT) allow tapping into automatic processes, they can offer advantages over self–report measures. However, prior investigations have led to mixed results regarding the validity of indirect measures of conscientiousness. We suggest that these results might be due to a failure to consider the different facets of conscientiousness. These facets are of crucial importance because they are associated differentially with other psychobiological constructs and they are also characterized by different mechanisms. Therefore, focusing on facets while developing indirect measures of conscientiousness may improve the validity of such measures. In Study 1, we conducted a psycholexical investigation to develop one IAT for each conscientiousness facet. In Study 2, we examined the convergent and discriminant validities of each facet IAT in relation to self–report measures, peer–report measures and self–report behavioural indicators, and we investigated differential associations of the conscientiousness facets with working memory capacity and self–control. We employed network analysis as a novel approach to elucidate differential relationships involving personality facets. The results corroborated the convergent and discriminant validity of the conscientiousness facet IATs with self–reports and showed that the conscientiousness facets were differentially associated with working memory capacity and with self–control. Copyright © 2015 European Association of Personality Psychology