National character does not reflect mean personality trait levels in 49 cultures.

Most people hold beliefs about personality characteristics typical of members of their own and others' cultures. These perceptions of national character may be generalizations from personal experience, stereotypes with a "kernel of truth," or inaccurate stereotypes. We obtained national character ratings of 3989 people from 49 cultures and compared them with the average personality scores of culture members assessed by observer ratings and self-reports. National character ratings were reliable but did not converge with assessed traits. Perceptions of national character thus appear to be unfounded stereotypes that may serve the function of maintaining a national identity.

Sources of structure: genetic, environmental, and artifactual influences on the covariation of personality traits.

The phenotypic structure of personality traits has been well described, but it has not yet been explained causally. Behavior genetic covariance analyses can identify the underlying causes of phenotypic structure; previous behavior genetic research has suggested that the effects from both genetic and nonshared environmental influences mirror the phenotype. However, nonshared environmental effects are usually estimated as a residualterm that may also include systematic bias, such as that introduced by implicit personality theory. To reduce that bias, we supplemented data from Canadian and German twin studies with cross-observer correlations on the Revised NEO Personality Inventory. The hypothesized five-factor structure was found in both the phenotypic and genetic/familial covariances. When the residual covariance was decomposed into true nonshared environmental influences and method bias, only the latter showed the five-factor structure. True nonshared environmental influences are not structured as genetic influences are, although there was some suggestion that they do affect two personality dimensions, Conscientiousness and Love. These data reaffirm the value of behavior genetic analyses for research on the underlying causes of personality traits.

Covariance structure of neuroticism and agreeableness: a twin and molecular genetic analysis of the role of the serotonin transporter gene.

The Revised NEO Personality Inventory domains of Neuroticism and Agreeableness are considered factorially distinct despite several intercorrelations between these domains. The genetic correlation, an index of the degree to which these intercorrelations are caused by genetic influences, was estimated using data from 913 monozygotic and 562 dizygotic volunteer twin pairs from Canada, Germany, and Japan. The serotonin transporter gene, 5-HTTLPR, was assayed in a sample of 388 nontwin sibling pairs from the United States to determine the contribution of the serotonin transporter locus to the covariation between the Neuroticism and Agreeableness scales. In all four samples, genetic influences contributed to the covariance of Neuroticism and Agreeableness, with the serotonin transporter gene accounting for 10% of the relationship between these domains.

Genetic and environmental influences on observed personality: evidence from the German Observational Study of Adult Twins.

Previous behavior-genetic research on adult personality relied primarily on self-reports or peer reports that may be subject to contrast effects, resulting in biased estimates of genetic and environmental influences. In the German Observational Study of Adult Twins (GOSAT), personality traits of 168 monozygotic (MZ) and 132 dizygotic (DZ) twin pairs were rated on 35 adjective scales, largely markers of the Big 5. The ratings were provided by 120 judges who never met the twins but observed videotaped behaviors of 1 twin of each pair in 1 of 15 different settings. The aggregated video-based trait ratings were highly reliable, and substantial correlations were obtained between MZ as well as DZ twins. Model-fit analyses suggested about 40% genetic, 25% shared environmental, and 35% nonshared environmental influence. Extraversion was the only trait that seemed not to be influenced by shared environment.

On the invalidity of validity scales: evidence from self-reports and observer ratings in volunteer samples.

Because of the potential for bias and error in questionnaire responding, many personality inventories include validity scales intended to correct biased scores or identify invalid protocols. The authors evaluated the utility of several types of validity scales in a volunteer sample of 72 men and 106 women who completed the Revised NEO Personality Inventory (NEO-PI-R; P. T. Costa & R. R. McCrae, 1992) and the Multidimensional Personality Questionnaire (MPQ; A. Tellegen, 1978/1982) and were rated by 2 acquaintances on the observer form of the NEO-PI-R. Analyses indicated that the validity indexes lacked utility in this sample. A partial replication (N = 1,728) also failed to find consistent support for the use of validity scales. The authors illustrate the use of informant ratings in assessing protocol validity and argue that psychological assessors should limit their use of validity scales and seek instead to improve the quality of personality assessments.

Nature over nurture: temperament, personality, and life span development.

Temperaments are often regarded as biologically based psychological tendencies with intrinsic paths of development. It is argued that this definition applies to the personality traits of the five-factor model. Evidence for the endogenous nature of traits is summarized from studies of behavior genetics, parent-child relations, personality structure, animal personality, and the longitudinal stability of individual differences. New evidence for intrinsic maturation is offered from analyses of NEO Five-Factor Inventory scores for men and women age 14 and over in German, British, Spanish, Czech, and Turkish samples (N = 5,085). These data support strong conceptual links to child temperament despite modest empirical associations. The intrinsic maturation of personality is complemented by the culturally conditioned development of characteristic adaptations that express personality; interventions in human development are best addressed to these.

Age differences in personality across the adult life span: parallels in five cultures.

Both cross-sectional and longitudinal studies in the United States have shown consistent changes between college age and middle adulthood. There appear to be declines in 3 of the 5 major factors of personality--Neuroticism, Extraversion, and Openness--and increases in Agreeableness and Conscientiousness. To examine cross-cultural generalizability of these findings, translations of the Revised NEO Personality Inventory were administered to samples in Germany, Italy, Portugal, Croatia, and South Korea (N = 7,363). Similar patterns of age differences were seen in each country, for both men and women. Common trends were also seen for the more specific traits that define the major factors. Because these nations differ substantially in culture and recent history, results suggest the hypothesis that these are universal maturational changes in adult personality.

Heritability of facet-level traits in a cross-cultural twin sample: support for a hierarchical model of personality.

The common variance among personality traits can be summarized in the factors of the five-factor model, which are known to be heritable. This study examined heritability of the residual specific variance in facet-level traits from the Revised NEO Personality Inventory. Analyses of raw and residual facet scales across Canadian (183 monozygotic [MZ] and 175 dizogotic [DZ] pairs) and German (435 MZ and 205 DZ pairs) twin samples showed genetic and environmental influences of the same type and magnitude across the 2 samples for most facets. Additive genetic effects accounted for 25% to 65% of the reliable specific variance. Results provide strong support for hierarchical models of personality that posit a large number of narrow traits in addition to a few broader trait factors or domains. Facet-level traits are not simply exemplars of the broad factors they define; they are discrete constructs with their own heritable and thus biological basis.

The serotonin transporter gene and peer-rated neuroticism.

Polymorphisms in the serotonin transporter gene (5HTT) have been reported to be associated with neuroticism (emotionality) and with depression. A recent report of an association between 5HTT and neuroticism involved unselected samples and self-report questionnaires. We attempted to extend these findings using a selected extremes design and peer ratings. From a sample of 2085 individuals, each assessed on neuroticism by two independent peers, we selected 52 individuals from the top 5% and 54 individuals from the bottom 5%. No association was found for either a functional 44 bp insertion/deletion polymorphism in 5HTT regulatory sequence (5HTTLPR) or for a non-functional variable number tandem repeat 5HTT polymorphism.

[Longitudinal changes in rigidity in old age]. / Längsschnittliche Veränderungen der Rigidität im Alter.

This investigation attempted to deal with the question of longitudinal changes in the rigidity of attitudes and behaviour in a sample of elderly persons (68--90 years old). This was done by collecting data twice (1969/70 and 1976) from 86 subjects on a serie of measures of rigidity. At the same time additional data were collected on external variables such as intelligence, anxiety, state of health, extraversion, neuroticism, etc. Analyses of variance with the factors "time of measurement" and "sex" indicated a change in the predicted direction for the majority of the measures used. After an internal of six years, the capacity for adaptive and spontaneous flexibility had decreased, whereas intolerance and dispositional rigidity had increased. On the Riegel-scales R1 and R2, a rise in age was accompanied by a rise in rigidity, as measured in terms of statement in the form of personal judgments. Agreement with other judgments in the form of more generally formulated statements, on the other hand, decreased. Sex differences were found for Brengelmann's NR-scale and the Gottschaldt Hidden Figure test. Women were found to be less rigid than men, but also revealed less adaptive flexibility. A comparison of the test scores of longitudinal subjects and a comparable group of control group subjects yielded no signs of differences which would be traced back to a biased selection of the longitudinal sample.

Health, socioeconomic status and self-preception in the elderly: An application of the interpersonal checklist.

One-hundred and thirty-four men and women in the Bonn Longitudinal Study of Aging (BLSA) sample from sixty-two to eighty-one years of age were tested and re-tested a year later using the Interpersonal Checklist (ICL) to study the effects of health, sex, socioeconomic status and time of self perception. Preliminary item analysis justified the use of the ICL for older people. A multiple analysis of variance for repeated measures with the factors SEX, SES, and TIME yielded two interactions for "rebellious-distrustful (FG by sex x health) and "self effacing-masochistic" (HI by time x health) and three main-effects for "agressive-sadistic" (DE by sex), "self-effacing-masochistic" (HI by SES) and "docile-dependent" (IK by time).

The pooling of logitudinal studies of aging.

This report describes the pooling of 5 longitudinal studies conducted during the last 20 years in West Germany. The pooling provides the following improvements: By increasing the number of participants the reliability and precision of the results are improved. The sample becomes representative of the whole area of the FRG. Both cohort and age comparisons are improved by extending their ranges. The time-of-testing range is increased from 5 to 17 years. Since the significance of this factor has been recognized often but since few empirical explorations have been made in the past, the extension of the time-of-testing range represents the most important contribution of the present work. The pooling of different studies is possible only if they share a common set of methods. This requirement is met under the present conditions. Moreover, each study adds unique methods to the pool, thus, supplementing the common explorations in a constructive manner.