Suchergebnisse

AbstractThe physiological benefits of vigorous exercise are well established. The existence of psychological benefits is less clear, however, due to methodological limitations common to investigatory studies. Two of these limitations are the difficulty of establishing appropriate control groups and the large variety of highly specific measures of psychological function available for consideration of effects. To address these limitations, we identified 63 pairs of monozygotic twins from the National Survey of Midlife Development in the United States who were discordant for the amount of vigorous exercise in which they engaged regularly. The twins who regularly engaged in vigorous exercise experienced greater positive psychological functioning than their nonexercising co-twins as measured by the latent factor representing the variance common to 8 measures of mood, optimism, control over life, and interpersonal aspects of personality. The magnitude of the difference was in excess of .4 standard deviations.

AbstractThe Minnesota Center for Twin and Family Research (MCTFR) houses a collection of longitudinal, community-based twin-family and adoptee-family projects that focus on the mental health outcomes of adolescent youth with a special focus on the development of substance use and related behavior disorders. The Minnesota Twin Family Study includes epidemiological investigations of 11- and 17-year-old twins, an examination of 11-year-old twins selected for being at high risk for having a childhood disruptive behavior disorder, and a supplemental registry of young adult twins age 18 years and older who are not enrolled in these longitudinal studies. Also, part of the MCTFR is the Sibling Interaction and Behavior Study, a complementary prospective investigation of adolescent sibling pairs in families with adoptive and biological offspring. MCTFR participants from these various projects are assessed in person and through multiple informants to provide comprehensive coverage of psychological adjustment, mental health, and psychosocial risk/protective factors. Measurement of EEG and autonomic nervous system reactivity is also part of the assessment battery for twin families. This article provides an overview of study design and includes a review of recent MCTFR findings.

Both partner abuse and general crime violate the rights and safety of victims. But are these phenomena the same or are they distinct, demanding their own research and intervention specialties? Are per‐ sons who abuse their partners the same people who commit other criminal behavior? Do partner abuse and general crime share the same correlates? We investigated these questions in a birth cohort of over 800 young adults, by testing whether a personality model known to predict general crime would also predict partner abuse. Personality data were gathered at age 18, and self‐reported partner abuse and general criminal offending were measured at age 21. Results from modeling latent constructs showed that partner abuse and general crime represent different constructs that are moderately related; they are not merely two expressions of the same underlying antisocial propensity. Group comparisons showed many, but not all, partner abusers also engaged in violence against nonintimates. Personality analyses showed that partner abuse and general crime shared a strong propensity from a trait called Negative Emotionality. However, crime was related to weak Constraint (low self‐control), but partner abuse was not. All findings applied to women as well as to men, suggesting that women's partner abuse may be motivated by the same intra‐personal features that motivate men's abuse. The results are consistent with theoretical and applied arguments about the "uniqueness" of partner violence relative to other crime and violence.

AbstractTwin studies have demonstrated that personality traits show moderate genetic influence. The conclusions drawn from twin studies rely on the assumptions that twins are representative of the population at large and that monozygotic and dizygotic twins are comparable in every way that might have bearing on the traits being studied. To evaluate these assumptions, we used Multidimensional Personality Questionnaire (MPQ) data from three samples drawn from the Minnesota Twin Registry (totaling 12,971 respondents) to examine the effect sizes associated with mean differences on the 11 MPQ scales and 3 higher-order MPQ factors for singletons versus twins and MZ twins versus DZ twins. The singletons in the samples were family members of the participating twins. We also used ratios of scale variances to examine the significance of variance differences. The only mean or variance difference replicated across all three samples was greater Social Closeness (about .1 standard deviation) for twins than for singletons. This difference was obtained for both males and females. It would appear that, with respect to personality, twins are not systematically different from other people. Our results also highlight the importance of replication in psychological research because each of our large samples showed differences not replicated in other samples.

We examined the relation between personality traits and crime in two studies. In New Zealand we studied 18‐year‐old males and females from an entire birth cohort. In Pittsburgh we studied an ethnically diverse group of 12‐ and 13‐year‐old boys. In both studies we gathered multiple and independent measures of personality and delinquent involvement. The personality correlates of delinquency were robust in different nations, in different age cohorts, across gender, and across race: greater delinquent participation was associated with a personality configuration characterized by high Negative Emotionality and weak Constraint. We suggest that when Negative Emotionality (the tendency to experience aversive affective states) is accompanied by weak Constraint (difficulty in impulse control), negative emotions may be translated more readily into antisocial acts. We review additional evidence about the developmental origins and consequences of this personality configuration and discuss its implications for theories about antisocial behavior.

AbstractExisting research shows that ideological orientations are stable after young adulthood. Extending research on the sources of ideological stability, we examine social and economic ideology over a 3- to 4-year period in two twin panels (one Danish and one American). We find evidence for the importance of genetic influences and individual life experiences on the stability of social ideology in both contexts; shared environmental factors play an important role in the younger, Danish sample only. For economic ideology, genetic factors contribute to stability in the American sample only. Our findings show that the role of genetic and environmental factors in the stability of ideological orientations varies by type of ideology, national context, and, possibly, age cohort.