Views on aging are central psychosocial variables in the aging process, but knowledge about their determinants is still fragmental. Thus, the authors investigated the degree to which genetic and environmental factors contribute to individual differences in various domains of views on aging (wisdom, work, fitness, and family), and whether these variance components vary across ages. They analyzed...

OBJECTIVES Self-rated health has been shown to be a predictor for future health status and mortality. The purpose of this study was to investigate age-group and sex differences in genetic and environmental sources of variation for self-rated health. METHODS A sample of twins from the Swedish Twin Registry participated in a computer-assisted telephone interview with assessment of self-rated he...

BACKGROUND AND OBJECTIVES There is no doubt that the dramatic worldwide increase in obesity prevalence is due to changes in environmental factors. However, twin and family studies suggest that genetic differences are responsible for the major part of the variation in adiposity within populations. Recent studies show that the genetic effects on body mass index (BMI) may be stronger when combined...

CONTEXT Although pathological gambling (PG) and major depression (MD) frequently co-occur, little is known regarding the relative contributions of environmental and genetic factors to the codevelopment of the disorders. OBJECTIVES To estimate environmental and genetic contributions to PG and MD as defined in DSM-III-R and the lifetime co-occurrence of PG and MD. DESIGN Survey data from the ...

Dry matter grain yield per plot from three genetically homogeneous single-cross maize hybrids were analysed to investigate whether environmental variance depends on genotype. Three genotypes were tested at 20 locations in 3 years. The data were analysed using a non-parametric approach and fully parametric Bayesian models. Both analyses reveal effects of genotype on environmental variation. The ...

today, environmental threats are in center of important questions’ human conscience twenty-first century. these questions have attracted public opinions quit alarming and they posed extreme sensitivity to the environment on a global level. this study aimed at understanding the role of social structural factors on the gap between environmental attitudes and behavior carried out. population invol...

For a quantitative genetic study of pre-school problem behaviours, we have collected data with the Child Behavior Checklist for 2 and 3-year-old children (CBCL 2/3). Questionnaires were completed by mothers of 3620 twin pairs: 633 monozygotic males, 581 dizygotic males, 695 monozygotic females, 519 dizygotic females and 1192 dizygotic opposite sex twin pairs. The genetic and environmental influ...

BACKGROUND Dissociation--a pattern of general disruption in memory and consciousness--has been found to be an important cognitive component of children's and adults' coping with severe trauma. Dissociative experiences include amnesia, identity disturbance, age regression, difficulty with concentration, and trance states. Stable individual differences in dissociative behaviors may represent a di...

Modern personality theories differ in their assumptions about the structure and etiology of the interplay between personality traits and motivational constructs. The present study examined the genetic and environmental sources of the interplay between the Big Five and major life goals concurrently and across time in order to provide a more decisive evaluation of the conflicting assumptions stat...

The demographic variance of an age-structured population is defined. This parameter is further split into components generated by demographic stochasticity in each vital rate. The applicability of these parameters are investigated by checking how an age-structured population process can be approximated by a diffusion with only three parameters. These are the deterministic growth rate computed f...