Search

The authors explore the contributions of social and genetic influences to religious attitudes and practices in a population-based sample of 11-18 year olds and their mothers who responded to a Religious Attitudes and Practices Inventory and Religious Rearing Practices Inventory respectively. Contrary to genetic studies examining adult religious behavior, genetic influences were small, accounting for only 10 percent of the variance. Rather, the effects of the social environment were much larger, greater than 50 percent, and a majority of offspring similarity was explained by familial rearing. In light of the divergent finding between adolescents and adults, one supporting a socialization model and the other a genetic model, the importance of integrating genetic and social science methodology for complex social behaviors is discussed., Introduction It has been claimed that the social sciences are embedded in a paradigm that assumes social differences are purely socially determined (Alford, Funk and Hibbing 2005; Wilson 2002; Wozniak [...]

We combined experimental cognitive and behavior genetic methods to investigate storage and executive components of working memory in 663 middle-aged male twins. A single latent factor model indicated that digits forward (storage) and two-digit transformation (executive + storage) scores were influenced by the same genes. Additional executive demands in digit transformation appeared to increase the variance of individual genetic differences from 25% for digits forward to 48% and 53% for the digit transformation scores. Although it was not the best model, a two-factor model also provided a good fit to the data. This model suggested the possibility of a second set of genes specifically influencing the executive component. We discuss the findings in the context of research suggesting that new genetic influences come into play if demand continues to increase beyond a certain threshold, a threshold that may change with task difficulty and with age. Key Words: Cognitive psychology--Twin-behavior genetic methods Working memory.

Objective: Both genetic and common environmental influences contribute to twin associations for substance use; however, twin concordance rates may vary by environmental setting, indicating the presence of genetic-environmental interactions. The present study examined whether measures of family adaptability and cohesion may moderate the genetic influence on risk for alcohol use among female adolescents. Method: We examined such interactions through the application of log-linear models using data from the Virginia Twin Study of Adolescent Behavioral Development, a longitudinal study with extensive home interviews of adolescent (8-17 year old) female twins (386 monozygotic [MZ] pairs, 185 dizygotic [DZ] pairs) and their parents. Results: Twin concordance for alcohol use varied by average twin/parent reports of parental closeness. Differences between MZ-DZ correlations for alcohol use in families with low parental closeness, for example, were 0.97 and 0.67 (p < .001), respectively, compared with 0.79 and 0.73 (p = .24) for high parental closeness families. In addition, differences in twin concordance regardless of zygosity were found with greater twin similarities for alcohol use in strict families compared with leniently disciplined families, suggesting that the twin association interacts with common environmental influences on alcohol use. Conclusions: These results indicate that the genetic effects on adolescent alcohol use interact with the measured family environment and that the heritability of alcohol use may vary according to quality of the parental relationship. If confirmed, prevention programs may benefit from this knowledge, tailoring their intervention to quality of parental relationship., RECENT STUDIES ON ADOLESCENTS support evidence of genetic influences on alcohol use (Han et al., 1999; Hopfer et al., 2003; Maes et al., 1999; Rhee et al., 2003). Genetic influence [...]

This study used three instruments to assess genetic and phenotypic interrelationships related to symptoms of attention deficit hyperactivity disorder in same-sex twins. Findings indicate that behavioral symptoms like inattentiveness, impulsivity, and restlessness were strongly correlated across measures and that genetic modelling confirmed behavioral contrast effects between twins.

ABSTRACT. Objective: This study reports prevalences of lifetime and current alcohol, tobacco and drug use in adolescents; examines associations between substance use and a number of putative risk factors; and [...]

A sequential longitudinal study of behavioral development and psychopathology was conducted in a sample of twins aged 8 through 16 years. A high degree of correlation was found between separation anxiety disorder (SAD) and overanxious disorder (OAD) , between major depressive disorder (MDD) and OAD and between conduct disorder (CD) and oppositional defiant disorder (ODD). Girls reported more symptoms of MDD, SAD and OAD while boys reported more symptoms of CD and ODD.

The impact of genetic and environmental factors on behavioral problems was investigated by the Virginia Twin Study of Adolescent Behavioral Development in a sample of Caucasian twins aged 8-16 years. Results showed that monozygotic (MZ) twins correlated more highly than dizygotic (DZ) twins. DZ variances were greater than MZ variances and DZ correlations were low for measures of attention deficit hyperactivity disorder (ADHD). Measures of oppositional behavior and conduct disorder showed shared environmental effects.

Heritable influences are significant for the etiology of oral reading performance, while environmental influences, though significant, have a relatively small effect. The performance of twins in the Virginia Twin Study of Adolescent Behavioral Development in the Slosson Oral Reading Test shows that phenotypic variability is greater in males than in females. However, the relative significance of heritable and environmental influences does not vary by sex. Almost 69% of the phenotypic variance is caused by heritable influences, while 13% is accounted for by shared environmental influences.

The application of structural equation modeling to twin data is used to assess the impact of genetic and environmental factors on children's behavioral and emotional functioning. The models are applied to the maternal ratings of behavior of a subsample of 515 monozygotic and 749 dizygotic juvenile twin pairs, ages 8 through 16, obtained through mailed questionnaires as part of the Medical College of Virginia Adolescent Behavioral Development Twin Project. The importance of genetic, shared, and specific environmental factors for explaining variation is reported for both externalizing and internalizing behaviors, as well as significant differences in the causes of variation in externalizing behaviors among young boys and girls. The usefulness of applying structural equation models to data on monozygotic and dizygotic twins and the potential implications for addressing clinically relevant questions regarding the causes of psychopathology are discussed.

A study of a volunteer sample of older twins, regarding the genetic and environmental influences on alcohol-related problems over a life-time in individuals, reveals that the influences are independent of gender factors. Gender and age affect self-report measures of alcoholics' problems which were high among males. Alcohol-related problems were influenced by the age of the drinker, family history of alcohol problems and educational levels.

A survey of US volunteers comprising 3049 female and 1070 male twins, aged between 50 and 96, revealed major gender and age effects for self-report measures of current and lifetime alcohol consumption. Older volunteers exhibited higher trends in current and life time abstinence, while females reported less consumption. Lifetime and current alcohol consumption were similar in twins having a higher level of social contact. Genetic and shared environmental influence affected the onset of alcohol consumption in males and females. Biometrical genetic modeling confirmed the extremely familial nature of alcohol consumption.

A survey of 821 same-sex female twin pairs from a population-based registry assessed 8 dimensions of social support and social integration. Twin analyses documented significant common environmental influences on 5 of these 8 measures and significant ginetic influences on 5 of the 8. A decomposition of the multiplicative association between support and a measure of stressful life experiences in predicting depressed mood - an association typically interpreted as providing evidence for a stress-buffering effect of social support - shows clearly that it is the environmental and genetic factors that cause support, rather than support itself, that buffer the effects of stress on mood in most cases. We discuss the implications of this result for future research on the relationship between social support and psychopathology.

The conduct disorder, of children belonging to intact families, is compared with children from stepfather families, with alcoholism as a prevailing factor. This study explains the way divorce affects the children and is the main cause of adolescent problems.

A discussion on the role of children of twins (COT) design strength with specific environment is carried out. The results show that design plays a unique role in the study of developmental psychology and psychopathology.

Research on twins examines how the parent-child relationship influences child behavioral problems and psychopathology. Topics include how differential treatment of siblings in families impacts psychopathological risk.

The relationship between parental psychiatric disorders and children's psychiatric symptoms are assessed using a sample of 850 twin families. Symptoms of depression and over anxious disorder are related to parental depression, with maternal depression causing higher risks.