Richard Rende

Sisters, brothers, and delinquency: evaluating social influence during early and middle adolescence.

Although a number of studies have shown that brothers are highly correlated for delinquent behavior, much less research has been conducted on sisters. We propose that sisters, like brothers, show notable similarity for delinquent behavior, and also promote each others delinquency through direct interaction. We examined these issues in 164 brother and sister pairs studied over a 4-year period (from early to middle adolescence) in a study of intact families in the rural Midwest. Sibling similarity for self-reports of delinquent behavior were highly correlated for both brothers and sisters. Conditional effects of high levels of hostile-coercive sibling relationships and older sibling delinquency predicted younger sibling delinquency in both brother and sister pairs. For brothers, conditional effects were also detected for high levels of warmth-support, in contrast to sisters. The conditional effects of older sibling delinquency and relationship quality were shown to predict change in younger sibling delinquency through adolescence. The results add to a growing literature on sibling effects as well as theoretical models that emphasize the role of social interaction between siblings as a risk factor for the development of delinquent activity in adolescence.

Educational attainment and cigarette smoking: a causal association?

BACKGROUND Despite abundant evidence that lower education is associated with a higher risk of smoking, whether the association is causal has not been convincingly established. METHODS We investigated the association between education and lifetime smoking patterns in a birth cohort established in 1959 and followed through adulthood (n = 1311). We controlled for a wide range of potential confounders that were measured prior to school entry, and also estimated sibling fixed effects models to control for unmeasured familial vulnerability to smoking. RESULTS In the full sample of participants, regression analyses adjusting for multiple childhood factors (including socioeconomic status, IQ, behavioural problems, and medical conditions) indicated that the number of pack-years smoked was higher among individuals with less than high school education [rate ratio (RR) = 1.58, confidence interval (CI) = 1.31, 1.91]. However, in the sibling fixed effects analysis the RR was 1.23 (CI = 0.80, 1.93). Similarly, adjusted models estimated in the full sample showed that individuals with less than high school education had fewer short-term (RR = 0.40; CI = 0.23, 0.69) and long-term (RR = 0.59; CI = 0.42, 0.83) quit attempts, and were less likely to quit smoking (odds ratio = 0.34; CI = 0.19, 0.62). The effects of education on quitting smoking were attenuated in the sibling fixed effects models that controlled for familial vulnerability to smoking. CONCLUSIONS A substantial portion of the education differential in smoking that has been repeatedly observed is attributable to factors shared by siblings that contribute to shortened educational careers and to lifetime smoking trajectories. Reducing disparities in cigarette smoking, including educational disparities, may therefore require approaches that focus on factors early in life that influence smoking risk over the adult life span.

Longitudinal Relations between Temperament Traits and Behavioral Syndromes in Middle Childhood

OBJECTIVE This study tested Graham and Stevensons 1987 hypothesis specifying links between EAS (emotionality-activity-sociability) temperament traits and behavioral syndromes of depression, hyperactivity, and delinquency in an unselected sample of 164 children in infancy and early childhood. METHOD Mothers completed the Colorado Child Temperament Inventory. Each mother also used the Child Behavior Checklist (CBCL) to report on her childs behavior problems after the childs completion of first grade. Scores on three CBCL scales, anxiety/depression, attention problems, and delinquent behavior, were examined in relation to the EAS traits. RESULTS For boys, high emotionality in infancy and early childhood was associated with high scores on both the anxiety/depression and attention problem scales. For girls, both high emotionality and low sociability predicted high scores on the anxiety/depression scale. There were no associations between EAS traits and attention problems for girls. There was little evidence for links between EAS traits and delinquent behavior for either boys or girls. CONCLUSIONS The results are discussed with respect to temperamental traits as risk factors for the emergence of behavior problems in childhood.

Sibling Effects on Substance Use in Adolescence: Social Contagion and Genetic Relatedness

Prior research on sibling contagion for substance use has not attended to individual differences in the sibling relationship that may be influenced by genetic similarity. The authors utilizing data on a sample of twin and nontwin siblings participating in the National Longitudinal Study of Adolescent Health (Add Health). Although monozygotic twins had the highest levels of sibling contact and mutual friendships, the pattern of results for other sibling types were not consistent with genetic models, and biometric analysis indicated that shared environmental factors influenced these sibling relationship features. Application of DeFries-Fulker regression models provided evidence that sibling contact and mutual friendships represent a source of social contagion for adolescent smoking and drinking independent of genetic relatedness. The results are interpreted using a social contagion framework and contrasted with other competing models such as those focused on the equal environments assumption and niche selection.

Genetic and Environmental Influences on Maternal and Sibling Interaction in Middle Childhood: A Sibling Adoption Study.

Genetic and environmental influences on maternal and sibling interactions were examined in 67 mother-child-child triads from nonadoptive families and 57 mother-child-child triads from adoptive families (in which both children were adopted and genetically unrelated). Triads were videotaped in 6 play settings in their homes. In addition, each sibling pair was observed in an unstructured setting in the home, and mothers completed an interview about the sibling relationship

A Twin Study of Smoking, Nicotine Dependence, and Major Depression in Men

This study examined the nature of the relationship among lifetime major depression, smoking, and nicotine dependence. Subjects were 8,169 male twins from the Vietnam Era Twin Registry. Biometrical modeling demonstrated a genetic influence on daily smoking, nicotine dependence, and major depression, and a family environmental influence on daily smoking. Genetic factors influencing nicotine dependence also strongly influenced major depression. We also compared probands with a history of major depression (n = 398) from pairs discordant for major depression, their nondepressed cotwins (n = 364), and controls (n = 1,863) on a number of secondary smoking outcomes. Major depression was associated with current daily smoking and certain nicotine withdrawal symptoms. Individuals with a familial vulnerability for major depression, even without a personal history of major depression, were more likely to smoke despite a serious illness and to report nervousness, restlessness, difficulty concentrating, and depressed mood during past quit attempts. Among the 237 monozygotic pairs discordant for major depression, depressed probands were more likely to have a lifetime history of nicotine dependence than were cotwins. Findings extend Kendler and colleagues (1993) study of female twins by demonstrating in men that shared genetic factors predispose not only to major depression and daily smoking but also to major depression and nicotine dependence.

Diathesis-stress models of psychopathology: A quantitative genetic perspective*

Abstract When genetics is considered in diathesis-stress models of psychopathology, it is often assumed that heredity provides the diathesis and environmental factors are responsible for the stressor. We discuss two quantitative genetic models relevant to the diathesis-stress construct. One model focuses on genotype-environment interaction, which is the usual way in which genetic influence is represented in diathesis-stress models. A second model—genotype-environment correlation—provides an alternative that represents both genetic and environmental influences relevant to the development of psychopathology. Implications of these models for clinical research are discussed.

Who discovered the twin method

The twin method is usually credited to Francis Galtons 1875 article on twins. However, Galton did not propose the comparison between identical and fraternal twin resemblance which is the essence of the twin method. Although the twin method was “in the air” in the mid-1920s, the first descriptions of the method appeared in an article by Curtis Merriman and in a book by Hermann Siemens, both in 1924, 50 years after Galtons paper.

Anxiety in middle adulthood: effects of age and time on the 14-year course of panic disorder, social phobia and generalized anxiety disorder

BACKGROUND Much about the long-term course of anxiety disorders is unknown. The present study utilizes a naturalistic, longitudinal, short-interval follow-up design to elucidate the course of anxiety disorders over 14 years in a largely middle-aged adult sample recruited from out-patient psychiatry and primary care facilities. METHOD The sample consisted of 453 participants with a diagnosis of panic disorder (PD), social phobia (SP) and/or generalized anxiety disorder (GAD). Anxiety symptom ratings were tracked using weekly psychiatric status ratings (PSRs). Controlling for demographic and clinical variables, the course of PD, GAD and SP were examined using longitudinal growth models, with the most severe PSR at each follow-up point as the main outcome variable. RESULTS PSRs significantly decreased in severity over time in each of the three disorders. In the interaction effects models, age x time had a significant effect on course for PD and GAD, but not for SP, in that older age was associated with lower PSRs over time. CONCLUSIONS The present findings suggest that the severity of anxiety disorders declines over time, although this decline is modest and depends on the specific disorder being assessed. Older individuals with PD and GAD have a better prognosis than their younger counterparts, as their course is characterized by a steeper decline in severity. The present findings provide important information about the course of anxiety disorders in mid-life.

Parental smoking exposure and adolescent smoking trajectories.

OBJECTIVE: In a multigenerational study of smoking risk, the objective was to investigate the intergenerational transmission of smoking by examining if exposure to parental smoking and nicotine dependence predicts prospective smoking trajectories among adolescent offspring. METHODS: Adolescents (n = 406) ages 12 to 17 and a parent completed baseline interviews (2001–2004), and adolescents completed up to 2 follow-up interviews 1 and 5 years later. Baseline interviews gathered detailed information on parental smoking history, including timing and duration, current smoking, and nicotine dependence. Adolescent smoking and nicotine dependence were assessed at each time point. Latent Class Growth Analysis identified prospective smoking trajectory classes from adolescence into young adulthood. Logistic regression was used to examine relationships between parental smoking and adolescent smoking trajectories. RESULTS: Four adolescent smoking trajectory classes were identified: early regular smokers (6%), early experimenters (23%), late experimenters (41%), and nonsmokers (30%). Adolescents with parents who were nicotine-dependent smokers at baseline were more likely to be early regular smokers (odds ratio 1.18, 95% confidence interval 1.05–1.33) and early experimenters (odds ratio 1.04, 95% confidence interval 1.04–1.25) with each additional year of previous exposure to parental smoking. Parents’ current non-nicotine–dependent and former smoking were not associated with adolescent smoking trajectories. CONCLUSIONS: Exposure to parental nicotine dependence is a critical factor influencing intergenerational transmission of smoking. Adolescents with nicotine-dependent parents are susceptible to more intense smoking patterns and this risk increases with longer duration of exposure. Research is needed to optimize interventions to help nicotine-dependent parents quit smoking early in their children’s lifetime to reduce these risks.