Beyond Heritability: Twin Studies in Behavioral Research

ABSTRACT— The heritability of human behavioral traits is now well established, due in large measure to classical twin studies. We see little need for further studies of the heritability of individual traits in behavioral science, but the twin study is far from having outlived its usefulness. The existence of pervasive familial influences on behavior means that selection bias is always a concern in any study of the causal effects of environmental circumstances. Twin samples continue to provide new opportunities to identify causal effects with appropriate genetic and shared environmental controls. We discuss environmental studies of discordant twin pairs and twin studies of genetic and environmental transactions in this context.     

Gender differences in unilateral spatial neglect within 24 hours of ischemic stroke

Hemispatial neglect is a common and disabling consequence of stroke. Previous reports examining the relationship between gender and the incidence of unilateral spatial neglect (USN) have included either a large numbers of patients with few neglect tests or small numbers of patients with multiple tests. To determine if USN was more common and/or severe in men or women, we examined a large group of patients (312 right-handed) within 24 hours of acute right hemisphere ischemic stroke. Multiple spatial neglect tasks were used to increase the sensitivity of neglect detection. No differences based upon gender were observed for the prevalence, severity, or a combined task measure of USN.     

Relational‐Cultural Theory: A Framework for Bridging Relational,Multicultural, and Social Justice Competencies

Relational‐cultural theory (RCT) theorists advocate expanding the multicultural/social justice counseling competencies beyond the domains of self‐awareness, cultural knowledge, and culturally responsive helping skills. This article provides an overview of RCT and discusses how creating and participating in growth‐fostering relationships are essential dimensions of human development and psychological well‐being. Implications of this theoretical model for counseling practice are also addressed.     

The Utility of the SASSI‐3 in Early Detection of Substance Use Disorders in Not Guilty by Reason of Insanity Acquittees: An Exploratory Study

Previous studies have shown the Substance Abuse Subtle Screening Inventory‐3 (G. Miller, 1999) to be valid in classifying substance use disorders in forensic and mentally ill populations. The authors found that it also correctly classified substance use disorders in the understudied not guilty by reason of insanity population.     

An Empowerment Evaluation Model for Sexual Assault Programs: Empirical Evidence of Effectiveness

Using an empowerment evaluation approach, the Sexual Assault and Rape Prevention (SARP) Evaluation Project brought together university researchers, public health evaluators, state funders, and program staff to provide evaluation training and consultation to all state-funded rape prevention and victim services programs in Michigan. In this paper, the specific activities of the SARP project are described, and process and outcome data are presented that address the effectiveness of this empowerment evaluation approach. Based on subjective reports from program staff and objective data obtained from state funders, results suggest that this evaluation model was successful in helping 90% of the prevention programs and 75% of the victim services programs successfully develop and launch program evaluations. One-year follow-up data indicate that 90% of the programs had sustained their evaluation efforts after the formal work of the SARP project had ended.     

The Social Networks of Women Experiencing Domestic Violence

The research literature has demonstrated that battered women living in shelters experience impaired social support. This study examines this phenomenon among battered women living in the community. This study compared a group of pregnant battered women (n = 145) and a group of pregnant nonbattered women (n = 58) in terms of their structural [e.g., total number of supporters, network members in violent relationships with their partners (an index of homophily or nonhomophily) and functional (e.g., emotional)] social support. Four reasons for impaired support in battered women were proposed and examined, including social isolation, failure to disclose abuse, homophily, and low SES. Only homophily was related to impaired support among battered women. In addition, the relationship between structural and functional support and mental health outcomes (e.g., depression, self-esteem) was examined. Criticism, practical support, homophily, and disclosure were all significant predictors of mental health for battered women. Implications for community-based interventions are discussed in the context of current intervention strategies with battered women.     

The Influence of Community Violence on the Functioning of Women Experiencing Domestic Violence

The relationships among women’s experiences of domestic violence, community violence, and their mental health functioning were explored (N = 94). Social contagion theory was used to argue for the link between community violence and family violence. Results revealed that women’s experiences of domestic violence were not related to community violence. Furthermore, women’s mental health functioning was solely associated with their experiences of domestic violence, not with community violence. Results are discussed in terms of an ecological model of domestic violence and future directions for exploring linkages between neighborhood characteristics and individual experiences.     

Normal and abnormal personality traits: evidence for genetic and environmental relationships in the Minnesota Study of Twins Reared Apart

ABSTRACT Recent studies have demonstrated substantial correlations between normal and abnormal personality traits. Yet little is known about how these correlations are mediated genetically and environmentally: Do normal and abnormal personality traits stem from the same underlying genes and environments? We addressed this question using data from 128 monozygotic and dizygotic twin pairs in the Minnesota Study of Twins Reared Apart (MISTRA). Additive genetic and nonshared environmental correlations between scales of the Minnesota Multiphasic Personality Inventory (MMPI)—an index of abnormal personality—and the Multidimensional Personality Questionnaire (MPQ)—an index of normal personality—were estimated. Results indicated that phenotypic correlations between normal and abnormal personality were mediated by genetic as well as environmental factors, although the magnitude of genetic mediation tended to be larger overall. Moreover, the patterns of phenotypic, genetic, and environmental relationships among the scales were similar, suggesting that influences on normal and abnormal personality act through systems common to both. It is suggested that future research focus on the neurogenetic substrates of these shared systems and how dysfunction in these systems influences development of disordered personality.     

Surface construal and the mental representation of scenes

What distinguishes scenes from nonscenes? Photographs of objects on both naturalistic and blank backgrounds yielded boundary extension (BE: memory for unseen spatial expanse outside the picture's boundaries). However, line-drawn objects on blank backgrounds did not (Experiment 1). Perhaps the blank background was construed as depicting a real-world surface in the photograph condition but was construed as depicting nothing in the line-drawn condition. To change background construal, the authors used objects cut out of photographs; these were placed on blank backgrounds while viewers watched (Experiments 2 and 3). BE was eliminated. The authors propose that amodal continuation is a fundamental aspect of scene perception. However, not all pictures are scenes--only pictures construed as depicting a truncated view of a continuous world.     

Acquisition,Extinction, Recovery,and Reversal of Different Response Sequences Under Conditional Control by Nicotine in Rats

Complex voluntary behaviors occur in sequence. Eight rats were trained in an operant procedure that used nicotine and non-drug (saline) states as interoceptive cues that signaled which of two behavioral sequences led to food reward. The distal and proximal responses in the chain were always maintained on variable interval 30-sec and fixed ratio-1 schedules, respectively, and rate differences between the responses were used as the dependent variable. Extinction and reversal training was conducted. Distal response rates were significantly greater than proximal response rates during training, testing, extinction, and reversal learning. These data suggest that (a) nicotine can establish interoceptive control over different response sequences, and (b) extinction of one response sequence may be state-dependent. The clinical relevance of extinction of complex behavioral repertoires such as drug-seeking and drug-taking behavior that are evoked by specific interoceptive cues is addressed in regard to drug abuse treatment and relapse.