Tacit coordination in monozygotic twins, dizygotic twins and virtual twins: Effects and implications of genetic relatedness

Game theorists have long been interested in why some partners are more successful at achieving mutual goals than others. The present study was conducted to determine if tacit coordination (non-negotiated consensus) varies as a function of genetic relatedness between social partners. The sample included 7–13-year-old monozygotic (MZ) twin pairs (n = 53), dizygotic (DZ) twin pairs (n = 85) and virtual twin (VT) pairs (n = 42; same-age unrelated siblings). Co-twin agreement on questions completed under individual and coordination conditions was compared across the three groups. MZ twins showed significantly greater overall agreement than DZ twins and VTs, using multiple criteria. The implications of these findings are considered with reference to behavioral-genetic and evolutionary theories of behavior.     

Peer-Delivered Models for Caregivers of Children and Adults with Health Conditions: A Review

Peer-delivered health models may hold important benefits for family members, yet their prevalence, components, and outcomes are unknown. We conducted a review of peer-delivered services for families of children and adults with serious health problems. Studies of interventions published between 2000 and 2016 were included if the intervention contained a component for family members. Of 88 studies that were assessed for their eligibility, five met criteria. Familial components included information about the health condition and management, strategies to enhance communication and stress, and the provision of emotional support. Outcomes were largely favorable, including reductions in distress and symptoms of trauma, enhanced quality of life, and positive perceptions of the peer therapeutic alliance. Peer-delivered services for family members may hold important benefits to caregivers; however, the research base remains thin. A research agenda to develop and examine these models is discussed.     

First record: a methodological approach to counter sampling bias

One goal of survey research is to optimize sampling procedures so that the collected data will produce accurate population estimates. In this context, sampling bias is a primary threat to a study's validity. If individuals who do not respond are a random sample of the population, then the estimates obtained from such a subsample are unbiased. However, as the percentage of nonrespondents increases, the assumption of unbiased estimation becomes increasingly tenuous. At this point an investigator has two choices: delete all subjects who have not provided data as part of the first data collection, or allow a respondent's point of entry to define his baseline measures for the study. No previous discussion of the latter option has been noted in the methods literature. Therefore the authors have termed this approach to baseline the "first record". Conditions under which the "first record" technique would be appropriate or inappropriate are discussed.     

Paradoxical facilitation of attention in healthy humans

Transcranial magnetic stimulation (TMS)-induced virtual lesions in healthy subjects can be used to test neurofunctional models of disease. The interhemispheric rivalry model of heminglect is well suited for such investigations, as simple predictions derived from clinical data can be tested without the caveats normally associated with lesion studies. One of these predictions is that release from contralateral inhibition should lead to increased parietal responsiveness, which, in turn, would enhance spatial attention. Here, we detail studies showing TMS-induced paradoxical functional facilitation of attention in healthy individuals and highlight their contribution to the understanding and treatment of neglect syndromes.     

The Collaborative Longitudinal Personality Disorders Study (CLPS): overview and implications

The Collaborative Longitudinal Personality Disorders Study (CLPS; Gunderson et al., 2000) was developed to fill gaps in our understanding of the nature, course, and impact of personality disorders (PDs). Here, we review published findings to date, discuss their implications for current conceptualizations of PDs, and raise questions that warrant future consideration. We have found that PDs are more stable than major depressive disorder, but that meaningful improvements are possible and not uncommon. We have confirmed also that PDs constitute a significant public health problem, with respect to associated functional impairment, extensive treatment utilization, negative prognostic impact on major depressive disorder, and suicide risk. At the same time, we have demonstrated that dimensional models of PDs have clinical validity that categories do not, especially greater temporal stability. Furthermore, dimensional personality traits appear to be the foundation of behaviors described by many PD criteria. Taken together, our results lead us to hypothesize that PDs may be reconceptualized as hybrids of stable personality traits and intermittently expressed symptomatic behaviors.     

Dispositional and task-specific social-cognitive determinants of physical effort perseverance

The authors performed 3 studies to investigate the effects of social-cognitive variables on physical effort perseverance. Linear hierarchical regressions indicated that task-specific variables and perceived ability or competence accounted for the majority of perseverance variance in all 3 studies. The strongest single predictors in this cluster of variables were perceived competence, confidence, and readiness to invest effort. Physical self-health and ability accounted for a lesser portion of effort perseverance variance, with self-presentation confidence being the major single predictor in this cluster. The goal orientation cluster accounted for the least amount of effort perseverance variance. Together with task-specific confidence and the readiness to invest effort, as well as determination and commitment and competence, the findings support the contention that task-specific efficacious beliefs to a large extent determine persistence and endurance behaviors.     

Effects of semantic cues on mathematical modeling: Evidence from word-problem solving and equation construction tasks

Mathematical solutions to textbook word problems are correlated with semantic relations between the objects described in the problem texts. In particular, division problems usually involve functionally related objects (e.g., tulips-vases) and rarely involve categorically related objects (e.g., tulips-daisies). We examined whether middle school, high school, and college students use object relations when they solve division word problems (WP) or perform the less familiar task of representing verbal statements with algebraic equations (EQ). Both tasks involved multiplicative comparison statements with either categorically or functionally related objects (e.g., "four times as many cupcakes [commuters] as brownies [automobiles]"). Object relations affected the frequency of correct solutions in the WP task but not in the EQ task. In the latter task, object relations did affect the structure of nonalgebraic equation errors. We argue that students use object relations as "semantic cues" when they engage in the sense-making activity of mathematical modeling.     

Sampling Bias and Other Methodological Threats to the Validity of Health Survey Research

Data from a longitudinal occupational health survey of professional fire fighters were used to explore the potential impact of two types of methodological bias: sample selection and reactivity. No significant differences on demographic variables were observed between the group who first responded after a within-study change in survey administration format (Delayed) and respondents who had completed surveys since the study's inception (Initial). However, statistically significant differences in the study's 26 outcome measures provided some evidence that between-group differences did exist and that an administration format type of response bias was also potentially present. The effect sizes associated with the 37 observed significant differences ranged from small to medium. These results provide a context for a reexamination of standard techniques for the identification and interpretation of survey research biases. Methods are suggested to strengthen tests for selection bias and to minimize the impact of response biases.