Behavior Genetics: What's New? What's Next?

What's new in behavior genetics? With widespread acceptance that nearly all behavioral variation reflects some genetic influence, current studies are investigating developmental changes in the nature and magnitude of genetic and environmental effects, the extent to which different behaviors are influenced by common genes, and different forms of gene-environment correlation and interaction. New designs, focused on assessment of unrelated children in the same households or neighborhood environments, and use of measured environmental variables within genetically informative designs, are yielding more incisive evidence of common environmental effects on behavior. What will be next? Behavior genetic techniques and analyses will be used to inform efforts to find genes altering susceptibility for disorder and dispositional genes affecting behavioral variation. The developing integration of behavioral and molecular genetics will identify genes influencing specific behavioral variation and enhance understanding of how they do so. Psychologists will play a pivotal role in communicating that understanding to the public and in facilitating consideration of the inevitable ethical issues then to be confronted.     

Family Interaction Patterns as Predictors of Vocational Identity and Career Decision-Making Self-Efficacy

The present study explored the relations of perceived family-of-origin interaction patterns (e.g., quality of family relationships, family-supported goal orientations, and degree of control and organization in the family) to vocational identity and career decision-making self-efficacy. A sample of 210 college students completed family-of-origin and vocational self-report measures. Using standard multiple regression analyses, significant variance was accounted for in vocational identity scores by achievement orientation in the family. Significant variance in career decision-making self-efficacy scores was accounted for by a number of family variables including achievement, intellectual-cultural, and moral-religious emphasis orientations and degree of family conflict and expressiveness. The findings suggest that family-of-origin interaction patterns may play small, yet significant roles in the formulation of clear and stable career goals and the promotion of self-confidence in regard to completing career planning activities. These findings warrant further empirical examination of the family systems approach to young adult career development.     

Measured Gene–Environment Interactions and Mechanisms Promoting Resilient Development

ABSTRACT— Childhood maltreatment elevates risk for antisocial behavior, depression, and other problems over the life span, but a subset of maltreated individuals avoids maladaptive development and shows resilience. Resilience reflects a dynamic confluence of factors that promotes positive adaptation despite exposure to adverse experiences. Recent replicated findings of gene–environment interactions (abbreviated G × E) involving maltreatment have identified two genes, monoamine oxidase A ( MAOA ) and serotonin transporter ( 5-HTT ), that moderate the association between childhood maltreatment and psychopathology. Accordingly, G × E raise new questions about potential biological mechanisms by which some individuals are able to cope adaptively and function relatively well despite experiencing early adversity. We summarize advances toward greater specification of G × E mechanisms, including genetic and environmental moderation of G × E effects and imaging genomics that provide clues regarding resilience processes in development.     

Genes in Context: Gene–Environment Interplay and the Origins of Individual Differences in Behavior

ABSTRACT— Interactions between genes and the environment are a critical feature of development. Insights into the dynamic interplay between these factors have come from laboratory studies exploring experience-dependent changes in gene function, which illustrate the importance of environmental factors in determining activity of the genome. These studies have implications for our understanding of the origins of individual differences in behavior and may provide new ways of thinking about the transmission of traits across generations. Here we will highlight how these new findings illustrate the importance of putting genes in context.     

Patterns of Conflict Interaction in Mother–Toddler Dyads: Differences Between Depressed and Non-depressed Mothers

We examined the differences in conflict interaction between depressed mothers and their toddler and non-depressed dyads and whether these differences mediated the association of maternal depression with compromised child socioemotional development. Mother/child interaction was videotaped during a teaching task and during a free play task as part of a home visit when the target child was between 16 and 18 months old. Each turn of every conflict was coded for behavior and affect of each member of the dyad. Interaction data were summarized to calculate the number of conflict turns, the rate of conflict, and the proportion of mother-initiated versus child-initiated conflicts per dyad. Sequential analysis was used to estimate the probability of specific maternal responses to specific child behaviors. Bivariate comparisons indicated that depressed dyads experienced higher rates of conflict, especially during the teaching task, and that depressed mothers were more likely to respond destructively to child oppositional behavior. Results of multivariate linear regression indicated that the higher probability of destructive response mediated the association of maternal depression with lower quality of mother–child attachment. These findings have implications for the development of interventions to support mothers in dealing with the conflicts that are so common during the second year of a child’s life.     

Habituation in Aplysia: The Cheshire Cat of neurobiology

The marine snail, Aplysia californica, is a valuable model system for cell biological studies of learning and memory. Aplysia exhibits a reflexive withdrawal of its gill and siphon in response to weak or moderate tactile stimulation of its skin. Repeated tactile stimulation causes this defensive withdrawal reflex to habituate. Both short-term habituation, lasting <30 min, and long-term habituation, which can last >24 h, have been reported in Aplysia. Habituation of the withdrawal reflex correlates with, and is in part due to, depression of transmission at the monosynaptic connection between mechanoreceptive sensory neurons and motor neurons within the abdominal ganglion. Habituation-related short-term depression of the sensorimotor synapse appears to be due exclusively to presynaptic changes. However, changes within the sensory neuron, by themselves, do not account for more persistent depression of the sensorimotor synapse. Recent behavioral work suggests that long-term habituation in Aplysia critically involves postsynaptic processes, specifically, activation of AMPA- and NMDA-type receptors. In addition, long-term habituation requires activity of protein phosphatases, including protein phosphatases 1, 2A, and 2B, as well as activity of voltage-dependent Ca²⁺ channels. Cellular work has succeeded in demonstrating long-term, homosynaptic depression (LTD) of the sensorimotor synapse in dissociated cell culture and, more recently, LTD of the glutamate response of isolated motor neurons in culture (“hemisynaptic” LTD). These in vitro forms of LTD have mechanistic parallels to long-term habituation. In particular, homosynaptic LTD of the sensorimotor synapse requires elevated intracellular Ca²⁺ within the motor neuron, and hemisynaptic LTD requires activity of AMPA- and NMDA-type receptors. In addition, activation of group I and II metabotropic glutamate receptors (mGluRs) can induce hemisynaptic LTD. The demonstration of LTD in vitro opens up a promising new avenue for attempts to relate long-term habituation to cellular changes within the nervous system of Aplysia.     

Psychosocial environment and affective outcomes in technology-rich classrooms: testing a causal model

Research investigated classroom environment antecedent variables and student affective outcomes in Australian high schools. The Technology-Rich Outcomes-Focused Learning Environment Inventory (TROFLEI) was used to assess 10 classroom environment dimensions: student cohesiveness, teacher support, involvement, investigation, task orientation, cooperation, equity, differentiation, computer usage and young adult ethos. A sample of 4,146 high school students from Western Australia and Tasmania responded to the TROFLEI and three student outcome measures: attitude to the subject, attitude to computer use and academic efficacy. Confirmatory factor analysis using LISREL supported the 10 scale a priori structure of the instrument. Structural equation modeling using LISREL was used to test a postulated model involving antecedent variables, classroom environment and outcomes. The modeling indicated that: improving classroom environment has the potential to improve student outcomes, antecedents did not have any significant direct effect on outcomes, and academic efficacy mediated the effect of several classroom environment dimensions on attitude to subject and attitude to computer use.

When the wheels on the bus go round: social interactions on the school bus

Children’s social interactions are often dependent upon the setting or context in which they occur. The current study explored the school bus as a unique context for social interaction. One hundred and fifty-seven elementary school students (78 males and 79 females), in grades 3, 4, and 5, completed a questionnaire concerning the rate and types of prosocial and aggressive behaviors that occur on the school bus ride. Overall, findings indicated that students were prosocial more often on the school bus than they were aggressive. Regarding the types of social behaviors, differences found in the current study were distinctive. Participants mentioned non-traditionally studied prosocial behaviors (e.g., companionship and benevolence) more often than traditionally studied behaviors (e.g., sharing and helping). In addition, participants mentioned physical aggression more often among their female peers than among their male peers. This study reveals the importance of context in understanding children’s social behaviors. It is concluded that the present results have important implications for the school bus context and for future research on children’s social interactions.

Evidence against integration of spatial maps in humans: generality across real and virtual environments

A real-world open-field search task was implemented with humans as an analogue of Blaisdell and Cook’s (Anim Cogn 8:7–16, 2005) pigeon foraging task and Sturz, Bodily, and Katz’s (Anim Cogn 9:207–217, 2006) human virtual foraging task to 1) determine whether humans were capable of integrating independently learned spatial maps and 2) make explicit comparisons of mechanisms used by humans to navigate real and virtual environments. Participants searched for a hidden goal located in one of 16 bins arranged in a 4 × 4 grid. In Phase 1, the goal was hidden between two landmarks (blue T and red L). In Phase 2, the goal was hidden to the left and in front of a single landmark (blue T). Following training, goal-absent trials were conducted in which the red L from Phase 1 was presented alone. Bin choices during goal-absent trials assessed participants’ strategies: association (from Phase 1), generalization (from Phase 2), or integration (combination of Phase 1 and 2). Results were inconsistent with those obtained with pigeons but were consistent with those obtained with humans in a virtual environment. Specifically, during testing, participants did not integrate independently learned spatial maps but used a generalization strategy followed by a shift in search behavior away from the test landmark. These results were confirmed by a control condition in which a novel landmark was presented during testing. Results are consistent with the bulk of recent findings suggesting the use of alternative navigational strategies to cognitive mapping. Results also add to a growing body of literature suggesting that virtual environment approaches to the study of spatial learning and memory have external validity and that spatial mechanisms used by human participants in navigating virtual environments are similar to those used in navigating real-world environments.     

言语情绪韵律加工的时间进程

有关情绪韵律加工的时间进程,现在的研究采用ERP技术在词汇和句子水平上进行探讨：在词汇水平,韵律情绪信息和语义情绪信息都存在自动加工,前者可在300ms内得以识别,受到性别、注意等因素的调节;在句子水平,语义情绪加工可能“制约”韵律情绪加工,二者具有交互作用。未来研究应进一步探索情绪韵律加工的时间进程以及与其他信息加工的相互时间关系等。