Genetic and environmental influences on behavior: capturing all the interplay

Basic quantitative genetic models of human behavioral variation have made clear that individual differences in behavior cannot be understood without acknowledging the importance of genetic influences. Yet these basic models estimate average, population-level genetic and environmental influences, obscuring differences that might exist within the population and masking systematic transactions between specific genetic and environmental influences. This article discusses a newer, more sophisticated and powerful quantitative genetic model that articulates these transactions. Results from this model highlight the ways in which the gene- environment interaction and correlation are intertwined. They can be used to integrate findings from quantitative and molecular genetic studies and to understand the roles of genetic influences and social forces in manifested behaviors, even when DNA sequence variation is not relevant.     

Displayed emotions and witness credibility: a comparison of judgements by individuals and mock juries

Mock juries of 5–7 jurors viewed one of three video‐recorded versions of a rape victim's testimony, role‐played by a professional actress. The statement was given in a free‐recall manner with one of three kinds of emotions displayed, termed congruent, neutral and incongruent emotional expressions. The juries were requested to reach a decision on items in a short questionnaire, probing the perceived credibility of the witness and judgements of the probability of a guilty verdict. The jurors were then asked to complete the questionnaire a second time, individually and anonymously. A control group filled out the questionnaire individually without preceding jury deliberations. When participants judged credibility and guilt independently, without a preceding jury discussion, the displayed emotions strongly influenced the judgements. However, discussions in the context of the jury strongly attenuated the effect of displayed emotion, with judgements converging on the credibility of a neutral emotional expression as judged by independent participants, and the attenuating effect outlasted the jury‐situation. The results are consistent with research within social psychology showing that social stereotypes and prejudices are often neutralised by group discussions. Copyright © 2006 John Wiley & Sons, Ltd.     

Agentic and communal bias in socially desirable responding

This research was designed to investigate Paulhus' communion management (CM) and self‐deceptive enhancement (SDE), socially desirable responding (SDR) scales as measures of general SDR, communal bias and agentic bias. The CM and SDE scales, as well as the Schwartz values survey (SVS), were administered to four samples drawn from different cultures and subcultures (N = 900). Participants completed the questionnaires in ‘honest’ and ‘fake good’ conditions. Although conceptions of which values were desirable varied strongly between samples and instructional sets, the CM scale was consistently related to general SDR and to communal bias. In contrast, the SDE scale was only related to general SDR. Contrary to expectations, neither scale could identify participants who ‘faked good’ under normal instructions. Copyright © 2007 John Wiley & Sons, Ltd.     

Asymmetric discounting in intertemporal choice: a query-theory account

People are impatient and discount future rewards more when they are asked to delay consumption than when they are offered the chance to accelerate consumption. The three experiments reported here provide a process-level account for this asymmetry, with implications for designing decision environments that promote less impulsivity. In Experiment 1, a thought-listing procedure showed that people decompose discount valuation into two queries. Whether one considers delayed or accelerated receipt of a gift certificate influences the order in which memory is queried to support immediate versus delayed consumption, and the order of queries affects the relative number of patient versus impatient thoughts. Relative frequency and clustering of impatient thoughts predicts discounting and mediates the discounting asymmetry. Experiment 2 implicated query order causally: When participants listed reasons for immediate versus delayed consumption in the order used spontaneously in acceleration and delay decisions, the discounting asymmetry was replicated; reversing the order in which reasons were listed eliminated the asymmetry. The results of Experiment 3, which used an implicit-memory task, support a memory-interference account of the effect of query order.     

Infant rule learning facilitated by speech

Sequences of speech sounds play a central role in human cognitive life, and the principles that govern such sequences are crucial in determining the syntax and semantics of natural languages. Infants are capable of extracting both simple transitional probabilities and simple algebraic rules from sequences of speech, as demonstrated by studies using ABB grammars (la ta ta, gai mu mu, etc.). Here, we report a striking finding: Infants are better able to extract rules from sequences of nonspeech--such as sequences of musical tones, animal sounds, or varying timbres--if they first hear those rules instantiated in sequences of speech.     

Coenzyme Q10: a review of its promise as a neuroprotectant

Coenzyme Q10 (CoQ10) is a powerful antioxidant that buffers the potential adverse consequences of free radicals produced during oxidative phosphorylation in the inner mitochondrial membrane. Oxidative stress, resulting in glutathione loss and oxidative DNA and protein damage, has been implicated in many neurodegenerative disorders, including Alzheimer's disease, Parkinson's disease, and Huntington's disease. Experimental studies in animal models suggest that CoQ10 may protect against neuronal damage that is produced by ischemia, atherosclerosis and toxic injury. Though most have tended to be pilot studies, there are published preliminary clinical trials showing that CoQ10 may offer promise in many brain disorders. For example, a 16-month randomized, placebo-controlled pilot trial in 80 subjects with mild Parkinson's disease found significant benefits for oral CoQ10 1,200 mg/day to slow functional deterioration. However, to date, there are no published clinical trials of CoQ10 in Alzheimer's disease. Available data suggests that oral CoQ10 seems to be relatively safe and tolerated across the range of 300-2,400 mg/day. Randomized controlled trials are warranted to confirm CoQ10's safety and promise as a clinically effective neuroprotectant.     

Conditions for young infants' failure to perceive trajectory continuity

When viewing an event in which an object moves behind an occluder on part of its trajectory, 4-month-old infants perceive the trajectory as continuous only when time or distance out of sight is short. Little is known, however, about the conditions under which young infants perceive trajectories to be discontinuous. In the present studies we focus first on infants' perception of trajectories that change during a period of occlusion. Four-month-olds perceive discontinuity in trajectories that change in height or orientation while behind an occluder, and this is true even when a change in direction could be due to an invisible bouncing collision with a surface. Further experiments reveal that infants do not perceive diagonal linear trajectories as continuous across an occlusion unless the occluding and revealing edges are orthogonal to the path of movement. Implications for theories of perceptual and cognitive development are discussed.     

Dissociable effects of conscious emotion regulation strategies on explicit and implicit memory

The authors manipulated emotion regulation strategies at encoding and administered explicit and implicit memory tests. In Experiment 1, participants used reappraisal to enhance and decrease the personal relevance of unpleasant and neutral pictures. In Experiment 2, decrease cues were replaced with suppress cues that directed participants to inhibit emotion-expressive behavior. Across experiments, using reappraisal to enhance the personal relevance of pictures improved free recall. By contrast, attempting to suppress emotional displays tended to impair recall, especially compared to the enhance condition. Using reappraisal to decrease the personal relevance of pictures had different effects depending on picture type. Paired with unpleasant pictures, the decrease cue tended to improve recall. Paired with neutral stimuli, the decrease cue tended to impair recall. Emotion regulation did not affect perceptual priming. Results highlight dissociable effects of emotion regulation on explicit and implicit memory, as well as dissociations between regulation strategies with respect to explicit memory.     

Social Neuroscience: Progress and Implications for Mental Health

ABSTRACT— Social neuroscience is a new, interdisciplinary field devoted to understanding how biological systems implement social processes and behavior. Social neuroscience capitalizes on biological concepts and methods to inform and refine theories of social behavior, and it uses social and behavioral constructs and data to inform and refine theories of neural organization and function. We focus here on the progress and potential of social neuroscience in the area of mental health. Research in social neuroscience has grown dramatically in recent years. Among the most active areas of research we found are brain-imaging studies in normal children and adults; animal models of social behavior; studies of stroke patients; imaging studies of psychiatric patients; and research on social determinants of peripheral neural, neuroendocrine, and immunological processes. We also found that these areas of research are proceeding along largely independent trajectories. Our goals in this article are to review the development of this field, examine some currently promising approaches, identify obstacles and opportunities for future advances and integration, and consider how this research can inform work on the diagnosis and treatment of mental disorders.