Rationality and bounded information in repeated games, with application to the iterated Prisoner's Dilemma

Actions in a repeated game can in principle depend on all previous outcomes. Given this vast policy space, human players may often be forced to use heuristics that base actions on incomplete information, such as the outcomes of only the most recent trials. Here it is proven that such bounded rationality is often fully rational, in that the optimal policy based on some limited information about the game's history will be universally optimal (i.e., within the full policy space), provided that one's opponents are restricted to using this same information. It is then shown how this result allows explicit calculation of subgame-perfect equilibria (SPEs) for any repeated or stochastic game. The technique is applied to the iterated Prisoner's Dilemma for the case of 1-back memory. Two classes of SPEs are derived, which exhibit varying degrees of (individually rational) cooperation as a result of repeated interaction.     

A Comparison of Constant Time Delay and Simultaneous Prompting Within Embedded Instruction in General Education Classes with Students with Moderate to Severe Disabilities

An adapted alternating treatment design was used to measure the effectiveness of constant time delay and simultaneous prompting procedures within an embedded instruction format on the acquisition of academic skills. Four middle school students with moderate to severe disabilities and the paraprofessionals who supported these students in their general education classes participated in the study. The results of the study indicated that both procedures were effective in promoting the acquisition of the target skills. However, the constant time delay procedure was more effective for two of the students and the simultaneous prompting procedure was more effective for the remaining students. Results are discussed in terms of future research and implications for supporting the inclusion of students with moderate and severe disabilities in general education classes.     

Personality Traits Predict the Developmental Course of Externalizing: A Four‐Wave Longitudinal Study Spanning Age 17 to Age 29

The objective of the present study was to determine whether and how personality predicts the developmental course of externalizing problems, including antisocial behavior and substance dependence. In a large, population‐based longitudinal study (N = 1,252), the 11 personality traits assessed by the Multidimensional Personality Questionnaire were measured at age 17, and DSM diagnoses of adult antisocial behavior, alcohol dependence, and drug dependence were obtained at ages 17, 20, 24, and 29. We fit a quadratic multiple indicator latent growth model where the three diagnoses loaded onto an externalizing factor. This model fit the data well, and externalizing increased until it started to decline at age 24. High aggression and low control were the most significant predictors of the development of externalizing, with aggression playing a significant role in the development of externalizing across the 12‐year time span, and control predicting the development from age 17 to 24. The findings highlight the importance of considering the developmental course of externalizing in the context of personality and suggest that the specific personality traits of aggression and control might be targeted in externalizing prevention and intervention programs.     

Working memory and behavioral inhibition in boys with ADHD: An experimental examination of competing models

Working memory (WM) and behavioral inhibition impairments have garnered significant attention as candidate core features, endophenotypes, and/or associated neurocognitive deficits of attention-deficit/hyperactivity disorder (ADHD). The relationship between ADHD-related WM and inhibition deficits remains relatively unclear, however, with inferences about the constructs’ directional relationship stemming predominantly from correlational research. The current study utilized a dual-task paradigm to experimentally examine the relationship between ADHD-related WM and behavioral inhibition deficits. A total of 31 boys (15 ADHD and 16 typically developing [TD]) aged 8–12 years completed WM (1-back and 2-back), behavioral inhibition (stop-signal task [SST]), and dual-condition (1-back/SST and 2-back/SST) experimental tasks. Children with ADHD exhibited significant, large-magnitude WM deficits for the 1-back condition but were not significantly different from children in the TD group for the 2-back, 1-back/SST, and 2-back/SST conditions. Children with ADHD also exhibited significant inhibition deficits for the SST, 1-back/SST, and 2-back/SST conditions, but the within-group effect was not significant. The findings suggest that ADHD-related stop-signal demands are upstream, or compete for, resources involved in controlled-focused attention and/or other central executive (CE), WM processes.     

Parenting Intervention to Reduce Attention and Behavior Difficulties in Preschoolers: A CUIDAR Evaluation Study

In this study, we evaluated CUIDAR, a program that provides community-based 10-week parent training to reduce attention and behavior problems in preschool children. We recruited 154 predominantly low-income and Latino preschoolers and their parents to participate in this evaluation study. We collected data prior to and immediately following intervention and one year later. At the time of follow-up, we also recruited 15 parents who had initially enrolled, but never participated in the program to serve as a comparison group for a limited set of analyses. From pre to post intervention, we observed significant, positive changes in eight out of ten measured parenting behaviors. From pre intervention to follow-up, improvements in the use of transitional statements and planning ahead were significant. Children’s SDQ Total Difficulties scores significantly decreased from pre to post intervention (d = .36), and we observed significant, positive changes in all SDQ subscales. From pre intervention to follow-up, children’s SDQ Total Difficulties scores significantly decreased (d = .71) and all SDQ subscales reflected significant, positive changes. We observed no significant differences in reported barriers to participation between parents who participated in the program and those who enrolled, but never participated. Intervention gains were moderated by several factors, including history of out-of-home care and family structure. Our results should be interpreted cautiously because not all analyses included a comparison group, and a randomized trial of CUIDAR effectiveness is still needed.     

Virtues,Skills, and Right Action

According to Rosalind Hursthouse’s virtue based account of right action, an act is right if it is what a fully virtuous person would do in that situation. Robert Johnson has criticized the account on the grounds that the actions a non-virtuous person should take are often uncharacteristic of the virtuous person, and thus Hursthouse’s account of right action is too narrow. The non-virtuous need to take steps to improve themselves morally, and the fully virtuous person need not take these steps. So Johnson argues that any virtue based account of right action will have to find a way to ground a moral obligation to improve oneself. This paper argues that there is an account of virtue that can offer a partial solution to Johnson’s challenge, an account where virtue is a type of practical skill and in which the virtuous person is seen as having expertise. The paper references the account of skill acquisition developed by Hubert and Stuart Dreyfus. Their research demonstrates that novices in a skill have to employ different strategies to act well than the strategies used by the experts, and so the ‘virtue as skill’ thesis provides support for Johnson’s claim that the actions of the non-virtuous will differ from the virtuous. On the other hand, their research suggests that there is no separating the commitment to improve yourself from the possession of expertise, and so the ‘virtue as skill’ thesis has the resources for grounding the obligation to improve oneself in an account of virtue.     

Self‐reported psychopathology in a convicted serial killer

The following paper presents a case study of a convicted serial murderer. Through data from personal correspondence, police reports, a true crime novel, witness statements, medical examiner reports, court appeals, and crime scene reports from the actual murder cases, and most important, a series of psychological self‐report measures, a case study was developed. Included in the psychological measures were tests of general psychopathology, specific tests of psychopathy, anger and aggression scales, and sociological measures related to family, individual, situational, and community risk factors, as well as previous criminal behaviour, including weapon and drug use. The results of these various measures are incorporated into the life history and criminal activity of the individual. The purpose of this research was to develop a more complete psychological report of a serial killer than any other previously reported. Copyright © 2010 John Wiley & Sons, Ltd.     

Dietary restraint moderates genetic risk for binge eating

Dietary restraint is a prospective risk factor for the development of binge eating and bulimia nervosa. Although many women engage in dietary restraint, relatively few develop binge eating. Dietary restraint may increase susceptibility for binge eating only in individuals who are at genetic risk. Specifically, dietary restraint may be a behavioral exposure factor that activates genetic predispositions for binge eating. We investigated this possibility in 1,678 young adolescent and adult same-sex female twins from the Minnesota Twin Family Study and the Michigan State University Twin Registry. Twin moderation models were used to examine whether levels of dietary restraint moderate genetic and environmental influences on binge eating. Results indicated that genetic and nonshared environmental factors for binge eating increased at higher levels of dietary restraint. These effects were present after controlling for age, body mass index, and genetic and environmental overlap among dietary restraint and binge eating. Results suggest that dietary restraint may be most important for individuals at genetic risk for binge eating and that the combination of these factors could enhance individual differences in risk for binge eating.     

Testing the role of adolescent sexual initiation in later-life sexual risk behavior: a longitudinal twin design

The consistent association between adolescent sexual initiation (ASI) and risky adult sexual behavior (RASB) has generally been assumed to indicate that ASI has a causal effect on RASB; consequently, it is assumed that delaying ASI will reduce RASB. Yet the ASI-RASB association might be better accounted for by some third variable. We evaluated the causal role of ASI (initiation of oral, anal, or vaginal sex at or before age 16) in influencing RASB in a longitudinal sample of 2,173 twins (followed from ages 11 to 24 or from ages 17 to 29) using two methods: the discordant-twin design and the propensity-score design. The former controlled for unmeasured genetic and shared environmental factors, and the latter controlled for measured nonshared environmental factors. We replicated the link between ASI and RASB reported in previous research, but results from the discordant-twin and propensity-score analyses suggested that this association is better explained by common genetic or environmental risk factors than as a causal effect. These findings suggest that preventing ASI is unlikely to reduce RASB.