The moderating influence of variability on belief revision

The variability of the information on which a belief was initially based should moderate the degree to which the belief is revised when new disconfirming information is received. Reasoning from everyday intuitions, psychological theories of concept representation, and a rational mathematical analysis, we inferred that as variability increased, resistance to disconfirming information would also increase. Participants’ judgments of the central tendencies of distributions of numerical information confirmed this prediction.     

Variability of response location on fixed-ratio and fixed-interval schedules of reinforcement

Variability of response location was studied in monkeys performing in a six-lever chamber. Fixed-ratio schedules, ranging from FR 1 to FR 300, generated a high degree of stereotypy of response location. In contrast, fixed-interval schedules of comparable reinforcement frequencies (0.06 to 4 minutes) generated much greater variability. These results failed to confirm any simple relationship between response variability and intermittence of reinforcement. Rather, variability seems to be determined by the particular characteristics of the reinforcement schedule.     

The emotionally disturbed child: Disturbed or disturbing

The notion that a child's behavior may be more disturbing than disturbed has been of interest to educators of behaviorally deviant children. Behavior indicative of deviance in children was studied with respect to the relative degree of disturbingness which each was judged to reflect. Four factor dimensions of disturbingness were identified and discussed with regard to future research and educational implications.The author wishes to thank Richard Gibson, John Salvia, and James Ysseldyke for their assistance in obtaining portions of the data represented here. A grateful acknowledgment is offered to Ron Eaves, Dave Herr, and John Salvia for their creative contributions.     

GPS: A Randomized Controlled Trial of Sexual Health Counseling for Gay and Bisexual Men Living With HIV

Gay, bisexual, and other men who have sex with men (GBM) continue to have high rates of HIV and sexually transmitted infections, including syphilis. GBM have therefore been identified by public health agencies as a high-priority population to reach with prevention initiatives. Despite the importance of mental health in preventing HIV and related infections, there is a shortage of credentialed mental health professionals to deliver behavioral Counseling interventions. The current study evaluated the efficacy of GPS, a community-based and peer-delivered sexual health promotion motivational interviewing–based intervention for HIV-positive GBM who engaged in condomless anal sex (CAS) in the past 2 months. GPS prevention counseling demonstrated a 43% relative reduction at 3-month follow-up in CAS with serodiscordant partners and significant reductions in sexual compulsivity. The study demonstrated that community-based counselors can administer an efficacious motivational interviewing program, and suggests a continued benefit of counseling methods to promote the sexual health of higher risk populations.     

Effects of medial preoptic hypothalamus anterior lesions on three kinds of behavior in the rat: Intermale aggressive,male-sexual,and mouse-killing behavior

Large lesions in the medial preoptic area-anterior hypothalamus (MPOA-AH) of adult male S3 rats reduce both intermale aggressive behavior and male sexual behavior considerably, but mouse-killing behavior is not impaired. Daily treatment with high doses of testosterone propionate for 21 days does not restore these behavioral effects. Smaller lesions in the same area affect male sexual and intermale aggressive behavior differently; in the frontal part of the MPOA-AH they affect aggressive behavior, while in a more caudal part they affect sexual behavior. Indications were found that lesions in specific parts of the stria terminalis and the medial forebrain bundle inhibit aggressive and sexual behavior.     

A Process Model of Causal Reasoning

How do we make causal judgments? Many studies have demonstrated that people are capable causal reasoners, achieving success on tasks from reasoning to categorization to interventions. However, less is known about the mental processes used to achieve such sophisticated judgments. We propose a new process model—the mutation sampler—that models causal judgments as based on a sample of possible states of the causal system generated using the Metropolis–Hastings sampling algorithm. Across a diverse array of tasks and conditions encompassing over 1,700 participants, we found that our model provided a consistently closer fit to participant judgments than standard causal graphical models. In particular, we found that the biases introduced by mutation sampling accounted for people's consistent, predictable errors that the normative model by definition could not. Moreover, using a novel experimental methodology, we found that those biases appeared in the samples that participants explicitly judged to be representative of a causal system. We conclude by advocating sampling methods as plausible process-level accounts of the computations specified by the causal graphical model framework and highlight opportunities for future research to identify not just what reasoners compute when drawing causal inferences, but also how they compute it.     

Dogmatic behavior among students: testing a new measure of dogmatism

The study tested the validity of a new measure of dogmatism by examining university students' evaluations of the Bible. Those who believed that every word in the Bible came directly from God and that the Bible is free of any error, contradiction, or inconsistency scored much higher on this dogmatism measure than students who thought otherwise. Such "true believers" then read the 4 highly varying Gospel accounts of the resurrection of Jesus. The most dogmatic of them still insisted there were no contradictions or inconsistencies in the Bible. The less dogmatic acknowledged that contradictions and inconsistencies exist. These results reinforce those of 4 earlier studies that indicated that the new measure of dogmatism has empirical validity.