Bayesian and maximum likelihood estimation of hierarchical response time models

Hierarchical (or multilevel) statistical models have become increasingly popular in psychology in the last few years. In this article, we consider the application of multilevel modeling to the ex-Gaussian, a popular model of response times. We compare single-level and hierarchical methods for estimation of the parameters of ex-Gaussian distributions. In addition, for each approach, we compare maximum likelihood estimation with Bayesian estimation. A set of simulations and analyses of parameter recovery show that although all methods perform adequately well, hierarchical methods are better able to recover the parameters of the ex-Gaussian, by reducing variability in the recovered parameters. At each level, little overall difference was observed between the maximum likelihood and Bayesian methods.     

Godly play: an intervention for improving physical, emotional, and spiritual responses of chronically ill hospitalized children

An experimental two-group comparison pilot study of forty chronically ill hospitalized children was carried out at Wolfson Children's Hospital in Jacksonville, Florida. Three Godly Play interventions were given to participants in the experimental group. Children in the control group did not participate but received a fairy tale book as a control. The sample was evenly distributed with twenty (20) males and twenty (20) females. Ages ranged from six (6) to fifteen (15) years and all participants were chronically ill. Five (5) variables were studied. Of the five (5), three (3) showed significant differences before and after Godly Play: the Staic-Trait Anxiety Scale (p = .049), the Children's Depression Inventory (p = .011), and the McBride Spirituality Assessment (p = .033). A marginal difference in parent satisfaction with hospital care of children in the experimental and control groups was also determined (p = .058). Findings suggest that Godly Play had a significant effect on anxiety, depression, and spirituality of children and support the idea that the parents of children who participated in Godly Play were more satisfied with hospital care than those parents whose children did not engage in Godly Play.     

A Review of Research in the Social Scientific Study of Religion,Volume 15

Book reviewed in this article: Ralph L. Piedmont and David O. Moberg, Eds. (2005). Research in the Social Scientific Study of Religion, Volume 15.     

The relation between scores on the Buss–Perry Aggression Questionnaire and aggressive acts,impulsiveness, competitiveness,dominance, and sexual jealousy

This paper examines the relation of the four subscales (physical, verbal, anger and hostility) of the Buss–Perry Aggression Questionnaire (BPAQ) to act‐based aggression questionnaires (involving same‐sex or partners as opponents, and direct or indirect aggression) and evolutionarily based predictors of aggression, using an online student sample. All aggression measures were moderately correlated with one another. The BPAQ physical and verbal scales were most closely related to act‐based measures of direct aggression to a same‐sex other and the hostility scale to indirect aggression to a same‐sex other. The evolutionary variables were less closely related to the BPAQ than were the act‐based measures. Dominance and sexual jealousy were predictors of BPAQ physical, verbal and anger, and impulsiveness was a significant predictor of anger. Aggr. Behav. 32:1–10, 2006. © 2006 Wiley‐Liss, Inc.     

How do implementation intentions promote goal attainment? A test of component processes

Implementation intentions are plans that specify the when, where, and how of goal striving in advance, and have been shown to enhance rates of goal attainment compared to merely forming respective goal intentions. The present research investigated whether the accessibility of the specified situation (cue accessibility) and the strength of the association between the specified situation and the intended response (cue-response linkage) explain the impact of implementation intentions on goal achievement. Findings indicated that participants who planned how to undertake a verbal task better attained their goal compared to participants who did not form a plan. Crucially, implementation intention effects were mediated by the accessibility of the specified cue and by the strength of cue-response links. These findings support the idea that implementation intentions benefit performance because control of behavior is delegated to specified situational cues that initiate action automatically.     

The Effect of Disruptions During Counseling on Recall of Genetic Risk Information: The Case of Cystic Fibrosis

Genetic counseling is a communication process with two main functions: information provision and supportive counseling. The information transmission function may be compromised by disruptions that occur during counseling. At least two mediators are possible: (a) disruptions may interfere with memory by creating distractions and divided attention during encoding or (b) disruptions may degrade the flow of interaction which requires that participants engage in conversation repair rather than the task at hand. This study examined both alternatives in a group of parents (N=20 families, 40 individual parents) whose infant had received a newborn screening for cystic fibrosis (CF). Upon arrival at the hospital, each parent completed a questionnaire designed to assess his or her knowledge of CF. Their interaction with the genetic counselor was videotaped and coded for the presence of disruptions. Six weeks after the counseling, parents again completed the knowledge measure. The data showed a direct negative effect for disruptions during counseling on memory for CF-related risk information six weeks later. Disruptions also produced the anticipated effect on conversation, but counter to expectations, interruptions of conversation flow was positively associated with knowledge at time 2.     

‘Unwilling’ versus ‘unable’: capuchin monkeys’ (Cebus apella) understanding of human intentional action

A sensitivity to the intentions behind human action is a crucial developmental achievement in infants. Is this intention reading ability a unique and relatively recent product of human evolution and culture, or does this capacity instead have roots in our non‐human primate ancestors? Recent work by Call and colleagues (2004) lends credence to the latter hypothesis, providing evidence that chimpanzees are also sensitive to human intentions. Specifically, chimpanzees remained in a testing area longer and exhibited fewer frustration behaviors when an experimenter behaved as if he intended to give food but was unable to do so, than when the experimenter behaved as if he had no intention of giving food. The present research builds on and extends this paradigm, providing some of the first evidence of intention reading in a more distant primate relative, the capuchin monkey (Cebus apella). Like chimpanzees, capuchin monkeys distinguish between different goal‐directed acts, vacating an enclosure sooner when an experimenter acts unwilling to give food than when she acts unable to give food. Additionally, we found that this pattern is specific to animate action, and does not obtain when the same actions are performed by inanimate rods instead of human hands (for a similar logic, see Woodward, 1998 ). Taken together with the previous evidence, the present research suggests that our own intention reading is not a wholly unique aspect of the human species, but rather is shared broadly across the primate order.     

Abuse History, World Assumptions, and Religious Problem Solving

At a Christian university, 167 subjects completed questionnaires measuring worldview assumptions, religious problem solving, physical and emotional abuse, and subjects' beliefs about whether they had been "abused." Results indicated that worldview assumptions were not related to actual abuse histories. Instead, such assumptions were related to the subjects' beliefs that they had been abused. Subjects who believed that they had been abused had more negative views of the impersonal world, people, and themselves; they were also more likely to see events as random. Both actual abuse history and subjects' beliefs that they had been abused were related to religious problem-solving styles. Finally, problem-solving styles were related to various worldview assumptions. Results are discussed in terms of previous research on abuse and in the psychology of religion.     

Improving multiple behaviors for colorectal cancer prevention among african american church members.

The WATCH (Wellness for African Americans Through Churches) Project was a randomized trial comparing the effectiveness of 2 strategies to promote colorectal cancer preventive behaviors among 587 African American members of 12 rural North Carolina churches. Using a 2 X 2 factorial research design, the authors compared a tailored print and video (TPV) intervention, consisting of 4 individually tailored newsletters and targeted videotapes, with a lay health advisor (LHA) intervention. Results showed that the TPV intervention significantly improved (p <.05) fruit and vegetable consumption (0.6 servings) and recreational physical activity (2.5 metabolic task equivalents per hour) and, among those 50 and older (n = 287), achieved a 15% increase in fecal occult blood testing screening (p =.08). The LHA intervention did not prove effective, possibly because of suboptimal reach and diffusion.