A Cue Utilization Approach for Investigating Harvest Decisions in Commons Dilemmas

Hierarchical linear modeling (HLM) is introduced as a new tool for investigating decision making in commons dilemmas. University undergraduates ( N  = 171) managed a virtual fishery, with 2 computer-simulated fishers, over 60 seasons. Level 1 HLM analyses revealed that participants took significantly more fish during seasons when feedback suggested fish stocks, fish value, and fishing expenses were high; and when noncooperative and cooperative others had taken more fish and fewer fish, respectively, in the previous season. Level 2 analyses produced several cross-level interactions, indicating that participants' use of feedback information varied as a function of their social values and environmental attitudes.     

Psychosocial mediators of antiretroviral nonadherence in HIV-positive adults with substance use and mental health problems.

This study used data from 1,889 HIV-positive patients on antiretroviral (ARV) medications who participated in the HIV Cost and Services Utilization Study to investigate whether nonadherence to ARV medications among patients with mental health and substance use problems could be explained by difficulty getting and negative attitudes toward ARV medications, poor fit of the regimen with lifestyle, lack of instruction and cues for remembering the regimen from a health care provider, and poor support from others for taking ARV medications. Difficulty getting ARV medications and poor fit with lifestyle were significant mediators of nonadherence for patients with a probable psychiatric disorder. Difficulty getting medication was a mediator for heavy drinkers, and poor fit with lifestyle was a mediator for drug users who drank heavily. Further research is needed to identify and address the barriers to adherence in these populations.     

Visual pop-out in infants: Evidence for preattentive search in 3- and 4-month-olds

The present experiment tested for preattentive visual search in 3- and 4-month-old infants using stimulus features described by Treisman and Souther (1985) as producing visual “pop-out” effects in adults. Infants were presented with two visual arrays to the left and right of midline. One array comprised homogeneous elements, while the other had a discrepant element embedded in it. On the basis of previous research, we expected infants to fixate the array containing the embedded discrepant element. The pattern of fixation indicated detection of the embedded discrepant element for both age groups, but only with stimuli shown to elicit visual pop out in adults. This asymmetry in detection is consistent with the presence of preattentive visual search in infants as young as 3 months.     

FISH 3: A microworld for studying social dilemmas and resource management

A Java-based microworld environment for studying resource management is described. FISH 3 may be used in research or the classroom to investigate commons dilemmas and resource dilemmas. The program uses ocean fishing as its metaphor; participants (“fishers”) experience the metaphor through both graphics (“fish” may be seen in an ocean) and text (e.g., resource replenishment is translated as “spawning”). In either stand-alone or networked modes, either with all human fishers or a mixture of human and computer fishers, 15 parameters such as the number of resource units (fish), participants (fishers), and trials (seasons), payoff values, the rate and period of resource regeneration (spawning), harvesting greed by computer fishers, awareness of other harvesters’ actions, uncertainty in the amount of the resource, operating costs, and whether the resource is visible to harvesters may be varied.     

Bayesian estimation in the three-parameter logistic model

A joint Bayesian estimation procedure for the estimation of parameters in the three-parameter logistic model is developed in this paper. Procedures for specifying prior beliefs for the parameters are given. It is shown through simulation studies that the Bayesian procedure (i) ensures that the estimates stay in the parameter space, and (ii) produces better estimates than the joint maximum likelihood procedure as judged by such criteria as mean squared differences between estimates and true values. The research reported here was performed pursuant to Grant No. N0014-79-C-0039 with the Office of Naval Research. A related article by Robert J. Mislevy (1986) appeared when the present paper was in the printing stage.     

Prosperity: A new and foreign element in African Christianity

African Christianity is currently characterized by an evangelical revival which is in large measure funded and directed from California and the southern United States. Through these connections, North American Christianity is having considerable influence on a large segment of African Christianity. This article outlines one US development called ‘The Gospel of Prosperity’, and examines its spread to Africa. The author argues that this Gospel of Prosperity has particular socio-political effects; this form of Christianity provides no incentive to economic analysis and socio-political involvement, and thus accentuates further the differences between African Christianity and the liberation theology of Latin America.     

Causal uncertainty as a chronically accessible construct

Causal uncertainty refers to feelings that one may not understand the causes of events. A number of studies have shown that causal uncertainty has significant effects on people's processing of information and on important life outcomes. Weary and Edwards have postulated that causal uncertainty is, in part, a cognitive construct that can vary in its accessibility. This assumption has allowed for a variety of predictions to be made about the causes and consequences of causal uncertainty. However, this accessibility assumption has never been directly tested. To do this, in Study 1 an emotional Stroop procedure was used. Higher causal uncertainty was associated with longer latencies to name the color in which causal uncertainty‐related words were written compared to uncertainty‐irrelevant words. In Study 2, both manipulated and chronic causal uncertainty led to faster times to respond to causal uncertainty‐related stimuli in an attitude accessibility task. Both studies are consistent with the theoretically predicted chronic accessibility of causal uncertainty beliefs. Copyright © 2008 John Wiley & Sons, Ltd.     

Causal uncertainty and correction of judgments

We examined whether raising uncertainty about the causes of one’s judgments motivates correction. Specifically, we examined whether activating chronically accessible causal uncertainty (CU) beliefs with a conditional warning about possible bias enhances correction of weather judgments for tropical weather primes and of word frequency judgments for the availability bias. In two studies we showed that activating chronic beliefs led to careful correction of target judgments. Moreover, Study 2 revealed that chronically high-CU individuals who received a conditional warning felt more uncertain than did other participants, but that this uncertainty was suppressed somewhat by adjusting for the bias. Results are discussed in light of recent models of judgment correction (e.g., Wegener & Petty, 1997), and the causal uncertainty model (Weary & Edwards, 1996).