Effects of Acute Stress or Centrally Injected Interleukin-1beta on Neuropeptide Expression in the Immune System

Acute stress stimulates the expression and release of corticotropin-releasing hormone (CRH) and arginine vasopressin (AVP) from the hypothalamus, and the pro-opiomelanocortin products beta-endorphin and ACTH from the anterior pituitary. These neuropeptides are also expressed in immune tissues, and it has been proposed that they may modulate immune responses to stress through paracrine mechanisms. We subjected rats to restraint stress or central injection of interleukin (IL)-1beta to determine whether these acute stimuli can alter the expression of neuropeptides in the spleen and thymus. Restraint stress significantly increased the contents of all these neuropeptides in thymic, but not splenic, extracts. A single icv injection of IL-1beta increased contents of CRH, AVP, ACTH and beta-endorphin in the spleens of both sham-operated and adrenalectomised (ADX) rats. IL-1beta increased thymic contents of CRH and ACTH in sham-operated rats but these increases were not observed in ADX rats. These results suggest that the effects of IL-1beta on neuropeptide expression in the spleen are independent of glucocorticoids, whereas IL-1beta stimulation of neuropeptide expression in the thymus is dependent on circulating glucocorticoids. There were significant correlations between increases in CRH, ACTH and beta-endorphin in the spleen, and between CRH and ACTH in the thymus, consistent with the suggestion that IL-1beta-induced increases in ACTH and beta-endorphin may be mediated through CRH. These results provide evidence that stressors can directly influence neuropeptide expression in immune tissues. Thus stress may influence immune functions through paracrine mechanisms involving locally synthesised neuropeptides as well as through activation of the hypothalamo-pituitary-adrenal axis.     

Undermining the Zeigarnik effect: Another hidden cost of reward

Forty college students participated in a study ostensibly designed to obtain measures of the hemispheric activity while they worked on a spatial reasoning task. In fact, our true interest was in determining whether subjects would return to the spatial reasoning task once the hemispheric recordings were completed. Subjects would normally be expected to return to the task by virtue of the Zeigarnik effect because no subject completed the task during the “hemispheric recording” phase. The manipulation involved telling one group of subjects that they would be paid $1.50 for participating in the study (expected reward group). The remainder of the subjects were not led to expect the reward (unexpected reward group). The result was that 86% of the unexpected reward subjects but only 58% of the expected reward subjects (p < .05) manifested the Zeigarnik effect. This differential tendency to return to the task was further reflected in time differences. The average unexpected reward subject spent 3 min 48 sec of a five-minute free-choice period at the task, whereas the average expected reward subject spent only 2 min 20 sec (p < .05). Reward expectancy, therefore, led to an undermining of the Zeigarnik effect. This observation supports Condry's prediction that rewarding performance at a task can lead to premature task disengagement.     

Reactionary Deconversion from Mormonism: Polarization of Ideological and Behavioral Religiosity Among Active and Former Mormons

In contrast to a growing body of literature examining the experiences and trends of those who leave their faith tradition—particularly among Christian denominations—relatively little is known about those who specifically disaffiliate from Mormonism, although some evidence suggests that former Mormons may be especially likely to embrace secularity or irreligion rather than other religious beliefs and practices. Pursuant to empirically investigating this reactionary dynamic, the current study compared the relative religiosity and secularity of an online sample of active Mormons (n?=?194) and former Mormons (n?=?109) using the Abbreviated Religiousness Measure (ARM), an updated questionnaire of multidimensional religiosity. Results supported the ARM’s improved psychometrics and its hypothesized three-factor structure with both subsamples. Additionally, multivariate and univariate results indicated that active and former Mormon participants from our sample, significantly polarized in their self-reported level of religious beliefs, rituals, and influence on daily behaviors, with active Mormon reporting high religiosity and former Mormons reporting low religiosity or high secularity. Although these results comport with reactionary deconversion dynamics found in other high cost religions, limits to generalizability are discussed. Reasons for and implications of this reactionary phenomenon are also posited.     

Expectations and emotions of Olympic athletes

In an often-cited study about counterfactuals, Medvec, Madey, and Gilovich (1995) found that bronze medalists appeared happier than silver medalists in television coverage of the 1992 Summer Olympics. Medvec et al. argued that bronze medalists compared themselves to 4th place finishers, whereas silver medalists compared themselves to gold medalists. These counterfactuals were the most salient because they were either qualitatively different (gold vs. silver) or categorically different (medal vs. no medal) from what actually occurred. Drawing on archival data and experimental studies, we show that Olympic athletes (among others) are more likely to make counterfactual comparisons based on their prior expectations, consistent with decision affect theory. Silver medalists are more likely to be disappointed because their personal expectations are higher than those of bronze medalists. We provide a test between expectancy-based versus category-based processing and discuss circumstances that trigger each type of processing.     

The distracting effect of material reward: An alternative explanation for the superior performance of reward groups in probability learning

To determine whether the distraction effect associated with material rewards in discrimination learning can account for the superior performance of reward groups in probability learning, the performance of 144 school children (preschool, second, and fifth grades) on a two-choice successive discrimination task was compared under three reinforcement conditions (material reward, marker, and knowledge of results). The two events in the task had different frequencies of occurrence, as in probability learning, yet they appeared in a constant order to make 100% payoff possible. The subjects in the reward and marker groups learned the task more slowly, and the nonlearners among them used stereotyped alternation patterns to a greater degree than subjects in the knowledge-of-results condition. These findings suggest that a distracting effect of material reward is present in probability learning and may explain the superior performance of reward groups typically found in probability learning studies.     

Downward comparison, prejudice, and evaluations of others: effects of self-esteem and threat

In two studies, we explored the effects of trait self-esteem and threats to the self-concept on evaluations of others. In Study 1, subjects high, moderate, and low in self-esteem received either success, failure, or no feedback on a test and later evaluated three pairs of targets: in-groups and out-groups based on a minimal intergroup manipulation, those who scored above average and those who scored below average on the test, and themselves and the average college student. Study 2 explored the effects of self-esteem and threat on in-group favoritism in a real-world setting, campus sororities. Together, the results of these studies indicate that individuals high in self-esteem, but not those low in self-esteem, respond to threats to the self-concept by derogating out-groups relative to the in-group when the group boundaries have evaluative implications.     

Subjective probabilities and moral judgments

The two experiments reported here examined the relationship between subjective probability estimates and moral judgments (credit and blame assignment, trait attributions, and behavior evaluations). Subjects read about situations that varied in outcome valence (moral or immoral); in addition, the nature of situational demands (Experiment 1) or behavior frequency (Experiment 2) was varied. In the first experiment, subjective probabilities were related to judgments of immoral behaviors (but not moral behaviors), whereas the situational demands only had an impact on judgments of moral behaviors. Experiment 2 included a wider range of behavioral situations, and the probability estimates and moral judgments were assessed independently. In contrast to the first experiment, subjective probabilities were related to trait and behavior ratings of both moral and immoral acts. Consistent with the first experiment, however, subjective probabilities predicted blame but not credit. Across both studies, the prior expectancies were more strongly related to evaluations of immoral acts than moral acts. Implications for understanding the determinants of judgments of moral and immoral acts are discussed.