Schedule-induced defecation.

Excessive defecation, typically considered to be a concomitant of stress, was experimentally induced or eliminated under specific schedules of positive reinforcement of lever pressing by rats. The schedules were, by and large, those under which polydipsia is typically induced. In the first of three experiments, rats under fixed-interval 32-second schedules and variable interval 32-second schedules for food and water reinforcers defecated profusely, but not under fixed-interval one-second schedules or other small interval schedules. Somewhat higher rates of defecation were observed on variable interval 32-second schedules than on fixed-interval 32-second schedules. In a second experiment, fixed-ratio schedules were used, some of which resulted in responding such that reinforcement densities were similar to those on the interval schedules that induced defecation. Defecation was not systematically induced by these ratio schedules. In a third experiment, fixed-time schedules of food presentations were utilized. High rates of defecation were induced comparable to those induced by interval schedules of the same time parameter. No other behavior commonly termed "emotional" was observed in any of these experiments.     

Tacit coordination in monozygotic twins, dizygotic twins and virtual twins: Effects and implications of genetic relatedness

Game theorists have long been interested in why some partners are more successful at achieving mutual goals than others. The present study was conducted to determine if tacit coordination (non-negotiated consensus) varies as a function of genetic relatedness between social partners. The sample included 7–13-year-old monozygotic (MZ) twin pairs (n = 53), dizygotic (DZ) twin pairs (n = 85) and virtual twin (VT) pairs (n = 42; same-age unrelated siblings). Co-twin agreement on questions completed under individual and coordination conditions was compared across the three groups. MZ twins showed significantly greater overall agreement than DZ twins and VTs, using multiple criteria. The implications of these findings are considered with reference to behavioral-genetic and evolutionary theories of behavior.     

Initial psychometric properties of the experiences questionnaire: validation of a self-report measure of decentering

Decentering is defined as the ability to observe one's thoughts and feelings as temporary, objective events in the mind, as opposed to reflections of the self that are necessarily true. The Experiences Questionnaire (EQ) was designed to measure both decentering and rumination but has not been empirically validated. The current study investigated the factor structure of the EQ in both undergraduate and clinical populations. A single, unifactorial decentering construct emerged using 2 undergraduate samples. The convergent and discriminant validity of this decentering factor was demonstrated in negative relationships with measures of depression symptoms, depressive rumination, experiential avoidance, and emotion regulation. Finally, the factor structure of the EQ was replicated in a clinical sample of individuals in remission from depression, and the decentering factor evidenced a negative relationship to concurrent levels of depression symptoms. Findings from this series of studies offer initial support for the EQ as a measure of decentering.     

The Frazerian roots of contemporary theories of religion and violence

The association of religion with violence rather than with peace long antedates 9/11. Among theorists of religion, the association goes back at least to J.G. Frazer, author of the classic The Golden Bough (first ed. 1890). Contemporary theorists who tie religion to violence are beholden to Frazer, even when they spurn any dependence. At the same time the function of religious violence for contemporary theorists has shifted from control over the physical world to control over the social world. That shift typifies the overall shift from a nineteenth-century approach to religion to a twentieth-century one. This article considers two of the most prominent contemporary theorists who connect religion to violence: René Girard and Walter Burkert. How they at once depend on Frazer and break with him is the subject of this article.     

Age-dependent glutamate induction of synaptic plasticity in cultured hippocampal neurons

A common denominator for the induction of morphological and functional plasticity in cultured hippocampal neurons involves the activation of excitatory synapses. We now demonstrate massive morphological plasticity in mature cultured hippocampal neurons caused by a brief exposure to glutamate. This plasticity involves a slow, 70%-80% increase in spine cross-section area associated with a significant reduction in the width of dendrites. These changes are age dependent and expressed only in cells >18 d in vitro (DIV). Activation of both NMDARs and AMPARs as well as a sustained rise of internal calcium levels are necessary for induction of this plasticity. On the other hand, blockade of network activity or mGluRs does not abolish the observed morphological plasticity. Electrophysiologically, a brief exposure to glutamate induces an increase in the magnitude of EPSCs evoked between pairs of neurons, as well as in mEPSC frequency and amplitude, in mature but not young cultures. These results demonstrate an age-dependent, rapid and robust morphological and functional change in cultured central neurons that may contribute to their ability to express long term synaptic plasticity.     

The "don't ask, don't tell" policy and military performance

This paper is a response to Schumm's 2004 critique of Belkin's 2003 article, dealing with the "Don't Ask, Don't Tell" policy in the U.S. military. Schumm's critique specified four reasons for continuing to exclude homosexuals from military service: military effectiveness, sexual asymmetries, Christian soldiers' dilemma of "living a lie" and skewed opinions of policy makers and military elites. Each of these categories is analyzed and discussed.     

Coherent Odds and Subjective Probability

A well-known Dutch book, due to de Finetti, shows how violations of the additivity law of probability theory (Pr(A∪B)=Pr(A)+Pr(B)−Pr(A∩B)) open the door to a sequence of bets leading to a sure loss. In this paper we show that in a market environment, when bookies act strategically, it may well be optimal for them to post incoherent (nonadditive) odds. This is true even when the bookie's own preferences are expected utility, provided she plays against at least two nonexpected utility bettors.