Hilbert's epsilon as an operator of indefinite committed choice

Hilbert and Bernays avoided overspecification of Hilbert's ε-operator. They axiomatized only what was relevant for their proof-theoretic investigations. Semantically, this left the ε-operator underspecified. After briefly reviewing the literature on semantics of Hilbert's epsilon operator, we propose a new semantics with the following features: We avoid overspecification (such as right-uniqueness), but admit indefinite choice, committed choice, and classical logics. Moreover, our semantics for the ε simplifies proof search and is natural in the sense that it mirrors some cases of referential interpretation of indefinite articles in natural language.     

Perceptions of self and other in the prisoner's dilemma: outcome bias and evidential reasoning

In the prisoner's dilemma, self-interest clashes with collective interest. The way players resolve this conflict affects how others view them. Cooperators are seen as more moral than defectors, and, when there is no information about the other player's choice, cooperators and defectors are seen as equally competent. However, players who are defected against are seen as less competent, especially if they themselves cooperated (Experiments 1 and 2). Similarly, cooperators see themselves as more moral, but not as less competent, than defectors do (Experiments 3). Independent of concerns about reputation and self-image maintenance, evidential reasoning contributes to cooperative behavior. Players who project their own attitudes onto others are more likely to cooperate (Experiments 3). Compared with classic game theory, a theory of reputational concerns and evidential reasoning is better equipped to explain empirical patterns of choice behavior in social dilemmas.     

On the predictive validity of indirect attitude measures: Prediction of consumer choice behavior on the basis of affective priming in the picture-picture naming task

Recent studies have revealed that robust and replicable affective priming of naming responses can be obtained when pictures are used as primes and targets. The aim of the present research was to examine the predictive validity of affective priming effects that are obtained with the picture-picture naming task. In two studies that were modeled after [Karpinski, A., & Hilton, J. L. (2001). Attitudes and the Implicit Association Test. Journal of Personality and Social Psychology, 81, 774-778], we observed that individual difference scores that are obtained with the naming task exhibit good predictive validity. Both practical and theoretical implications of this finding are discussed.     

Unconscious priming according to multiple S-R rules

The present study investigated if unconscious primes can be processed according to different stimulus-response (S-R) rules simultaneously. Participants performed two different S-R rules, such as judging a digit as smaller or larger than five and judging a letter as vowel or consonant. These S-R rules were administered in random order and announced by a previously presented cue. Each target stimulus was preceded by subliminal primes which afforded a different or an identical response according to either the currently irrelevant or currently relevant S-R rule. In three experiments, we consistently found priming effects according to currently irrelevant S-R rules, even when primes for the relevant and irrelevant S-R rules were presented simultaneously. Thus, unconscious stimuli have the power to activate responses according to currently required and currently not required S-R rules concurrently. The results are in line with response activation accounts of subliminal priming and suggest that at least two routes may gain access on response processes simultaneously.     

Externalizing symptoms among children of alcoholic parents: Entry points for an antisocial pathway to alcoholism

The authors examined heterogeneity in risk for externalizing symptoms in children of alcoholic parents, as it may inform the search for entry points into an antisocial pathway to alcoholism. That is, they tested whether the number of alcoholic parents in a family, the comorbid subtype of parental alcoholism, and the gender of the child predicted trajectories of externalizing symptoms over the early life course, as assessed in high-risk samples of children of alcoholic parents and matched controls. Through integrative analyses of 2 independent, longitudinal studies, they showed that children with either an antisocial alcoholic parent or 2 alcoholic parents were at greatest risk for externalizing symptoms. Moreover, children with a depressed alcoholic parent did not differ from those with an antisocial alcoholic parent in reported symptoms. These findings were generally consistent across mother, father, and adolescent reports of symptoms; child gender and child age (ages 2 through 17); and the 2 independent studies examined. Multialcoholic and comorbid-alcoholic families may thus convey a genetic susceptibility to dysregulation along with environments that both exacerbate this susceptibility and provide few supports to offset it.     

Liking persons versus liking groups: a dual-process hypothesis

Most research on liking of persons and groups has been conducted within separate paradigms, but the implicit assumption has been that the same processes govern judgments of liking or disliking regardless of the nature of the target. Departing from this assumption, we suggest a dual-process hypothesis according to which people base their liking of a target person primarily on the desirability of the person's characteristics, whereas they base their liking of a group primarily on the degree of similarity between the group and themselves. To test this hypothesis, participants were presented with either positively or negatively valenced sketches that either described an individual person or a group of people. Path analyses revealed that liking of a person was best predicted by desirability ratings, whereas liking of a group was best predicted by similarity ratings. Implications of these findings for stereotype maintenance are discussed. © 1998 John Wiley & Sons, Ltd.     

Conscious control over the content of unconscious cognition

Visual stimuli (primes) presented too briefly to be consciously identified can nevertheless affect responses to subsequent stimuli - an instance of unconscious cognition. There is a lively debate as to whether such priming effects originate from unconscious semantic processing of the primes or from reactivation of learned motor responses that conscious stimuli afford during preceding practice. In four experiments we demonstrate that unconscious stimuli owe their impact neither to automatic semantic categorization nor to memory traces of preceding stimulus-response episodes, but to their match with pre-specified cognitive action-trigger conditions. The intentional creation of such triggers allows actors to control the way unconscious stimuli bias their behaviour.