On quasivarieties and varieties as categories

Finitary quasivarieties are characterized categorically by the existence of colimits and of an abstractly finite, regularly projective regular generator G. Analogously, infinitary quasivarieties are characterized: one drops the assumption that G be abstractly finite. For (finitary) varieties the characterization is similar: the regular generator is assumed to be exactly projective, i.e., hom(G, –) is an exact functor. These results sharpen the classical characterization theorems of Lawvere, Isbell and other authors.Supported by the Czech Grant Agency (Project 201/02/0148).Special issue of Studia Logica: Algebraic Theory of Quasivarieties Presented by M. E. Adams, K. V. Adaricheva, W. Dziobiak, and A. V. Kravchenko     

When stereotypes get in the way: stereotypes obstruct stereotype-inconsistent trait inferences

There is a growing body of evidence indicating that people spontaneously make trait inferences while observing the behavior of others. The present article reports a series of 5 experiments that examined the influence of stereotypes on the spontaneous inference of traits. Results consistently showed weaker spontaneous trait inferences for stereotype-inconsistent behavioral information than for stereotype-consistent and stereotype-neutral information. Taken together, the current results suggest that specific spontaneous trait inferences become obstructed by inhibitory processes when behavior is inconsistent with an already activated stereotype. These findings are discussed in relation to stereotype maintenance processes and recent models of attribution in social judgment.     

Geometrics and dynamics of a rod determine how it is used for reaching

Displacing an object with a hand-held rod provided a simple paradigm for studying tool use. The authors asked how reaching was affected by manipulations of rod properties. Adults held a rod (length =.10 to 1.5 m), with its tip in the air; walked toward an object on a table; chose a place to stop; and displaced the object with the rod's tip. In 3 experiments (Ns = 9, 22, and 17 participants), the authors manipulated rod length, mass, and mass distribution to determine whether and how geometric and dynamic properties affected the chosen distance and the posture. Both the chosen stopping distance and the postures were well accommodated to rod characteristics. Postural adaptations took place only in the arm, which was organized as a synergy. Predictably, rod length explained most of the variance, but small and reliable differences in both distance and posture depended on mass and mass distribution. The chosen distance anticipated not only rod length but also the upcoming posture needed to control the rod.     

It takes two to mimic: behavioral consequences of self-construals

The present studies demonstrated the moderation of self-construal orientation on mimicry. Recent research has indicated that an interdependent self-construal is associated with assimilation of the other to the self whereas an independent self-construal is associated with minimizing the influence of others on the self (H. R. Markus & S. Kitayama, 1991; D. Stapel & W. Koomen, 2001). Therefore, the authors hypothesized that an interdependent self-construal would be associated with more mimicry than an independent self-construal. When self-construal orientations were experimentally primed, as in Studies 1 and 2, independent self-construals produced less nonconscious mimicry than interdependent self-construals. When self-construals were examined as cultural differences with either a chronically dominant independent (Americans) or interdependent (Japanese) construal of the self, these results were replicated.     

Dogs (Canis familiaris) learn from their owners via observation in a manipulation task

Eighty-seven pet dogs (Canis familiaris) were involved in an experiment in which they had to solve a task to obtain a ball. After witnessing a full demonstration by their owner (10 times pushing the handle of the box, which released a ball), most dogs preferred to touch the handle sooner and more frequently in comparison with other parts of the box, and they used the handle to get the ball. In contrast, dogs in 3 control groups developed their own respective methods. The lack of emergence of the ball and playing after the demonstration did not affect the learning performance strongly. This suggests that in dogs the outcome of a demonstration plays only a restricted role in the manifestation of social learning.     

Those who laugh are defenseless: how humor breaks resistance to influence

Three experiments illustrate that humor in advertisements prevents the development of negative brand associations due to resistance. Previous research on humor in advertising suggested that humor can counter negative responses during ad processing, but less is known about the effect of humor on the development of negative brand associations in memory. Brand associations are important because there is often a time delay between ad exposure and brand decisions. We separately manipulated two typical aspects of humor processing, that is, distraction and positive affect, and examined their effects on the development of respectively negative and positive brand associations. All experiments were conducted with university students as participants. The results showed that resistance causes negative brand associations (Experiments 1 and 2), and humor prevents the development of these negative brand associations more than nondistracting positive stimuli and neutral stimuli (Experiment 2 and 3). The prevention of negative brand associations was caused by the distractive properties of humor. Irrespective of resistance, the positive affect engendered by humor enhanced positive brand associations. Experiment 3 showed that distraction and positive affect in humor uniquely contribute to brand preference. Together, these results illustrate that the effect of humor on resistance follows a two-step process: humor forestalls the development of negative brand associations because of its distractive properties (cognitive mechanism), and engenders positive brand associations because of its positive emotional outcomes (affective mechanism). These effects of humor on brand associations jointly promote brand preference.     

Heartwarming memories: Nostalgia maintains physiological comfort

Nostalgia, a sentimental longing or wistful affection for the past, is a predominantly positive and social emotion. Recent evidence suggests that nostalgia maintains psychological comfort. Here, we propose, and document in five methodologically diverse studies, a broader homeostatic function for nostalgia that also encompasses the maintenance of physiological comfort. We show that nostalgia--an emotion with a strong connotation of warmth--is triggered by coldness. Participants reported stronger nostalgia on colder (vs. warmer) days and in a cold (vs. neutral or warm) room. Nostalgia, in turn, modulates the interoceptive feeling of temperature. Higher levels of music-evoked nostalgia predicted increased physical warmth, and participants who recalled a nostalgic (vs. ordinary autobiographical) event perceived ambient temperature as higher. Finally, and consistent with the close central nervous system integration of temperature and pain sensations, participants who recalled a nostalgic (vs. ordinary autobiographical) event evinced greater tolerance to noxious cold.     

Biased allocation of faces to social categories

Three studies show that social categorization is biased at the level of category allocation. In all studies, participants categorized faces. In Studies 1 and 2, participants overallocated faces with criminal features--a stereotypical negative trait--to the stigmatized Moroccan category, especially if they were prejudiced. On the contrary, the stereotype-irrelevant negative trait stupid did not lead to overallocation to the Moroccan category. In Study 3, using the stigmatized category homosexual, the previously used negative trait criminal--irrelevant to the homosexual stereotype--did not lead to overallocation, but the stereotype-relevant positive trait femininity did. These results demonstrate that normative fit is higher for faces with stereotype-relevant features regardless of valence. Moreover, individual differences in implicit prejudice predicted the extent to which stereotype-relevant traits elicited overallocation: Whereas more negatively prejudiced people showed greater overallocation of faces associated with negative stereotype-relevant traits, they showed less overallocation of faces associated with positive stereotype-relevant traits. These results support our normative fit hypothesis: In general, normative fit is better for faces with stereotypical features. Moreover, normative fit is enhanced for prejudiced individuals when these features are evaluatively congruent. Social categorization thus may be biased in itself.     

Psychopathic Traits of Dutch Adolescents in Residential Care: Identifying Subgroups

The present study examined whether a sample of 214 (52.8% male, M age = 15.76, SD = 1.29) institutionalized adolescents could be classified into subgroups based on psychopathic traits. Confirmatory Factor Analyses revealed a relationship between the subscales of the Youth Psychopathic traits Inventory (YPI) and the three latent constructs of the original model on which it is based. Latent Class Analyses showed that adolescents showing psychopathic traits could be classified into three subgroups. The first group showed low scores on the grandiose/manipulative dimension, the callous/unemotional dimension, and the impulsive/irresponsible dimension (normal group). The second group scored moderate on the grandiose/manipulative dimension and the callous/unemotional dimension and high on the impulsive/irresponsible dimension (impulsive, non-psychopathic-like group). The third group scored high on all three dimensions (psychopathy-like group). The findings revealed that the impulsive, non-psychopathic like group scored significantly higher on internalizing problem behavior compared to the normal group, while the psychopathy-like and the impulsive, non-psychopathic-like group both scored higher on externalizing problem behavior compared to the normal group. Based on a self-report delinquency measure, it appeared that the psychopathy-like group had the highest delinquency rates, except for vandalism. Both the impulsive and psychopathy-like group had the highest scores on the use of soft drugs.