Decision framing in judgment aggregation

Judgment aggregation problems are language dependent in that they may be framed in different yet equivalent ways. We formalize this dependence via the notion of translation invariance, adopted from the philosophy of science, and we argue for the normative desirability of translation invariance. We characterize the class of translation invariant aggregation functions in the canonical judgment aggregation model, which requires collective judgments to be complete. Since there are reasonable translation invariant aggregation functions, our result can be viewed as a possibility theorem. At the same time, we show that translation invariance does have certain normatively undesirable consequences (e.g. failure of anonymity). We present a way of circumventing them by moving to a more general model of judgment aggregation, one that allows for incomplete collective judgments.     

Bending without breaking: examining the role of attitudinal ambivalence in resisting persuasive communication

The present research aims at showing that ambivalence may serve an adaptive function: to preserve attitudes and to resist persuasion. In two experiments, participants were exposed to a counter‐attitudinal message attributed to an ingroup majority. Results of both experiments showed that individuals high in ambivalence changed toward the source more than individuals low in ambivalence at the direct level, while at the indirect level––where the link between attitudes and the source's message is less apparent––individuals low in ambivalence changed toward the source more than individuals high in ambivalence. Experiment 2 also showed that this effect is particularly true for high self‐monitoring participants, thereby supporting a motivational interpretation of the effect. Copyright © 2007 John Wiley & Sons, Ltd.     

Persuasive constraint and expert versus non‐expert influence in intention to quit smoking

In a 2 × 2 design, after listing important personal reasons for smoking, 70 smokers were randomly told either that they had sufficient reasons for smoking (low internal constraint to change) or that they did not have sufficient reasons (high internal constraint to change) and were exposed to an anti‐smoking message from a source with either expert (high external constraint to change) or non‐expert (low external constraint to change) status. The main dependent variable was change in intention to give up smoking. The analyses revealed the predicted interaction between external and internal constraint: High internal constraint increased non‐expert influence but not expert influence. Supplementary analysis showed that, when internal constraint was high, non‐expert influence was related to the perceived quality of the message whereas when internal constraint was low, expert influence was related to the source's perceived motivation to inform, i.e. rather than to convince. These results were predicted on the basis of the link that targets establish in social influence settings between constraints to change that are internal (i.e. related to their personal beliefs, feelings or attitudes) and those that are external (i.e. related to the characteristics of the persuasive communication such as the status of the source). Copyright © 2002 John Wiley & Sons, Ltd.     

Detour behaviour in three species of birds: quails (Coturnix sp.), herring gulls (Larus cachinnans) and canaries (Serinus canaria)

Detour behaviour is the ability of an animal to reach a goal stimulus by moving round any interposed obstacle. It has been widely studied and has been proposed as a test of insight learning in several species of mammals, but few data are available in birds. A comparative study in three species of birds, belonging to different eco-ethological niches, allows a better understanding of the cognitive mechanism of such detour behaviour. Young quails (Coturnix sp.), herring gulls (Larus cachinnans) and canaries (Serinus canaria), 1 month old, 10–25 days old and 4–6 months old, respectively, were tested in a detour situation requiring them to abandon a clear view of a biologically interesting object (their own reflection in a mirror) in order to approach that object. Birds were placed in a closed corridor, at one end of which was a barrier through which the object was visible. Four different types of barrier were used: vertical bar, horizontal bar, grid and transparent. Two symmetrical apertures placed midline in the corridor allowed the birds to adopt routes passing around the barrier. After entering the apertures, birds could turn either right or left to re-establish social contact with the object in the absence of any local sensory cues emanating from it. Quails appeared able to solve the task, though their performance depended on the type of barrier used, which appeared to modulate their relative interest in approaching the object or in exploring the surroundings. Young herring gulls also showed excellent abilities to locate spatially the out-of-view object, except when the transparent barrier was used. Canaries, on the other hand, appeared completely unable to solve the detour task, whatever barrier was in use. It is suggested that these species differences can be accounted for in terms of adaptation to a terrestrial or aerial environment.     

Secundum Quid and the Pragmatics of Arguments. The Challenges of the Dialectical Tradition

Argumentation - The phrase secundum quid et simpliciter is the Latin expression translating and labelling the sophism described by Aristotle as connected with the use of some particular expression...     

The social utility of performance-approach goals in a selective educational environment

According to the recent research, the educational system fulfills both an educational function (i.e., teaching and training students) and a selection function (i.e., determining students’ future position in the social hierarchy), particularly in higher education. It has been argued that in the university system the selection function provides a social utility value to performance-approach goals (i.e., the goal to demonstrate one’s own competences relative to others), which in turn increases the extent to which students endorse these goals. Two experiments investigated the influence of the salience of the selection function on performance-approach goals’ social value and endorsement. The results showed that the salience of the selection function increased both performance-approach goal endorsement (experiment 1 and 2) and performance-approach goals’ social utility (experiment 2). These goals’ social utility contributes to explaining the effect of the salience of the selection function on performance-approach goal endorsement. Limitations of the present experiments and practical implications are discussed.     

Walking reduces the gap between encoding and sensorimotor alignment effects in spatial updating of described environments

Spatial updating allows people to keep track of the self-to-object relations during movement. Previous studies demonstrated that physical movement enhanced spatial updating in remote environments, but failed to find the same effect in described environments. However, these studies mainly considered rotation as a physical movement, without examining other types of movement, such as walking. We investigated how walking affects spatial updating within described environments. Using the judgement of relative directions task, we compared the effects of imagination of rotation, physical rotation, and walking on spatial updating. Spatial updating was evaluated in terms of accuracy and response times in different perspectives, and by calculating two indexes, namely the encoding and sensorimotor alignment effects. As regards response times, we found that in the imagination of rotation and physical rotation conditions the encoding alignment effect was higher than the sensorimotor alignment effect, while in the walking condition this gap disappeared. We interpreted these results in terms of an enhanced link between allocentric and sensorimotor representations, due to the information acquired through walking.     

Words and Drugs: Same Mechanisms of Action?

The therapeutic effects of words, rituals and, more in general, of the whole psychosocial context around the patient, have been investigated over the past few years by using the placebo response as a model. Today we are in a good position to study all these complex psychological factors by using a physiological and neuroscientific approach that uses modern neurobiological tools to probe different brain functions. Since a placebo is represented by the whole ritual of the therapeutic act, the main concept that has emerged today is that words and rituals may modulate the same biochemical pathways that are modulated by drugs. Most of our knowledge about these mechanisms comes from the field of pain, and represents a biomedical, psychological and philosophical enterprise that is changing the way we approach and interpret medicine, psychology and human biology. If on the one hand we know some of the mechanisms of drug action in the central nervous system, on the other we can now understand how the therapist’s words may affect different physiological functions. In fact, the placebo effect and the therapist–patient relationship can be approached by using the same biochemical, cellular and physiological tools of the materia medica. Although the responses to the therapist’s words cannot be reduced merely to the action of a single drug, this represents an epochal transition, in which the distinction between psychotherapy and pharmacotherapy is progressively getting thinner, and which helps us overcome the old dichotomy between psychology and biology.