The Last Dictator Game? Dominance,Reactivity, and the Methodological Artefact in Experimental Economics

The Dictator Game (DG), one of the best-known designs in experimental social science, has been extensively criticized, and declared by some to be defunct, on the grounds that its results are the product of a research artefact. Critics of the DG argue that the behaviour observed in the game (where agents frequently decide to share their money with strangers) is not the outcome of genuine pro-social preferences but must, instead, be interpreted as a response to the cues given by the experimental design, where these cues signal that the game is about ‘sharing’ (i.e. about altruism or pro-social behaviour). Despite this criticism, the DG continues to be extensively used, and some have defended its validity as an instrument capable of measuring the role of social pressure and social norms against economic motivations. This article examines the assumptions implicit in the claim that the DG results are artefactual and spells out the conditions under which the game can be used to test hypotheses about pro-social behaviour. To conclude we show how the DG debate helps to illuminate the pitfalls embedded in the abandonment of the dominance principle, and argue that this is crucial to the expanding agenda of experimental economics.     

Capsaicin-sensitive afferent vagal fibers are involved in concurrent taste aversion learning

Taste aversion learning (TAL) is a type of learning characterized by rejection of a gustatory/flavor stimulus as a consequence of its pairing with visceral discomfort and malaise. TAL can be established in the laboratory by two different behavioral procedures, concurrent or sequential. Neural mechanisms of these learning modalities remain to be elucidated, but several studies have discussed the implication of various anatomical structures, including the vagus nerve. The aim of this study was to examine the role of capsaicin-sensitive vagal afferent fibers in concurrent (Experiment 1) and sequential (Experiment 2) TAL in Wistar rats. Results showed that perivagal administration of capsaicin (1mg of capsaicin dissolved in 1ml of vehicle (10% Tween 80 in oil)) blocked acquisition of concurrent but not sequential TAL. These data support the hypothesis of two different modalities of TAL mediated by distinct neurobiological systems, with vagal nerve participation only being essential in concurrent TAL.     

The phenomenon of the tip of the tongue in aging

This paper presents new data on the tip of the tongue (TOT) phenomenon and its resolution in aging. 140 volunteers ranging from 19 to 82 years participated in an experiment using definitions about common names, proper names, adjectives and verbs to elicit TOTs. We studied the resolution of the TOTs introducing a free word-recall task and a priming task. Older adults experienced more TOTs than younger adults regardless of the level of vocabulary. Phonological priming, and not free recall of words, improved resolution for the older adults. The results are discussed in relation to the theory of the transmission deficit.     

Pretend play: an application of an intervention program in autism

Methodologically and theoretically based on metarrepresentational deficit hypothesis, we design an intervention to teach the mental state of pretense to an autistic boy. The production and comprehension of symbolic play by means of the use of two specific strategies founded on pictorial analogy of the mental representation and process, was the focus of the learning. The efficiency and efectiveness of the program is reflected in the results that indicated the subject's competence to generate and comprehend the pretense as well as to generalize the acquired knowledge into other areas of mentalistic functioning. We discuss the possibility to develop a metarrepresentational knowledge based on the internalizing of the strategies of conceptual support.