The conjunction fallacy has been a key topic in debates on the rationality of human reasoning and its limitations. Despite extensive inquiry, however, the attempt of providing a satisfactory account of the phenomenon has proven challenging. Here, we elaborate the suggestion (first discussed by Sides et al., 2001) that in standard conjunction problems the fallacious probability judgments experimentally observed are typically guided by sound assessments of confirmation relations, meant in terms of contemporary Bayesian confirmation theory. Our main formal result is (...) a confirmation-theoretic account of the conjuntion fallacy which is proven robust (i.e., not depending on various alternative ways of measuring degrees of confirmation). The proposed analysis is shown distinct from contentions that the conjunction effect is in fact not a fallacy and is compared with major competing explanations of the phenomenon, including earlier references to a confirmation-theoretic account. (shrink)

Inductive reasoning requires exploiting links between evidence and hypotheses. This can be done focusing either on the posterior probability of the hypothesis when updated on the new evidence or on the impact of the new evidence on the credibility of the hypothesis. But are these two cognitive representations equally reliable? This study investigates this question by comparing probability and impact judgments on the same experimental materials. The results indicate that impact judgments are more consistent in time and more accurate than (...) probability judgments. Impact judgments also predict the direction of errors in probability judgments. These findings suggest that human inductive reasoning relies more on estimating evidential impact than on posterior probability. (shrink)

Crupi et al. (Think Reason 14:182–199, 2008) have recently advocated and partially worked out an account of the conjunction fallacy phenomenon based on the Bayesian notion of confirmation. In response, Schupbach (2009) presented a critical discussion as following from some novel experimental results. After providing a brief restatement and clarification of the meaning and scope of our original proposal, we will outline Schupbach’s results and discuss his interpretation thereof arguing that they do not actually undermine our point of view if (...) properly construed. Finally, we will foster such a claim by means of some novel data. (shrink)

It is easy to construct pairs of sentences X, Y that lead many people to ascribe higher probability to the conjunction X‐and‐Y than to the conjuncts X, Y. Whether an error is thereby committed depends on reasoners' interpretation of the expressions “probability” and “and.” We report two experiments designed to clarify the normative status of typical responses to conjunction problems.

Because the conjunction pandq implies p, the value of a bet on pandq cannot exceed the value of a bet on p at the same stakes. We tested recognition of this principle in a betting paradigm that (a) discouraged misreading p as pandnotq, and (b) encouraged genuinely conjunctive reading of pandq. Frequent violations were nonetheless observed. The findings appear to discredit the idea that most people spontaneously integrate the logic of conjunction into their assessments of chance.

According to Kanazawa (Psychol Rev 111:512–523, 2004), general intelligence, which he considers as a synonym of abstract thinking, evolved specifically to allow our ancestors to deal with evolutionary novel problems while conferring no advantage in solving evolutionary familiar ones. We present a study whereby the results contradict Kanazawa’s hypothesis by demonstrating that performance on an evolutionary novel problem (an abstract reasoning task) predicts performance on an evolutionary familiar problem (a social reasoning task).

Epistemologists and philosophers of science have often attempted to express formally the impact of a piece of evidence on the credibility of a hypothesis. In this paper we will focus on the Bayesian approach to evidential support. We will propose a new formal treatment of the notion of degree of confirmation and we will argue that it overcomes some limitations of the currently available approaches on two grounds: (i) a theoretical analysis of the confirmation relation seen as an extension of (...) logical deduction and (ii) an empirical comparison of competing measures in an experimental inquiry concerning inductive reasoning in a probabilistic setting. (shrink)

The conjunction fallacy has been a key topic in debates on the rationality of human reasoning and its limitations. Despite extensive inquiry, however, the attempt to provide a satisfactory account of the phenomenon has proved challenging. Here we elaborate the suggestion (first discussed by Sides, Osherson, Bonini, & Viale, 2002) that in standard conjunction problems the fallacious probability judgements observed experimentally are typically guided by sound assessments of _confirmation_ relations, meant in terms of contemporary Bayesian confirmation theory. Our main formal (...) result is a confirmation-theoretic account of the conjunction fallacy, which is proven _robust_ (i.e., not depending on various alternative ways of measuring degrees of confirmation). The proposed analysis is shown distinct from contentions that the conjunction effect is in fact not a fallacy, and is compared with major competing explanations of the phenomenon, including earlier references to a confirmation-theoretic account. (shrink)

We discuss the probabilistic analysis of explanatory power and prove a representation theorem for posterior ratio measures recently advocated by Schupbach and Sprenger. We then prove a representation theorem for an alternative class of measures that rely on the notion of relative probability distance. We end up endorsing the latter, as relative distance measures share the properties of posterior ratio measures that are genuinely appealing, while overcoming a feature that we consider undesirable. They also yield a telling result concerning formal (...) accounts of explanatory power versus inductive confirmation, thereby bridging our discussion to a so-called no-miracle argument. (shrink)

Probability ratio and likelihood ratio measures of inductive support and related notions have appeared as theoretical tools for probabilistic approaches in the philosophy of science, the psychology of reasoning, and artificial intelligence. In an effort of conceptual clarification, several authors have pursued axiomatic foundations for these two families of measures. Such results have been criticized, however, as relying on unduly demanding or poorly motivated mathematical assumptions. We provide two novel theorems showing that probability ratio and likelihood ratio measures can be (...) axiomatized in a way that overcomes these difficulties. (shrink)

The so‐called problem of irrelevant conjunction has been seen as a serious challenge for theories of confirmation. It involves the consequences of conjoining irrelevant statements to a hypothesis that is confirmed by some piece of evidence. Following Hawthorne and Fitelson, we reconstruct the problem with reference to Bayesian confirmation theory. Then we extend it to the case of conjoining irrelevant statements to a hypothesis that is dis confirmed by some piece of evidence. As a consequence, we obtain and formally present (...) a novel and more troublesome problem of irrelevant conjunction. We conclude by indicating a possible solution based on a measure‐sensitive approach and by critically discussing a major alternative way to address the problem. *Received December 2008; revised August 2009. †To contact the authors, please write to: Department of Philosophy, University of Turin, via Sant'Ottavio 20, 10124 Turin, Italy; e‐mail: [email protected] ; katya.tentori@unitn.it or k.tentori@ucl.ac.uk. (shrink)

The European market has faced a series of recurrent food scares, e.g. mad cow disease, chicken flu, dioxin poisoning in chickens, salmons and recently also in pigs (Italian newspaper Corriere della Sera , 07/12/2008). These food scares have had, in the short term, major socio-economic consequences, eroding consumer confidence and decreasing the willingness to buy potentially risky food products. The research reported in this paper considered the role of commitment to a food product in the context of food scares, and (...) in particular the effect of commitment on the purchasing intentions of consumers, on their attitude towards the product, and on their trust in the food supply chain. After the initial commitment had been obtained, a threat scenario evoking a risk associated with a specific food was presented, and a wider, related request was then made. Finally, a questionnaire tested the effects of commitment on the participants’ attitude towards the product. The results showed that previous commitment can increase consumers’ behavioural intention to purchase and their attitude towards the food product, even in the presence of a potential hazard. (shrink)

We examined how people think about how things could have turned out differently after they made a decision to cooperate or not in three social interactions: the Prisoner’s dilemma (Experiment 1), the Stag Hunt dilemma (Experiment 2), and the Chicken game (Experiment 3). We found that participants who took part in the game imagined the outcome would have been different if a different decision had been made by the other player, not themselves; they did so whether the outcome was good (...) or bad for them, their own choice had been to cooperate or not, and the other player’s choice had been to cooperate or not. Participants who only read about a fictional protagonist’s game imagined changes outside the protagonist’s control (such as the other player’s decision) after a good outcome but within the protagonist’s control (such as the protagonist’s decision) after a bad outcome. The implications for theories of counterfactual thinking and moral decision-making are discussed. (shrink)

In a series of three behavioral experiments, we found a systematic distortion of probability judgments concerning elementary visual stimuli. Participants were briefly shown a set of figures that had two features (e.g., a geometric shape and a color) with two possible values each (e.g., triangle or circle and black or white). A figure was then drawn, and participants were informed about the value of one of its features (e.g., that the figure was a “circle”) and had to predict the value (...) of the other feature (e.g., whether the figure was “black” or “white”). We repeated this procedure for various sets of figures and, by varying the statistical association between features in the sets, we manipulated the probability of a feature given the evidence of another (e.g., the posterior probability of hypothesis “black” given the evidence “circle”) as well as the support provided by a feature to another (e.g., the impact, or confirmation, of evidence “circle” on the hypothesis “black”). Results indicated that participants’ judgments were deeply affected by impact, although they only should have depended on the probability distributions over the features, and that the dissociation between evidential impact and posterior probability increased the number of errors. The implications of these findings for lower and higher level cognitive models are discussed. (shrink)

Searching for information is critical in many situations. In medicine, for instance, careful choice of a diagnostic test can help narrow down the range of plausible diseases that the patient might have. In a probabilistic framework, test selection is often modeled by assuming that people's goal is to reduce uncertainty about possible states of the world. In cognitive science, psychology, and medical decision making, Shannon entropy is the most prominent and most widely used model to formalize probabilistic uncertainty and the (...) reduction thereof. However, a variety of alternative entropy metrics (Hartley, Quadratic, Tsallis, Rényi, and more) are popular in the social and the natural sciences, computer science, and philosophy of science. Particular entropy measures have been predominant in particular research areas, and it is often an open issue whether these divergences emerge from different theoretical and practical goals or are merely due to historical accident. Cutting across disciplinary boundaries, we show that several entropy and entropy reduction measures arise as special cases in a unified formalism, the Sharma–Mittal framework. Using mathematical results, computer simulations, and analyses of published behavioral data, we discuss four key questions: How do various entropy models relate to each other? What insights can be obtained by considering diverse entropy models within a unified framework? What is the psychological plausibility of different entropy models? What new questions and insights for research on human information acquisition follow? Our work provides several new pathways for theoretical and empirical research, reconciling apparently conflicting approaches and empirical findings within a comprehensive and unified information-theoretic formalism. (shrink)

It is easy to construct pairs of sentences X, Y that lead many people to ascribe higher probability to the conjunction X‐and‐Y than to the conjuncts X, Y. Whether an error is thereby committed depends on reasoners' interpretation of the expressions “probability” and “and.” We report two experiments designed to clarify the normative status of typical responses to conjunction problems.

Derived from a rat model, the theory of Sagvolden et al. offers an all-explanatory model of attention-deficit/hyperactivity disorder (ADHD) anatomy, behaviour, and cognition as being caused predominantly by a hypo-dopaminergic mesolimbic (affecting the mesocortical and nigrostriatal) system, leading to abnormal reward and extinction processes. This model suffers from oversimplification and reductionism, reflecting the limitations of the use of animal models to explain higher mental disorders.

Illocutionary force may be qualified according to Aristotle's classical triadic distinction of logos as a degree of verity, ethos as a degree of credibility or authority and pathos as eloquence or passional intensity. Jakobson 's model of linguistic functions can be understood as operating performatively with greater advantages to pragmatic theory than Searle and Vanderveken's taxonomy of illocutionary acts. Consequently, these three dimensions can also be found in the aesthetic as in other linguistic functions proposed by Jakobson when examined from (...) a pragmatic viewpoint. By detecting the direction of fit and establishing a distinction between conversion and constitution, we may better understand not only the difference between the aesthetic and other functions but a variety of instances besides the artistic in which the aesthetic is displayed. Therefore, pathos can be clearly differentiated from the aesthetic as a dimension that may weigh, together with logos and ethos, upon the aesthetic function of an illocutionary act. (shrink)

The development of reflex theory in its Pavlovian interpretation had significant resonance in a wide range of academic research areas. Its impact on the so-called humanities was, perhaps, no less than the effect it had in medical science. The idea of the conditioned reflex suggesting a physiological explanation of behaviour patterns received a particularly warm welcome in philosophy and psychology as it provided a scientifically-based tool for a conceptual u-turn towards objectivism. This article looks into the ways these ideas contributed (...) to the formation of the Soviet language theory, namely, to the sociological interpretation of language development and speech production presented in the pioneering works of Sergej M. Dobrogaev (1873–1952). (shrink)

This article builds upon existing scholarship concerning the relationship between improvisation and composition. Sections 1 to 3 comprise an exploration into and analysis of both the traditional understanding of improvisation and composition as opposing categories, as well as the more modern, nuanced view of their interpenetrating natures. I conclude that the former view should be replaced by the latter. Sections 4 and 5 present and subsequently negate two potential failings of my argument. First, I confront the problem posed by Goehr’s (...) work-concept, whose essence is opposed to the spirit of improvisation, but argue that recording allows for the solidification of these improvisations into works. Secondly, I undermine the view that composition is creation ex nihilo whilst improvisation is the mere reworking of old material. I uncover the originality of improvisation and formulae of composition to restore their compatibility and reinforce improvisation’s status as a method of broad- and narrow-sense composition. (shrink)

ABSTRACTThis commentary questions the presumption in genetic research that a biological connection exists between populations identified as Jewish. The author emphasises that identifying individuals as Jewish based on biological criteria is a sociological process that can draw attention away from other social mechanisms affecting identity construction. She also encourages critical consideration of the possible racialised thinking behind genetic anthropology studies, and the language used to express genetic findings. In conclusion, she calls for a radical cultural shift in the kind of (...) knowledge valued as significant, relevant, and beneficial to the people on whom genetic ancestry studies are carried out and she asks for attention to the political contexts surrounding all such research. (shrink)

This commentary questions the presumption in genetic research that a biological connection exists between populations identified as Jewish. The author emphasises that identifying individuals as Jewish based on biological criteria is a sociological process that can draw attention away from other social mechanisms affecting identity construction. She also encourages critical consideration of the possible racialised thinking behind genetic anthropology studies, and the language used to express genetic findings. In conclusion, she calls for a radical cultural shift in the kind of (...) knowledge valued as significant, relevant, and beneficial to the people on whom genetic ancestry studies are carried out and she asks for attention to the political contexts surrounding all such research. (shrink)

This book offers a compelling account of the evolution of sensibility, weaving together Darwinian and biosemiotic theory. It works along non-anthropomorphic aesthetics of the appreciation and creation of beauty in nature as an end in itself which has practical benefit.

O presente trabalho avalia em que medida o projeto de lei 8.048/2014, pode ser enquadrado como uma tentativa de experimentalismo democrático no Brasil, a partir do resgate do sentido e da prática da soberania popular na construção da democracia, nos termos de um constitucionalismo popular.

As a category, poiesis can be extended beyond the standard anthropocentric use and applied across three radically different scales: auto-poiesis in everyday self-organization of every living creature, phylo-poiesis in the shaping of a species by sexual selection across various generations and onto-poiesis as an individual's development of formal skills and creative modification of its environment. In this paper, I apply these distinctions and argue, following Darwin and Sebeok, for the possibility of considering poietic and aesthetic manifestations among various animal species (...) in their ability of both appreciating and expressing rhythm, visual decorative patterns, and chromatic qualities. In music we can find song and equivalents to instrumental playing (cicadas and crickets), theater in representing fictitious situations (killdeer's broken wing act and playing), acrobatic skills (various types of woodcocks and paradise birds) and dancing (cranes and eleonora cockatoo). I do not claim there is animal art, since the very concept of the “artistic” is a result of convention. What I do assert, however, is that human aesthetic appreciation did not emerge ex nihilo nor was granted by God to humans only (as Wallace believed) but has evolutionary relevance and is preceded by the zoo-aesthetics in many other species. (shrink)

Based on the understanding of aesthetics as the study of all processes and activities related to aesthesis in his original etymological sense as «sensibility», this paper argues that an evolutionary approach must follow the evolution of aesthesis from its inception. A degree of sensibility may perhaps be traced already at molecules sensing borders in DNA replication. The next stage, which may be defined as “cyto-aesthesis”, refers to evidence of cells’ actions to antigens, virus, enzymes or bacteria and other significant elements (...) in the intercellular fluid by their receptors’ sensibility to ligands. Darwin explored plants’ irritability specifically at their tendrils and petioles and there are studies on their sensibility to surface, nutrients, touch, water, temperature, seasonal cycles, color, gravity, and light. All animal species, including human beings, have evolved a keen sensitivity to predators and mates upon which their survival depends following evolutionary priorities and conditions. There is consequently no particular experience that we may call «aesthetic experience», a redundant term, since the whole spectrum of activities and effects of various species’ sensibility involves experiencing the world, namely, aesthesis. (shrink)