Contraexemplos e raciocínio dedutivo

Tese de Doutoramento apresentada ao ISPA - Instituto UniversitárioEste trabalho foi desenvolvido com o objectivo de contribuir para uma compreensão mais alargada do modo como os sujeitos utilizam os contraexemplos no raciocínio condicional, quando são utilizados conteúdos que remetem para situações comuns do quotidiano. Não existem dúvidas de que as pessoas são capazes de recuperar contraexemplos, vários estudos atestam esta capacidade (e.g. Couto, Quelhas & Juhos, 2010; De Neys & Everaerts, 2008; De Neys, Schaeken & D’ydewalle, 2002; Neys, Schaeken & d'Ydewalle, 2003b;Verschueren, Schaeken, De Neys & d'Ydewalle, 2004). No entanto, a forma como os sujeitos recuperam e utilizam contraexemplos, carece ainda de esclarecimentos. Para cumprir este objectivo geral, construímos dois conjuntos de experiências que incidem em dois factores importantes. Em primeiro lugar investigámos a recuperação de contraexemplos e aceitação de inferências, com avisos e conselhos. Na experiência 1, verificámos que os sujeitos são capazes de gerar contraexemplos para ambos os tipos de frase, mas não o fazem com igual frequência para avisos e conselhos. Em seguida, nas Experiências 2 e 3 investigámos o impacto da disponibilidade (Experiência 2) e da recuperação (Experiência 3) de contraexemplos, nas inferências que os sujeitos fazem, tendo concluído com alguma surpresa que este impacto é muito pequeno ao contrário do que se sabe acontecer com condicionais causais (e.g. Byrne, Espino & Santamaria, 1999; Couto, Quelhas & Juhos, 2010; Cummins, 1995; Cummins, Lubart, Alksnis & Rist, 1991). Ainda no primeiro no conjunto de experiências, avaliámos os padrões de interpretação que os sujeitos fazem com base nestas condicionais (Experiência 4), tendo concluído que existe uma variabilidade grande das interpretações que os sujeitos fazem. No segundo conjunto de experiências, recorremos a frases causais para estudar o impacto da recuperação de contraexemplos adicionais. A Experiência 5 demonstra que a recuperação de contraexemplos é um processo pouco fluente e que esta sensação de falta de fluência afecta o valor que os sujeitos atribuem aos contraexemplos, conduzindo a um padrão de supressão de inferências contrário à informação que foi recuperada. A Experiência 6 esclarece que o padrão de supressão reportado na Experiência 5 se deve às dificuldades de recuperação dos contraexemplos. Quando estes são fornecidos aos sujeitos, em vez de recuperados da memória, o padrão de supressão corresponde ao conteúdo que foi apresentado, ou seja, mais contraexemplos conduzem a maior supressão. Na Experiência 7 confrontámos contraexemplos e a frequência de Excepções, tendo concluído que os sujeitos parecem preferir a informação probabilística, à informação que decorre dos contraexemplos. No geral, os nossos resultados mostram três factos importantes. Em primeiro lugar que o conhecimento que é recuperado durante o raciocínio tem diferentes funções para diferentes tipos de condicionais, isto é, os contraexemplos recuperados para Advice têm uma função diferente dos contraexemplos recuperados para condicionais causais. Além disto, mostra ainda que o processo de recuperação de contraexemplos é pouco fluente e as pessoas parecem preferir utilizar a informação probabilística. Por fim, esclarece que os dois factores acima mencionados ajudam a explicar as diferenças que têm sido encontradas na literatura sobre o peso que cada contraexemplo adicional tem na aceitação de inferências.We have developed this thesis with the goal of contributing to a larger understanding of the way in which people use counterexamples during conditional reasoning, when they reason about contents that refer to situations that are common on their daily lives. There is no doubt that people are able to retrieve counterexamples, and many studies attest this ability (e.g. Couto, Quelhas & Juhos, 2010; De Neys & Everaerts, 2008; De Neys, Schaeken & D’ydewalle, 2002; Neys, Schaeken & d'Ydewalle, 2003b;Verschueren, Schaeken, De Neys & d'Ydewalle, 2004). However, the way in which people retrieve and use counterexamples is still in need of some enlightenment. In order to attain our goal, we have developed two sets of experiments, which focus on two important factors. We started by investigating the counterexample retrieval and endorsement of inferences for advice conditionals. On the first experiment, we verified that subjects are capable of generating counterexamples to advice conditionals, but they do it differently for tips and warnings. Following this, on Experiments 2 and 3 we evaluated the impact of the availability (Experiment 2) and the retrieval (Experiment 3) of counterexamples, on the inferences that people draw from advice. Surprisingly, we have concluded that this impact is very little, contrary to what has been found for causal conditionals (e.g. Byrne, Espino & Santamaria, 1999; Couto, Quelhas & Juhos, 2010; Cummins, 1995; Cummins, Lubart, Alksnis & Rist, 1991). Finally, on this first set of experiments, we also investigated the interpretations that people make, based on tips and warnings (Experiment 4), and we concluded that there is an enormous variability of interpretations from advice conditionals. On the second set of experiments, we resorted to causal conditionals to study the impact that retrieving additional counterexamples has on conditional inferences. Experiment 5 shows that retrieving counterexamples is not a fluent process, and that this lack of fluency has a deep impact on the value that people attribute to the retrieved counterexamples, thus leading to a pattern of suppression that is contrary to the information that was recovered. Experiment 6 clarifies that the pattern of suppression reported on Experiment 5 is due to difficulties in the retrieval process. When counterexamples are presented instead of retrieved from memory, the suppression of inferences is compatible with the information that was presented to the participants, that is, more contrerexamples equal more suppression of inferences. On Experiment 7, we confronted counterexamples and the frequency of exceptions, and we concluded that subjects show a preference for probabilistic information, rather than counterexample information, when they make conditional inferences. Overall, our results show three important factors. First, the knowledge retrieved during reasoning has different purposes for different sorts of conditionals, i.e., counterexamples recovered for Advice have a different purpose than counterexamples recovered for causal conditionals. Our results also show that counterexample retrieval is not a fluent process and that people prefer to use probabilistic information. The results above mentioned, aid in explaining the differences that have been found about the weight that additional counterexamples have on inference acceptance rates.Fundação para a Ciência e a Tecnologia (FCT

Counterfactual thinking: Study of the focus effect of scenarios and blame ascriptions to victim and perpetrator

In two different studies we examined the focus effect of a scenario (i.e., the fact that a given character is the protagonist of a story) on two interconnected domains: the generation of counterfactual thoughts and the ascription of blame. It was hypothesised that being the focal agent of a story would not only lead to more counterfactuals centred on him or her, but also to greater ascriptions of blame as it would be easier to imagine how that actor could have behaved differently had he chosen or wanted to, and thus avoided a deleterious outcome. Different negatively-valenced scenarios depicting a certain misfortune such as a mugging were created in which victim, perpetrator or both characters were the centre of the story. Results showed that placing either victim or perpetrator as the protagonist of a scenario increases the number of counterfactual thoughts centred on that character, but does not necessarily increase the blame attributed to him or her as the perpetrator was always ascribed more blame than the victim, irrespective of who was the protagonist. Study 2’s findings replicate those of Study 1 even with a different experimental design, modified materials, and various counterbalancing measures, hence suggesting that being the protagonist enables one to easily consider counterfactual alternatives involving that actor, but does not prevent one from identifying who is rightfully to blame for a given misfortune. The results and their implications were interpreted according to different theoretical perspectives and possible future avenues of research are discussed

Advice conditionals about tips and warnings: Interpretations and inferences

Two experiments examine how people interpret and reason about advice conditionals, such as tips, for example, “if you study more your grades will improve”, and warnings, for example, “if you stop exercising you will gain weight”. Experiment 1 showed that when participants reason about whether a tip or warning could be true in different situations, their judgments correspond to a biconditional or conditional interpretation on about half of all trials, but to an enabling or tautology interpretation on many others. Experiment 2 showed that participants make few modus ponens and tollens inferences from tips and warnings, and more modus ponens inferences from tips than warnings. The implications for alternative theories are discussed.Fundação para a Ciência e a Tecnologia (FCT)info:eu-repo/semantics/publishedVersio