In everyday conversation &quot;if&quot; is one of the most frequently used conjunctions. This dissertation investigates what meaning an everyday conditional transmits and what inferences it licenses. It is suggested that the nature of the relation between the two propositions in a conditional might play a major role for both questions. Thus, in the experiments reported here conditional statements that describe a causal relationship (e.g., &quot;If you touch that wire, you will receive an electric shock&quot;) were compared to arbitrary conditional statements in which there is no meaningful relation between the antecedent and the consequent proposition (e.g., &quot;If Napoleon is dead, then Bristol is in England&quot;).<br> Initially, central assumptions from several approaches to the meaning and the reasoning from causal conditionals will be integrated into a common model. In the model the availability of exceptional situations that have the power to generate exceptions to the rule described in the conditional (e.g., the electricity is turned off), reduces the subjective conditional probability of the consequent, given the antecedent (e.g., the probability of receiving an electric shock when touching the wire). This conditional probability determines people's degree of belief in the conditional, which in turn affects their willingness to accept valid inferences (e.g., &quot;Peter touches the wire, therefore he receives an electric shock&quot;) in a reasoning task. Additionally to this indirect pathway, the model contains a direct pathway: Cognitive availability of exceptional situations directly reduces the readiness to accept valid conclusions.<br> The first experimental series tested the integrated model for conditional statements embedded in pseudo-natural cover stories that either established a causal relation between the antecedent and the consequent event (causal conditionals) or did not connect the propositions in a meaningful way (arbitrary conditionals). The model was supported for the causal, but not for the arbitrary conditional statements. Furthermore, participants assigned lower degrees of belief to arbitrary than to causal conditionals. Is this effect due to the presence versus absence of a semantic link between antecedent and consequent in the conditionals?<br> This question was one of the starting points for the second experimental series. Here, the credibility of the conditionals was manipulated by adding explicit frequency information about possible combinations of presence or absence of antecedent and consequent events to the problems (i.e., frequencies of cases of 1. true antecedent with true consequent, 2. true antecedent with false consequent, 3. false antecedent with true consequent, 4. false antecedent with false consequent). This paradigm allows testing different approaches to the meaning of conditionals (Experiment 4) as well as theories of conditional reasoning against each other (Experiment 5).<br> The results of Experiment 4 supported mainly the conditional probability approach to the meaning of conditionals (Edgington, 1995) according to which the degree of belief a listener has in a conditional statement equals the conditional probability that the consequent is true given the antecedent (e.g., the probability of receiving an electric shock when touching the wire). Participants again assigned lower degrees of belief to the arbitrary than the causal conditionals, although the conditional probability of the consequent given the antecedent was held constant within every condition of explicit frequency information. This supports the hypothesis that the mere presence of a causal link enhances the believability of a conditional statement. In Experiment 5 participants solved conditional reasoning tasks from problems that contained explicit frequency information about possible relevant cases. The data favored the probabilistic approach to conditional reasoning advanced by Oaksford, Chater, and Larkin (2000).<br> The two experimental series reported in this dissertation provide strong support for recent probabilistic theories: for the conditional probability approach to the meaning of conditionals by Edgington (1995) and the probabilistic approach to conditional reasoning by Oaksford et al. (2000). In the domain of conditional reasoning, there was additionally support for the modified mental model approaches by Markovits and Barrouillet (2002) and Schroyens and Schaeken (2003). Probabilistic and mental model approaches could be reconciled within a dual-process-model as suggested by Verschueren, Schaeken, and d&#39;Ydewalle (2003). / Im Laufe eines Tages verwenden die meisten Menschen mehrfach Konditionalsätze: Das Wörtchen &quot;wenn&quot; gehört zu den häufigsten Konjunktionen in Alltag, Wissenschaft und Literatur. Die vorliegende Dissertation beschäftigt sich mit der Frage, welche Bedeutung ein Konditionalsatz im alltäglichen Sprachgebrauch übermittelt und welche Inferenzen er erlaubt. Es wird die Vermutung aufgestellt, dass dabei die Art der Relation zwischen den zwei Propositionen in einem Konditional eine bedeutsame Rolle spielen könnte. Daher werden in den Experimenten Konditionalsätze, die eine kausale Beziehung beschreiben (z.B. &quot;Wenn Du das Kabel berührst, bekommst Du einen elektrischen Schlag&quot;) mit arbiträren Konditionalen verglichen, in denen keinerlei sinnvolle Relation zwischen Antezedens und Konsequens besteht (z.B. &quot;Wenn Napoleon tot ist, liegt Bristol in England&quot;).<br> Als erstes werden zentrale Annahmen von mehreren Ansätzen zur Bedeutung und zum Schlußfolgern mit kausalen Konditionalsätzen in ein gemeinsames Modell integriert. In dem Modell reduziert die kognitive Verfügbarkeit von Situationen, die zu Ausnahmen von der Regel im Konditionalsatz führen können (z.B. der Strom ist abgestellt), die subjektive bedingte Wahrscheinlichkeit des Konsequens gegeben das Antezedens (z.B. die Wahrscheinlichkeit, einen Schlag zu bekommen gegeben, dass man das Kabel berührt). Diese subjektive bedingte Wahrscheinlichkeit bestimmt die Glaubwürdigkeit des Konditionals, die wiederum die Bereitwilligkeit beeinflußt, mit der gültige Schlußfolgerungen (z.B. &quot;Peter berührt das Kabel, daher erhält er einen elektrischen Schlag&quot;) in einer Schlußfolgerungsaufgabe akzeptiert werden. Zusätzlich zu dem gerade beschriebenen indirekten Pfad enthält das integrierte Modell zusätzlich einen direkten Pfad: Die kognitive Verfügbarkeit von Ausnahme-Situationen reduziert unmittelbar die Bereitschaft, gültige Schlüsse zu akzeptieren. Die erste Experimentalreihe testete das entwickelte integrierte Model für Konditionalsätze, die in pseudo-natürliche Kontextgeschichten eingebettet wurden. Die Kontextgeschichten stellten entweder eine kausale Relation zwischen Antezedens und Konsequens her (kausale Konditionale) oder stellten die Propositionen in keinerlei sinnvollen Zusammenhang (arbiträre Konditionale). Die empirischen Daten stützen das Modell für die kausalen, aber nicht für die arbiträren Konditionale. Außerdem schätzten die TeilnehmerInnen die arbiträren Konditionalsätzen als weniger glaubwürdig ein als die kausalen Konditionale. Es stellt sich die Frage, ob dieser Unterschied in der Glaubwürdigkeit auf die An- bzw. Abwesenheit einer bedeutungshaltigen Relation zwischen Antezedens und Konsequens im Konditional zurückgeführt werden kann.<br> Diese Frage war einer der Ausgangspunkte für die zweite Experimentalreihe. In dieser wurde die Glaubwürdigkeit der Konditionalsätze kontrolliert manipuliert, indem in den Kontextgeschichten explizite Häufigkeitsinformationen über die vier möglichen Kombinationen von An- bzw. Abwesenheit von Antezedens und Konsequens gegeben wurden (d.h. die Häufigkeit von Fällen mit 1. wahrem Antezedens und wahrem Konsequens, 2. wahrem Antezedens und falschem Konsequens, 3. falschem Antezedens und wahrem Konsequens, 4. falschem Antezedens und falschem Konsequens). Dieses Paradigma ermöglichte ferner, unterschiedliche Ansätze zur Bedeutung des Konditionals (Experiment 4) ebenso wie Theorien zum konditionalen Schlußfolgern gegeneinander zu testen (Experiment 5). Die Befunde aus Experiment 4 stützen im wesentlichen Edgingtons Ansatz zur Bedeutung von Konditionalen (Edgington, 1995). Nach diesem Ansatz entspricht die Glaubwürdigkeit, die ein Zuhörer einem Konditionalsatz einräumt, der bedingten Wahrscheinlichkeit, dass das Konsequens wahr ist gegeben das Antezedens (z.B. die Wahrscheinlichkeit, einen Schlag zu bekommen gegeben, dass man das Kabel berührt). Erneut schrieben die TeilnehmerInnen den arbiträren Konditionalsätzen geringere Glaubwürdigkeit zu als den kausalen Sätzen, obwohl diesmal innerhalb jeder Häufigkeitsbedingung die bedingte Wahrscheinlichkeit des Konsequens gegeben das Antezedens konstant gehalten wurde. Dieses Ergebnis stützt die Hypothese, dass die bloße Anwesenheit einer kausalen Beziehung die Glaubwürdigkeit eines Konditionalsatzes erhöht. In Experiment 5 lösten die TeilnehmerInnen konditionale Schlußfolgerungsaufgaben, dabei wurden die Kontextgeschichten um explizite Häufigkeitsangaben ergänzt. Die Ergebnisse favorisieren die probabilistische Theorie zum konditionalen Schließen, die von Oaksford, Chater, und Larkin (2000) vorgeschlagen wurde. Beide Experimentalreihen lieferten deutliche Evidenz für probabilistische Theorien: für Edgingtons Ansatz zur Bedeutung von Konditionalsätzen (Edgington, 1995) und für die probabilistische Theorie des konditionalen Schließens von Oaksford et al. (2000). Im Bereich des konditionalen Schließens stützen die Daten gleichzeitig die modifizierten mentalen Modell-Theorien von Markovits und Barrouillet (2002) und Schroyens und Schaeken (2003). Probabilistische und mentale Modell-Theorien könnten im Rahmen eines Dualen-Prozeß-Modells wie es von Verschueren, Schaeken und d&#39;Ydewalle (2003) vorgeschlagen wurde, miteinander versöhnt werden.

Numerous recent publications on the psychological meaning of “if” have proposed a probabilistic interpretation of conditional sentences. According to the proponents of probabilistic approaches, sentences like “If the weather is nice, I will be at the beach tomorrow” (or “If p, then q” in the abstract version) express a high probability of the consequent (being at the beach), given the antecedent (nice weather). When people evaluate conditional sentences, they assumingly do so by deriving the conditional probability P(q|p) using a procedure called the Ramsey test. This is a contradicting view to the hitherto dominant Mental Model Theory (MMT, Johnson-Laird, 1983), that proposes conditional sentences refer to possibilities in the world that are represented in form of mental models. Whereas probabilistic approaches gained a lot of momentum in explaining the interpretation of conditionals, there is still no conclusive probabilistic account of conditional reasoning. This thesis investigates the potential of a comprehensive probabilistic account on conditionals that covers the interpretation of conditionals as well as conclusion drawn from these conditionals when used as a premise in an inference task. The first empirical chapter of this thesis, Chapter 2, implements a further investigation of the interpretation of conditionals. A plain version of the Ramsey test as proposed by Evans and Over (2004) was tested against a similarity sensitive version of the Ramsey test (Oberauer, 2006) in two experiments using variants of the probabilistic truth table task (Experiments 2.1 and 2.2). When it comes to decide whether an instance is relevant for the evaluation of a conditional, similarity seems to play a minor role. Once the decision about relevance is made, believability judgments of the conditional seem to be unaffected by the similarity manipulation and judgments are based on frequency of instances, in the way predicted by the plain Ramsey test. In Chapter 3 contradicting predictions of the probabilistic approaches on conditional reasoning of Verschueren et al (2005), Evans and Over (2004) and Oaksford & Chater (2001) are tested against each other. Results from the probabilistic truth table task modified for inference tasks supports the account of Oaksford and Chater (Experiment 3.1). A learning version of the task and a design with every day conditionals yielded results unpredicted by any of the theories (Experiments 3.2-3.4). Based on these results, a new probabilistic 2-stage model of conditional reasoning is proposed. To preclude claims that the use of the probabilistic truth table task (or variants thereof) favors judgments reflecting conditional probabilities, Chapter 4 combines methodologies used by proponents of the MMT with the probabilistic truth table task. In three Experiments (4.1 -4.3) it could be shown for believability judgments of the conditional and inferences drawn from it, that causal information about counterexamples only prevails, when no frequencies of exceptional cases are present. Experiment 4.4 extends these findings to every day conditionals. A probabilistic estimation process based on frequency information is used to explain results on all tasks. The findings confirm with a probabilistic approach on conditionals and moreover constitute an explanatory challenge for the MMT. In conclusion of all the evidence gathered in this dissertation it seems justified to draw the picture of a comprehensive probabilistic view on conditionals quite optimistically. Probability estimates not only explain the believability people assign to a conditional sentence, they also explain to what extend people are willing to draw conclusions from those sentences. / Zahlreiche aktuelle Publikationen über die psychologische Bedeutung der Worte „Wenn - dann“ schlagen eine probabilistische Interpretation von Konditionalen vor. Vertretern dieses probabilistischen Ansatz zufolge drücken Sätze der Form „Wenn das Wetter schön ist, dann bin ich morgen am Strand“ (oder „Wenn p, dann q“ in der abstrakten Version) eine hohe Wahrscheinlichkeit des Konsequenten (am Strand sein), gegeben den Antezedenten (schönes Wetter) aus. Menschen beurteilen demnach Konditionalsätze, indem sie die bedingte Wahrscheinlichkeit P(q|p) mit Hilfe eines Ramsey-Tests abschätzen (Evans & Over, 2004). Diese Sichtweise stellt einen Gegenentwurf zur bisher dominanten Theorie mentaler Modelle (Johnson-Laird, 1983) dar, die davon ausgeht, dass Konditionalsätze Aussagen über Möglichkeiten machen, die in Form mentaler Modelle repräsentiert werden. Obwohl probabilistische Ansätze in den letzten Jahren überzeugende Evidenz für eine probabilistische Interpretation von Konditionalen präsentiert haben, gibt es noch keine überzeugende probabilistische Erklärung für konditionales Schließen. Die vorliegende Doktorarbeit leistet einen Beitrag zu einer umfassenden probabilistischen Theorie von Konditionalen, die die Interpretation und die Ziehung von Schlüssen aus Konditionalsätzen umfasst.

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A presente tese apresenta uma investigação acerca do desenvolvimento do raciocínio condicional, considerado um componente chave do pensamento lógico-dedutivo, em crianças e adolescentes que participaram de uma experiência de programação com o software Squeak Etoys. O desenvolvimento do raciocínio condicional é classificado em etapas relacionadas à composição e reversão de transformações que operam sobre a implicação, culminando com a plena reversibilidade que corresponde, na teoria piagetiana, à construção e mobilização do grupo de transformações INRC (Identidade, Negação, Recíproca, Correlativa). Tais etapas são identificadas a partir de entrevistas realizadas segundo o método clínico piagetiano, através da aplicação de três desafios de programação com complexidade crescente, cuja solução envolvia o uso da operação lógica da implicação. As entrevistas foram realizadas com oito crianças, com idades entre 10 e 16 anos, que cursavam as séries finais do Ensino Fundamental de duas escolas públicas. Com base nos dados, a análise revela a importância do pensamento combinatório, que permite aos adolescentes testarem, sistematicamente, todas as possibilidades de ordenamento e inclusão dos comandos sugeridos, e a obterem as conclusões lógicas adequadas, enquanto que as crianças mais novas não obtém o mesmo êxito. Além disso, na tese é realizada uma discussão sobre a inclusão da escola numa cultura digital sob uma perspectiva construtivista de construção do conhecimento. Nesse contexto, a metodologia de projetos de aprendizagem foi apresentada como sendo adequada e o software Squeak Etoys despontou como uma possibilidade interessante de se desenvolver projetos e de promover a aprendizagem de matemática. Por último, neste trabalho também é realizado um debate sobre a importância de se aprender a programar na escola. / The present thesis presents an investigation into the development of conditional reasoning, considered a key component of logical-deductive thinking, in children and adolescents who participated in a programming experience with the software Squeak Etoys. The development of conditional reasoning is classified into stages related to the composition and reversal of transformations that operate on the implication, culminating in the full reversibility that corresponds, in Piaget’s theory, to the construction and mobilization of the Transformations INRC (Identity, Negation, Reciprocity and Correlation). These steps are identified from interviews conducted according to Piaget’s clinical method, through the application of three programming challenges with increasing complexity, whose solution involved the use of the logical operation of the implication. The interviews were conducted with eight children aged 10-16, who attended the final series of the Elementary School of two public schools. Based on the data, the analysis revealed the importance of combining thinking, which allows teenagers to systematically test all the possibilities for ordering and inclusion of the suggested commands, and to obtain the appropriate logical conclusions, while younger children do not achieve the same results. Moreover, in the thesis a discussion is conducted on the inclusion of the school in a digital culture under a constructivist perspective of building knowledge. In this context, the methodology of learning through projects has been presented as being appropriate and the Squeak Etoys software has appeared as an interesting possibility of developing projects and promoting the learning of mathematics. Finally, in this study a debate is also conducted on the importance of learning to plan in the school.

This study applied the Process Dissociation Procedure (Bornstein, 2002) to test independence between personality processes represented by different implicit measurement techniques. In contrast to the commonly adopted literal view of dual processes in personality theory, the study predicted that two implicit measures (CRT-A and IAT-A) and one explicit measure (NEO-AH) of aggressive disposition would dissociate with each other in their 1) intercorrelations, 2) predictions of behavioral criteria of aggressiveness, and 3) potential moderation by situational cues. These hypotheses were generally, though not completely, supported. Most importantly, the two implicit measures dissociated in their lack of correlation and differential prediction of behavioral criteria, unaffected by changes in situational cues. As predicted, the CRT-A and the NEO-AH dissociated in their intercorrelations, predictions, and moderation by incentives. The IAT-A and the NEO-AH dissociated in their lack of intercorrelation and their differential moderation by changes in incentive conditions. As predicted, only the explicit measure was moderated by changes in incentive conditions. Unexpectedly, IAT-A and the NEO-AH were statistically indistinguishable in their prediction of behavioral criteria of aggression. The findings provided strong support for the hypotheses predicting multiple independent implicit personality processes.

A presente tese apresenta uma investigação acerca do desenvolvimento do raciocínio condicional, considerado um componente chave do pensamento lógico-dedutivo, em crianças e adolescentes que participaram de uma experiência de programação com o software Squeak Etoys. O desenvolvimento do raciocínio condicional é classificado em etapas relacionadas à composição e reversão de transformações que operam sobre a implicação, culminando com a plena reversibilidade que corresponde, na teoria piagetiana, à construção e mobilização do grupo de transformações INRC (Identidade, Negação, Recíproca, Correlativa). Tais etapas são identificadas a partir de entrevistas realizadas segundo o método clínico piagetiano, através da aplicação de três desafios de programação com complexidade crescente, cuja solução envolvia o uso da operação lógica da implicação. As entrevistas foram realizadas com oito crianças, com idades entre 10 e 16 anos, que cursavam as séries finais do Ensino Fundamental de duas escolas públicas. Com base nos dados, a análise revela a importância do pensamento combinatório, que permite aos adolescentes testarem, sistematicamente, todas as possibilidades de ordenamento e inclusão dos comandos sugeridos, e a obterem as conclusões lógicas adequadas, enquanto que as crianças mais novas não obtém o mesmo êxito. Além disso, na tese é realizada uma discussão sobre a inclusão da escola numa cultura digital sob uma perspectiva construtivista de construção do conhecimento. Nesse contexto, a metodologia de projetos de aprendizagem foi apresentada como sendo adequada e o software Squeak Etoys despontou como uma possibilidade interessante de se desenvolver projetos e de promover a aprendizagem de matemática. Por último, neste trabalho também é realizado um debate sobre a importância de se aprender a programar na escola. / The present thesis presents an investigation into the development of conditional reasoning, considered a key component of logical-deductive thinking, in children and adolescents who participated in a programming experience with the software Squeak Etoys. The development of conditional reasoning is classified into stages related to the composition and reversal of transformations that operate on the implication, culminating in the full reversibility that corresponds, in Piaget’s theory, to the construction and mobilization of the Transformations INRC (Identity, Negation, Reciprocity and Correlation). These steps are identified from interviews conducted according to Piaget’s clinical method, through the application of three programming challenges with increasing complexity, whose solution involved the use of the logical operation of the implication. The interviews were conducted with eight children aged 10-16, who attended the final series of the Elementary School of two public schools. Based on the data, the analysis revealed the importance of combining thinking, which allows teenagers to systematically test all the possibilities for ordering and inclusion of the suggested commands, and to obtain the appropriate logical conclusions, while younger children do not achieve the same results. Moreover, in the thesis a discussion is conducted on the inclusion of the school in a digital culture under a constructivist perspective of building knowledge. In this context, the methodology of learning through projects has been presented as being appropriate and the Squeak Etoys software has appeared as an interesting possibility of developing projects and promoting the learning of mathematics. Finally, in this study a debate is also conducted on the importance of learning to plan in the school.

A presente tese apresenta uma investigação acerca do desenvolvimento do raciocínio condicional, considerado um componente chave do pensamento lógico-dedutivo, em crianças e adolescentes que participaram de uma experiência de programação com o software Squeak Etoys. O desenvolvimento do raciocínio condicional é classificado em etapas relacionadas à composição e reversão de transformações que operam sobre a implicação, culminando com a plena reversibilidade que corresponde, na teoria piagetiana, à construção e mobilização do grupo de transformações INRC (Identidade, Negação, Recíproca, Correlativa). Tais etapas são identificadas a partir de entrevistas realizadas segundo o método clínico piagetiano, através da aplicação de três desafios de programação com complexidade crescente, cuja solução envolvia o uso da operação lógica da implicação. As entrevistas foram realizadas com oito crianças, com idades entre 10 e 16 anos, que cursavam as séries finais do Ensino Fundamental de duas escolas públicas. Com base nos dados, a análise revela a importância do pensamento combinatório, que permite aos adolescentes testarem, sistematicamente, todas as possibilidades de ordenamento e inclusão dos comandos sugeridos, e a obterem as conclusões lógicas adequadas, enquanto que as crianças mais novas não obtém o mesmo êxito. Além disso, na tese é realizada uma discussão sobre a inclusão da escola numa cultura digital sob uma perspectiva construtivista de construção do conhecimento. Nesse contexto, a metodologia de projetos de aprendizagem foi apresentada como sendo adequada e o software Squeak Etoys despontou como uma possibilidade interessante de se desenvolver projetos e de promover a aprendizagem de matemática. Por último, neste trabalho também é realizado um debate sobre a importância de se aprender a programar na escola. / The present thesis presents an investigation into the development of conditional reasoning, considered a key component of logical-deductive thinking, in children and adolescents who participated in a programming experience with the software Squeak Etoys. The development of conditional reasoning is classified into stages related to the composition and reversal of transformations that operate on the implication, culminating in the full reversibility that corresponds, in Piaget’s theory, to the construction and mobilization of the Transformations INRC (Identity, Negation, Reciprocity and Correlation). These steps are identified from interviews conducted according to Piaget’s clinical method, through the application of three programming challenges with increasing complexity, whose solution involved the use of the logical operation of the implication. The interviews were conducted with eight children aged 10-16, who attended the final series of the Elementary School of two public schools. Based on the data, the analysis revealed the importance of combining thinking, which allows teenagers to systematically test all the possibilities for ordering and inclusion of the suggested commands, and to obtain the appropriate logical conclusions, while younger children do not achieve the same results. Moreover, in the thesis a discussion is conducted on the inclusion of the school in a digital culture under a constructivist perspective of building knowledge. In this context, the methodology of learning through projects has been presented as being appropriate and the Squeak Etoys software has appeared as an interesting possibility of developing projects and promoting the learning of mathematics. Finally, in this study a debate is also conducted on the importance of learning to plan in the school.

Leadership in stressful and dangerous situations is vitally important in terms of lives, property, and national strategic objectives. But our understanding of effective leadership in these and other contexts is limited. Part of the problem is that interactionist theoretical perspectives are not reflected in contemporary leadership thinking. In addition, the impact of individual differences on leadership is often misrepresented or hidden by linear correlations and regressions conducted on continuous scores. This study employed new, innovative, indirect conditional reasoning measures to assess the personalities of 627 leaders entering the militaryâ s most challenging and stressful combat leader development course (the US Army Ranger School). These innovative measures predicted compelling differences in leadership, attrition, and in the peer evaluations made during the training. Analyses conducted on the continuous personality scores demonstrate that these findings are misrepresented or hidden by linear correlations and regressions. As an alternative, I present a configural scoring scheme, couched in a poker analogy, to explain how these individual differences combine to predict the odds of success for each of the 18 personality types studied.