Thinking about conditionals: A study of individual differences

Abstract

Recent studies have shown the existence of two qualitatively distinct groups of people based on how they judge the probability of a conditional statement. The present study was designed to test whether these differences are rooted in distinctive means of processing conditional statements and whether they are linked to differences in general intelligence. In the study, each of 120 participants completed three separate cognitive tasks involving the processing of abstract conditional statements-the probability-of-conditionals task, the conditional truth table task, and the conditional inference task-in addition to completing a test of general intelligence (AH4). The results showed a number of predicted effects: People responding with conditional (rather than conjunctive) probabilities on the first task were higher in cognitive ability, showed reasoning patterns more consistent with a suppositional treatment of the conditional, and showed a strongly "defective" truth table pattern. The results include several novel findings and post challenges to contemporary psychological theories of conditionals.

Chronometric evidence for the dual-process mental model theory of conditional

“…In our theory, p cases are deemed irrelevant for the truth value of the conditional even when explicitly represented through fleshing out; it is precisely the fleshing out process that makes these cases irrelevant for judging the truth value of the sentence. Our account fits with data indicating that indeterminate responses become more frequent with development (Gauffroy & Barrouillet, 2009) as well as in high-capacity individuals (Evans, Handley, Neilens, & Over, 2007), because higher cognitive capacity makes possible the fleshing out process which leads in turn to indeterminate responses. Finally, possibilities that are not represented in any model, even when the fleshing out is completed, would be considered as incompatible with the conditional and as falsifying it.…”

Probability in reasoning: A developmental test on conditionals

“…They explained this response by supposing an incomplete Ramsey test in shallow processors who would cut short the test and stop at the p & q cases. This explanation was corroborated by the fact that conjunctive responders are lower in general intelligence than conditional responders (Evans, Handley, Neilens, & Over, 2007). Working memory capacities are known to be highly related with Gf (Conway, Kane, & Engle, 2003).…”

The modulation of conditional assertions and its effects on reasoning

“…Other theorists have maintained the notion of validity, but postulated a probabilistic semantics for conditionals: "In everyday contexts it seems to be more plausible to interpret conditionals not by material implications, but by much weaker conditional probabilities" (Pfeifer & Kleiter, 2005). Likewise, many theorists have proposed that the probability of a conditional is the corresponding conditional probability of its consequent given its antecedent (e.g., Evans, Handley, Neilens, & Over, 2007;Evans, Handley, & Over, 2003;Hadjichristidis et al, 2001;Over, Hadjichristidis, Evans, Handley, & Sloman, 2007;Oberauer & Wilhelm, 2003). Oberauer and his colleagues have argued that the model theory needs to be revised in order to explain their participants' judgements of the probabilities of conditionals, which usually corroborated the conditional probability hypothesis (Oberauer, Geiger, Fischer, & Weidenfeld, 2007).…”