Fluency and belief bias in deductive reasoning: new indices for old effects

Abstract

Models based on signal detection theory (SDT) have occupied a prominent role in domains such as perception, categorization, and memory. Recent work by Dube et al. (2010) suggests that the framework may also offer important insights in the domain of deductive reasoning. Belief bias in reasoning has traditionally been examined using indices based on raw endorsement rates—indices that critics have claimed are highly problematic. We discuss a new set of SDT indices fit for the investigation belief bias and apply them to new data examining the effect of perceptual disfluency on belief bias in syllogisms. In contrast to the traditional approach, the SDT indices do not violate important statistical assumptions, resulting in a decreased Type 1 error rate. Based on analyses using these novel indices we demonstrate that perceptual disfluency leads to decreased reasoning accuracy, contrary to predictions. Disfluency also appears to eliminate the typical link found between cognitive ability and the effect of beliefs on accuracy. Finally, replicating previous work, we demonstrate that cognitive ability leads to an increase in reasoning accuracy and a decrease in the response bias component of belief bias.

When fast logic meets slow belief: Evidence for a parallel-processing model of belief bias

“… 2 The confidence ratings were collected with the aim to conduct signal detection theory (SDT) analyses (cf., Dube, Rotello, & Heit, 2010 ; Trippas, Handley, & Verde, 2014 ), which we did not report given that they converged with the reported analyses. As a consequence, our confidence rating scale has a very low resolution, potentially negatively impacting the possibility of uncovering meaningful patterns.…”

Can cognitive psychological research on reasoning enhance the discussion around moral judgments?

“…Moreover, individuals usually only reason when the conclusion is unbelievable (i.e., they do not engage in reflection when the conclusion is believable). The conditional willingness to reason is called motivated reasoning (Kunda 1990 ) and results in increased accuracy when assessing the validity of unbelievable conclusions (Evans et al 1983 ; Trippas et al 2014 ). The interaction between believability and validity delivers an example for the intuition-deliberation trade-off.…”

The intersection between Descriptivism and Meliorism in reasoning research: further proposals in support of ‘soft normativism’

“…Moreover, it is generally indicated that there are correct solutions, as can be seen in the following instructions from a study by Morley et al (2004) : “This experiment is designed to find out how people solve logical problems … Please take your time and be sure that you have the logically correct answer before deciding” (p. 8, italics added for emphasis). Even the most recent reasoning papers continue to use phrases such as, “If you judge that the conclusion necessarily follows from the premises, you should answer ‘Valid,’ otherwise you should answer ‘Invalid’ …” ( Trippas et al, 2014 , p. 11). We suggest that without instructing participants that there is a correct or valid answer to a given problem it is unlikely that standard effects from the reasoning literature would arise.…”