Easy-fix attentional focus manipulation boosts the intuitive and deliberate use of base-rate information.

In addressing human reasoning biases, "easy-fix" attentional focus interventions have shown that we can prompt reasoners to align responses with logico-mathematical principles. The current study aimed to test the impact of such interventions on both intuitive and deliberate responses on base-rate items. Using a two-response paradigm, participants provided initial intuitive responses under time constraints and cognitive load, followed by deliberate responses. During the intervention, we used attentional focus manipulations with base-rate items that aimed to redirect participants' attention toward the "logical" base-rate cue (i.e., the logical intervention) or toward the "heuristic" descriptive cue (i.e., the heuristic intervention). The results indicate that the logical intervention led to improved alignment with logico-mathematical principles in both intuitive and deliberate responses, albeit with a modest effect size. Conversely, the heuristic intervention had no discernible impact on accuracy. This indicates that our attentional focus manipulation is more effective at getting reasoners to respect rather than to override base-rates.

Further advancing fast-and-slow theorizing.

The 34 commentaries on the target article span a broad range of interesting issues. I have organized my reply around five major themes that seemed to emerge: Remarks about the generalizability of the empirical findings, links with other models, necessary extensions, the utility of dual-process models, and more specific points. This allows me to clarify possible misconceptions and identify avenues for further advancement.

Advancing theorizing about fast-and-slow thinking.

Human reasoning is often conceived as an interplay between a more intuitive and deliberate thought process. In the last 50 years, influential fast-and-slow dual-process models that capitalize on this distinction have been used to account for numerous phenomena - from logical reasoning biases, over prosocial behavior, to moral decision making. The present paper clarifies that despite the popularity, critical assumptions are poorly conceived. My critique focuses on two interconnected foundational issues: the exclusivity and switch feature. The exclusivity feature refers to the tendency to conceive intuition and deliberation as generating unique responses such that one type of response is assumed to be beyond the capability of the fast-intuitive processing mode. I review the empirical evidence in key fields and show that there is no solid ground for such exclusivity. The switch feature concerns the mechanism by which a reasoner can decide to shift between more intuitive and deliberate processing. I present an overview of leading switch accounts and show that they are conceptually problematic - precisely because they presuppose exclusivity. I build on these insights to sketch the groundwork for a more viable dual-process architecture and illustrate how it can set a new research agenda to advance the field in the coming years.

Can a fast thinker be a good thinker? The neural correlates of base-rate neglect measured using a two-response paradigm.

Traditionally, it has been assumed that logical thinking requires deliberation. However, people can also make logical responses quickly, exhibiting logical intuitions. We examined the neural correlates of logical intuitions by administering base rate problems during fMRI scanning using a two-response paradigm where participants first responded quickly and then reflectively to problems that did or did not pit a normative response against an intuitively-cued stereotypical response (i.e., conflict vs. non-conflict problems). As predicted, participants were less likely to make judgments in accordance with base rates on conflict problems. Critically, in only 4% of cases did longer deliberation change an initially biased response to a normatively correct response. The fMRI data revealed that intuitively-made initial biased judgments nevertheless activate regions typically involved in cognitive control, executive functions and attention, including anterior, inferior, middle and superior frontal cortex, suggesting that even when errors are made, there might be very early awareness of conflict.

Think slow, then fast: Does repeated deliberation boost correct intuitive responding?

Influential studies on human thinking with the popular two-response paradigm typically ask participants to continuously alternate between intuitive ("fast") and deliberate ("slow") responding. One concern is that repeated deliberation in these studies will artificially boost the intuitive, "fast" reasoning performance. A recent alternative two-block paradigm therefore advised to present all fast trials in one block before the slow trials were presented. Here, we tested directly whether allowing people to repeatedly deliberate will boost their intuitive reasoning performance by manipulating the order of the fast and slow blocks. In each block, participants solved variants of the bat-and-ball problem. Maximum response time in fast blocks was 4 s and 25 s in the slow blocks. One group solved the fast trials before the slow trials, a second group solved the slow trials first, and a third mixed group alternated between slow and fast trials. Results showed that the order factor did not affect accuracy on the fast trials. This indicates that repeated deliberation does not boost people's intuitive reasoning performance.

Intuitive errors in learners' fraction understanding: A dual-process perspective on the natural number bias.

Although a good rational number understanding is very important, many learners struggle to understand fractions. Recent research attributes many of these difficulties to the natural number bias - the tendency to apply natural number features in rational number tasks where this is inappropriate. Previous correlational dual process studies found evidence for the intuitive nature of the natural number bias in learners' response latencies. However, the reported correlations do not ascertain the causality that is assumed in this ascription. In the present study we therefore experimentally elicited intuitive responses in a fraction comparison task in educated adults by restricting reaction time. Results show that the natural number bias has an intuitive character. Findings also indicate that the detection of conflict between the natural number-based answer and the correct answer seems to work at an intuitive level.

Rational rationalization and System 2.

In this commentary, I highlight the relevance of Cushman's target article for the popular dual-process framework of thinking. I point to the problematic characterization of rationalization in traditional dual-process models and suggest that in line with recent advances, Cushman's rational rationalization account offers a way out of the rationalization paradox.

The Reflective Mind: Examining Individual Differences in Susceptibility to Base Rate Neglect with fMRI.

Performance on heuristics and bias tasks has been shown to be susceptible to bias. In turn, susceptibility to bias varies as a function of individual differences in cognitive abilities (e.g., intelligence) and thinking styles (e.g., propensity for reflection). Using a classic task (i.e., lawyer-engineer problem), we conducted two experiments to examine the differential contributions of cognitive abilities versus thinking styles to performance. The results of Experiment 1 demonstrated that the Cognitive Reflection Test (CRT)-a well-established measure of reflective thinking-predicted performance on conflict problems (where base rates and intuition point in opposite directions), whereas STM predicted performance on nonconflict problems. Experiment 2 conducted in the fMRI scanner replicated this behavioral dissociation and enabled us to probe their neural correlates. As predicted, conflict problems were associated with greater activation in the ACC-a key region for conflict detection-even in cases when participants responded stereotypically. In participants with higher CRT scores, conflict problems were associated with greater activation in the posterior cingulate cortex (PCC), and activation in PCC covaried in relation to CRT scores during conflict problems. Also, CRT scores predicted activation in PCC in conflict problems (over and above nonconflict problems). Our results suggest that individual differences in reflective thinking as measured by CRT are related to brain activation in PCC-a region involved in regulating attention between external and internal foci. We discuss the implications of our findings in terms of PCC's possible involvement in switching from intuitive to analytic mode of thought.

Debiasing thinking among non-WEIRD reasoners.

Human reasoning has been shown to be biased in a variety of situations. While most studies have focused on samples of WEIRD participants (from Western Educated Industrialized Rich and Democratic societies), the sparse non-WEIRD data on the topic suggest an even stronger propensity for biased reasoning. This could be explained by a competence issue (people lack the ability to integrate logical knowledge into their reasoning) or a performance issue (people possess the logical knowledge but do not know it is relevant). We addressed this question using a debiasing paradigm with the base-rate task on a sample of non-industrialized people, the Himba of Namibia. After a short training, most participants were debiased, lending credence to the performance account. Debiasing was however to some extent boosted by schooling and living environment suggesting that competence also plays a role (in that more acquired knowledge allows for a higher training benefit). Results imply that debias interventions can be successfully employed to boost sound reasoning around the world.

Fast & slow decisions under risk: Intuition rather than deliberation drives advantageous choices.

Would you take a gamble with a 10% chance to gain $100 and a 90% chance to lose $10? Even though this gamble has a positive expected value, most people would avoid taking it given the high chance of losing money. Popular "fast-and-slow" dual process theories of risky decision making assume that to take expected value into account and avoid a loss aversion bias, people need to deliberate. In this paper we directly test whether reasoners can also consider expected value benefit intuitively, in the absence of deliberation. To do so, we presented participants with bets and lotteries in which they could choose between a risky expected-value-based choice and a safe loss averse option. We used a two-response paradigm where participants made two choices in every trial: an initial intuitive choice under time-pressure and cognitive load and a final choice without constraints where they could freely deliberate. Results showed that in most trials participants were loss averse, both in the intuitive and deliberate stages. However, when people opted for the expected-value-based choice after deliberating, they had predominantly already arrived at this choice intuitively. Additionally, loss averse participants often showed an intuitive sensitivity to expected value (as reflected in decreased confidence). Overall, these results suggest that deliberation is not the primary route for expected-value-based responding in risky decision making. Risky decisions may be better conceptualized as an interplay between different types of "fast" intuitions rather than between two different types of "fast" and "slow" thinking per se.

Adieu Bias: Debiasing Intuitions Among French Speakers.

Recent debiasing studies have shown that a short, plain-English explanation of the correct solution strategy can improve reasoning performance. However, these studies have predominantly focused on English-speaking populations, who were tested with problem contents designed for an English-speaking test environment. Here we explore whether the key findings of previous debiasing studies can be extended to native French speakers living in continental Europe (France). We ran a training session with a battery of three reasoning tasks (i.e., base-rate neglect, conjunction fallacy, and bat-and-ball) on 147 native French speakers. We used a two-response paradigm in which participants first gave an initial intuitive response, under time pressure and cognitive load, and then gave a final response after deliberation. Results showed a clear training effect, as early as the initial (intuitive) stage. Immediately after training, most participants solved the problems correctly, without the need for a deliberation process. The findings confirm that the intuitive debiasing training effect extends to native French speakers.

Low second-to-fourth digit ratio predicts indiscriminate social suspicion, not improved trustworthiness detection.

Testosterone administration appears to make individuals less trusting, and this effect has been interpreted as an adaptive adjustment of social suspicion, that improved the accuracy of trusting decisions. Here, we consider another possibility, namely that testosterone increases the subjective cost of being duped, decreasing the propensity to trust without improving the accuracy of trusting decisions. In line with this hypothesis, we show that second-to-fourth digit ratio (2D:4D, a proxy for effects of testosterone in the foetus) correlates with the propensity to trust, but not with the accuracy of trusting decisions. Trust game players (n = 144) trusted less when they had lower 2D:4D (high prenatal testosterone), but their ability to detect the strategy of other players was constant (and better than chance) across all levels of digit ratio. Our results suggest that early prenatal organizing effects of testosterone in the foetus might impair rather than boost economic outcomes, by promoting indiscriminate social suspicion.

Belief inhibition in children's reasoning: memory-based evidence.

Adult reasoning has been shown as mediated by the inhibition of intuitive beliefs that are in conflict with logic. The current study introduces a classic procedure from the memory field to investigate belief inhibition in 12- to 17-year-old reasoners. A lexical decision task was used to probe the memory accessibility of beliefs that were cued during thinking on syllogistic reasoning problems. Results indicated an impaired memory access for words associated with misleading beliefs that were cued during reasoning if syllogisms had been solved correctly. This finding supports the claim that even for younger reasoners, correct reasoning is mediated by inhibitory processing as soon as intuitive beliefs conflict with logical considerations.

Analytic Engagement and the Perils of Reframing the Dual- and Single-Process Models Debate.

In a previous article published in Perspectives, I questioned whether the debate between dual- and single-process models of thinking is empirically tractable and argued that psychological scientists should leave it behind. Dewey (this issue) suggests that by reframing the debate in cognitive-modeling terms, it might become tractable and consequential. More specifically, he proposes that focusing on the question of whether analytic engagement (i.e., the process by which additional resources are allocated to a reasoning problem) is discrete or continuous might allow us to settle the debate. Here I illustrate how this suggestion is likely to face the same tractability problems as the original defining-features approach that it is supposed to replace.

On Dual- and Single-Process Models of Thinking.

Popular dual-process models of thinking have long conceived intuition and deliberation as two qualitatively different processes. Single-process-model proponents claim that the difference is a matter of degree and not of kind. Psychologists have been debating the dual-process/single-process question for at least 30 years. In the present article, I argue that it is time to leave the debate behind. I present a critical evaluation of the key arguments and critiques and show that-contra both dual- and single-model proponents-there is currently no good evidence that allows one to decide the debate. Moreover, I clarify that even if the debate were to be solved, it would be irrelevant for psychologists because it does not advance the understanding of the processing mechanisms underlying human thinking.

Intuition rather than deliberation determines selfish and prosocial choices.

Human interactions often involve a choice between acting selfishly (in ones' own interest) and acting prosocially (in the interest of others). Fast and slow models of prosociality posit that people intuitively favor 1 of these choices (the selfish choice in some models, the prosocial choice in other models) and need to correct this intuition through deliberation to make the other choice. We present 7 studies that force us to reconsider this longstanding corrective dual-process view. Participants played various economic games in which they had to choose between a prosocial and a selfish option. We used a 2-response paradigm in which participants had to give their first, initial response under time pressure and cognitive load. Next, participants could take all the time they wanted to reflect on the problem and give a final response. This allowed us to identify the intuitively generated response that preceded the final response given after deliberation. Results consistently showed that both prosocial and selfish responses were predominantly made intuitively rather than after deliberate correction. Pace the deliberate correction view, the findings indicate that making prosocial and selfish choices does typically not rely on different types of reasoning modes (intuition vs. deliberation) but rather on different types of intuitions. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

From bias to sound intuiting: Boosting correct intuitive reasoning.

Although human thinking is often biased by erroneous intuitions, recent de-bias studies suggest that people's performance can be boosted by short training interventions, where the correct answers to reasoning problems are explained. However, the nature of this training effect remains unclear. Does training help participants correct erroneous intuitions through deliberation? Or does it help them develop correct intuitions? We addressed this issue in three studies, by focusing on the well-known Bat-and-Ball problem. We used a two-response paradigm in which participants first gave an initial intuitive response, under time pressure and cognitive load, and then gave a final response after deliberation. Studies 1 and 2 showed that not only did training boost performance, it did so as early as the intuitive stage. After training, most participants solved the problems correctly from the outset and no longer needed to correct an initial incorrect answer through deliberation. Study 3 indicated that this sound intuiting sustained over at least two months. The findings confirm that a short training can boost sound reasoning at an intuitive stage. We discuss key theoretical and applied implications.

Recognizing biased reasoning: Conflict detection during decision-making and decision-evaluation.

Although it is well established that our thinking can often be biased, the precise cognitive mechanisms underlying these biases are still debated. The present study builds on recent research showing that biased reasoners often seem aware that their reasoning is incorrect; they show signs of conflict detection. One important shortcoming in this research is that the conflict detection effect has only been studied with classic problem-solving tasks, requiring people to make a decision themselves. However, in many reasoning situations people are confronted with decisions already made by others. Therefore, the present study (N = 159) investigated whether conflict detection occurs not only during reasoning on problem-solving tasks (i.e., decision-making), but also on vignette tasks, requiring participants to evaluate decisions made by others. We analyzed participants' conflict detection sensitivity on confidence and response time measures. Results showed that conflict detection occurred during both decision-making and decision-evaluation, as indicated by a decreased confidence. The response time index appeared to be a less reliable measure of conflict detection on the novel tasks. These findings are very relevant for studying reasoning in contexts in which recognizing reasoning errors is important; for instance, in education where teachers have to give feedback on students' reasoning.

Feeling we're biased: autonomic arousal and reasoning conflict.

Human reasoning is often biased by intuitive beliefs. A key question is whether the bias results from a failure to detect that the intuitions conflict with logical considerations or from a failure to discard these tempting intuitions. The present study addressed this unresolved debate by focusing on conflict-related autonomic nervous system modulation during biased reasoning. Participants' skin conductance responses (SCRs) were monitored while they solved classic syllogisms in which a cued intuitive response could be inconsistent or consistent with the logical correct response. Results indicated that all reasoners showed increased SCRs when solving the inconsistent conflict problems. Experiment 2 validated that this autonomic arousal boost was absent when people were not engaged in an active reasoning task. The presence of a clear autonomic conflict response during reasoning lends credence to the idea that reasoners have a "gut" feeling that signals that their intuitive response is not logically warranted. Supplemental materials for this article may be downloaded from http://cabn.psychonomic-journals.org/content/supplemental.

The smart intuitor: Cognitive capacity predicts intuitive rather than deliberate thinking.

Cognitive capacity is commonly assumed to predict performance in classic reasoning tasks because people higher in cognitive capacity are believed to be better at deliberately correcting biasing erroneous intuitions. However, recent findings suggest that there can also be a positive correlation between cognitive capacity and correct intuitive thinking. Here we present results from 2 studies that directly contrasted whether cognitive capacity is more predictive of having correct intuitions or successful deliberate correction of an incorrect intuition. We used a two-response paradigm in which people were required to give a fast intuitive response under time pressure and cognitive load and afterwards were given the time to deliberate. We used a direction-of change analysis to check whether correct responses were generated intuitively or whether they resulted from deliberate correction (i.e., an initial incorrect-to-correct final response change). Results showed that although cognitive capacity was associated with the correction tendency (overall r = 0.22) it primarily predicted correct intuitive responding (overall r = 0.44). These findings force us to rethink the nature of sound reasoning and the role of cognitive capacity in reasoning. Rather than being good at deliberately correcting erroneous intuitions, smart reasoners simply seem to have more accurate intuitions.