In the target article, De Neys argues that dual-process models are obsolete and empirically and conceptually problematic to explain human reasoning. The author claims that problem is the tendency to conceive fast-and-slow processes or intuition and deliberation as two separate processes producing unique responses. So, the core problem of dual-process models is to assume that fast-and-slow processes are based on exclusivity features. In contrast to these models, De Neys suggests the exclusivity and switch are two interconnected features of fast-and-slow processes. We agree with the author's idea, the classical distinction between fast and slow processes as separable and exclusive processes can be softened.

In literature, it has been demonstrated that the slow processes can gradually become flexible and context dependent (Fabio, Caprì, & Romano, Reference Fabio, Caprì and Romano2019). The term context refers to those perceptual features of the task setting that are not formally required for successful task performance, yet which may influence performance with practice based on contingencies with task-relevant information. Several studies (D'Angelo, Jiménez, Milliken, & Lupiáñez, Reference D'Angelo, Jiménez, Milliken and Lupiáñez2012, Reference D'Angelo, Milliken, Jiménez and Lupiáñez2013, Reference D'Angelo, Milliken, Jiménez and Lupiáñez2014; Fabio et al., Reference Fabio, Caprì and Romano2019; Ruitenberg, Abrahamse, De Kleine, & Verwey, Reference Ruitenberg, Abrahamse, De Kleine and Verwey2012a, Reference Ruitenberg, De Kleine, Van der Lubbe, Verwey and Abrahamse2012b, Reference Ruitenberg, Verwey and Abrahamse2015; Ruitenberg, Abrahamse, & Verwey, Reference Ruitenberg, Abrahamse and Verwey2013) have examined if the slow processes can become flexible through reliance on contextual features, indicating that, when a task requires the activation of both fast-and-slow processes, subjects can switch between both processes and context features facilitate this switching. Therefore, it is reasonable to assume that the fast-and-slow processes do not necessarily generate unique responses and they have not the exclusivity features, because the slow processes can become more flexible through the inclusion of context-specific features and subjects can operate a switch between these two processes. So, the idea that the exclusivity and switch are two interconnected features of fast-and-slow processes is in line with these researches.

As suggested by De Neys, and we agree with his idea, traditional dual-process models fail to explain a viable internal switch mechanism. De Neys proposes a more viable general model that can serve as theoretical groundwork to build future dual-process models. The author's working model focuses on four components: intuitive activation, uncertainty monitoring, deliberation, and feedback. In this model, the starting point are two intuitions that can generate a different response. This component represents an alternative and new point of view if it is compared to a dual-process model in which the starting point is one intuitive or deliberative process. Moreover, according to the working model intuitive responses occur through an automatization or learning process. During development, any response might initially activate exclusive deliberation but through experience and practice this response will become automatized. This point of view is in line with the theories of automatization, demonstrating that after much practice the subjects show significant improvement in performing a task that initially require deliberative processes (Caprì, Santoddì, & Fabio, Reference Caprì, Santoddì and Fabio2020; Fabio, Reference Fabio2009, Reference Fabio2017; Fabio & Caprì, Reference Fabio and Caprì2019; Shiffrin & Schneider, Reference Shiffrin and Schneider1977).

The second component of the De Neys's model is an uncertainty monitoring process, conceived as a mediator for access to the deliberative processes. According to the author, the uncertainty monitoring process calculates the strength difference between different activated intuitions, the more similar the activation strength and the higher the uncertainty will be. The argument on the role and functions of uncertainty monitoring process is very interesting. However, differently to De Neys's idea, we believe that it is not a problem if the uncertainty threshold is the same when there are two strong intuitions or two weak intuitions, this is correct because the uncertainty does not depend on the intensity of the two strengths. So, if both intuitions are weak or strong it is right to achieve that the uncertainty is strong.

The third component of the De Neys's model is the deliberation that comes from the strength of the different activated intuitions. Deliberation might generate a combination of response suppression, generation, justification, or additional processes, and not necessarily a decrease in uncertainty. Consequently, it could occur a feedback loop in which system 1 and system 2 interact. The feedback stage is the last component of the De Neys's model. We agree with the argument about the third and fourth components, but we propose a change of the schematic illustration of the working model's core components. In the De Neys's illustration the arrow of fourth component goes intuitive activation (first component), we think a circular architecture in which the arrow of the feedback (fourth component) should return to uncertainty stage, and if the uncertainty is decreased, the arrow of feedback goes toward intuition; whereas if it is increased, the arrow goes toward deliberation (Fig. 1).

Figure 1.

A schematic illustration of the working model.

Our suggestion on the change of direction of the arrow related to feedback stage is not a mere schematic suggestion, but it reflects a theoretical conceptualization of fast-and-slow processes as interconnected processes in which it is possible to switch between these and the uncertainty operate as mediator.

In conclusion, human performance might result from an interplay between fast and slow processing and these processes may be mediated by systems that evolve to satisfy the need for a decrease of uncertainty and operate in a complex environment.