Conceptualizing cognitive flexibility: Singular versus modular view - Which one holds up?

Cognitive flexibility (CF) refers to the ability to adapt thinking and behavior to new or changing demands. However, conceptions of CF disagree on its structure, whether it is a uniform or a modular ability composed of different subtypes. Within the modular view, it has also been suggested that subtypes are organized in a hierarchical structure, although perspectives regarding this organization are inconsistent. The present study aimed to explore these structural and hierarchical views by comparing a one-factor model to a three-factor model that divides CF into task switching, switching sets, and stimulus-response mapping. Additionally, the study sought to test whether these subtypes are distinct and hierarchically organized, whereby task switching is initially assumed to be the most demanding, and stimulus-response mapping the least challenging. 235 participants (126 women) took part in the study, and performed nine different CF tasks, divided equally among the 3 subtypes. Confirmatory factor analysis indicated that the one-factor model fit was not adequate in contrast to the three-factor model. The three subtypes were distinct and displayed a hierarchical organization, with switching sets being the most demanding, followed by task switching, which did not differ significantly from stimulus-response mapping. These findings support the modular view of CF, suggesting that it comprises three distinct subtypes. However, the organization of these subtypes should be understood as dynamic, rather than fixed in terms of cognitive demand. This study contributes to a more nuanced understanding of CF as a multidimensional ability.