Understanding the appeal of fiction requires a nuanced approach. For this reason, we greatly appreciate how the authors focused on imaginary worlds, avoiding the common pitfall of giving narrow explanations for the broad entirety of fiction. Overall, the theoretical account put forth is intriguing and plausible, and provides some logical predictions about when and by whom imaginary worlds are most likely to be appreciated. Unfortunately, the definition for imaginary worlds put forth is inconsistent in its exclusion of religious narratives and the rationale for doing so (e.g., the Epic of Gilgamesh), and appears circular in constraining these narratives to those that fit the hypothesis. Most problematically, however, the available empirical evidence to support the theory's predictions is absent and at times even contradictory.

In several instances, the evidence cited in support of empirical questions is non-empirical in nature, or unpublished and not available for examination or critique. As examples, the claim that exploration correlates with a preference for cognitive tasks is supported by an unpublished conference presentation (Hills & Stroup, Reference Hills and Stroup2004), and the assertion that sci-fi readers are more politically progressive is supported by what appears to be conjecture from a literary scholar (Besson, Reference Besson2021). Several other instances of non-empirical, theoretical evidence being cited in support of empirical claims occur throughout (e.g., regarding resource collection, cooperation and cheating, signalling cooperative partners; André, Baumard, & Boyer, Reference André, Baumard and Boyer2020; Boon-Falleur, Baumard, & André, Reference Boon-Falleur, Baumard and André2020; Mell, Baumard, & André, Reference Mell, Baumard and André2019; Singh, Reference Singh2019). Although it is laudable that the theory proposed generates testable empirical questions, the evidence cited in support of these empirical claims is largely unpublished or non-empirical in nature.

Moreover, some of the empirical evidence that is available contradicts the theory. The article rightfully points out that if exploration drives an appreciation for imaginary worlds, than the meta-trait Plasticity should predict this appreciation. Plasticity is indeed closely linked to exploration (Aluja, García Óscar, & García Luís, Reference Aluja, García and García Luís2003; DeYoung, Reference DeYoung2013) and a consistent predictor of related constructs like sensation-seeking and approach behaviours (Hirsh, DeYoung, & Peterson, Reference Hirsh, DeYoung and Peterson2009; Olson, Reference Olson2005). Importantly, Plasticity is equal parts Openness and Extraversion (DeYoung, Peterson, & Higgins, Reference DeYoung, Peterson and Higgins2002), with the dopaminergic system responsible for exploration reflected in the interaction between these two traits (Fischer, Lee, & Verzijden, Reference Fischer, Lee and Verzijden2018). The evolutionary framing of the target article requires that Extraversion positively predict the appeal of imaginary worlds, given the importance of spatial exploration for information-seeking in human evolution. In actuality, Extraversion is negatively correlated with an appreciation for imaginary worlds (Dubourg, Thouzeau, de Dampierre, & Baumard, Reference Dubourg, Thouzeau, de Dampierre and Baumard2021). This negative association is difficult to explain if exploration is truly responsible for a drive to consume imaginary worlds; it appears to be direct evidence against the theory.

That said, one possible explanation for this result is that Extraversion is most strongly tied to Plasticity in stressful environments. Extraversion's role in dopamine function and approach behaviours is strongest in the presence of climatic stress (Fischer et al., Reference Fischer, Lee and Verzijden2018). Unfortunately, this creates new problems as it implies that another main prediction of the theory should be reversed: imaginary worlds should be most appealing in stressful, unstable environments. This would be consistent with evidence that we explore when uncertainty is salient (DeYoung, Reference DeYoung2013; Hirsh, Mar, & Peterson, Reference Hirsh, Mar and Peterson2012; Robbins & Arnsten, Reference Robbins and Arnsten2009). But this makes the rise in popularity of these imaginary worlds difficult to explain, especially if the primary consumers are those whose lives are made stable by affluence (Dubourg & Baumard [D&B] target article). The available evidence indicates that it is exclusively Openness that explains an attraction to imaginary worlds (Dubourg et al., Reference Dubourg, Thouzeau, de Dampierre and Baumard2021), and not Plasticity or Extraversion. We suggest that this is a direct result of the distinct difference between real-world and imaginary exploration. The latter is tied rather obviously to cognitive exploration, supported by Openness, as opposed to real-world exploration, which is linked to Extraversion.

As a final consideration, the popularity of re-engaging with known imaginary worlds also seems inconsistent with the main proposal of the target article. The frequently referenced imaginary worlds – Star Wars, Lord of the Rings, Harry Potter – all have ardent fan followings. Fans of these stories consistently re-engage with these imaginary worlds. Some report re-reading a series every year (Goodreads, Reference Goodreadsn.d.) and others re-watch the movies in gruellingly long marathons (Wallis, Reference Wallis2020). If exploration is truly behind the popularity of these worlds, why re-visit them so often? “Re-consumption” is characterized by a foundational knowledge of the work and its components (Russell & Levy, Reference Russell and Levy2012), which makes it inconsistent with a drive to explore and gather information. Although the prevalence of re-engagement with imaginary worlds challenges the primary thesis of the target article, it actually fits rather well with the pattern of associations observed for Openness and Extraversion. The tendency to re-read is driven by Openness (Ministero, Green, Gabriel, & Valenti, Reference Ministero, Green, Gabriel and Valenti2021), which supports our proposal that cognitive exploration is responsible for the appeal of imaginary worlds. Extraversion does not predict the tendency to re-read, suggesting that neither the general exploratory preference represented by Plasticity, nor the spatial exploration manifested by Extraversion, can explain the appeal of imaginary worlds.

In closing, we share the interest and enthusiasm for probing why, how, and for whom imaginary worlds are so popular. The target article succeeds in bringing this topic some well-deserved attention, by way of a thoughtful, systematic, and generative theoretical account. Unfortunately, the available empirical evidence, and real-world phenomena surrounding the (re-)consumption of imaginary worlds, indicates that this theory requires revision or substitution.