Sijilmassi et al. present a detailed examination of how historical myths can facilitate coalition recruitment. While we agree with the authors that historical myths are an effective tool for coalition growth, we are not convinced that this is the primary reason for why historical myths have evolved culturally in the first place. In this commentary, we argue that it is difficult to trace social evolution in this domain, and that even a close fit between an evolved entity such as historical myths and an applied function such as coalition recruitment does not imply that the function acted as a critical evolutionary trigger. We submit an alternative explanation: The key function of historical myths is to reduce psychological uncertainty among individuals by providing cognitive and behavioral directions. As we argue below, this alternative explanation has the advantage of not having to assume social interaction patterns (e.g., why and how people are recruited into coalitions). The explanation is based on the well-established psychological finding that most individuals are rather intolerant of uncertainty and use heuristics, including in social alliances, to reduce uncertainty by eliminating alternatives. Historical myths may be such psychological rules of thumb that are specifically useful for eliminating cognitive and behavioral alternatives for the culture and its specific adaptations in which they survived.

There are prominent precedents that illustrate the complexity of social evolution and the difficulty of tracing the roots of some social adaptations. For example, several competing theories have been discussed to explain human crying (Vingerhoets & Bylsma, Reference Vingerhoets and Bylsma2014; Zickfeld & Grüning, Reference Zickfeld and Grüning2021). One account conceptualizes crying as a social function (e.g., Gračanin, Bylsma, & Vingerhoets, Reference Gračanin, Bylsma, Vingerhoets, Fernández-Dols and Russell2017; Vingerhoets, Ven, & Velden, Reference Vingerhoets, Ven and Velden2016), but even in the light of this theory it remains unclear which of the functions of crying observed today (e.g., tears as social glue or as a visual signal for help) drove the evolution of human crying. Other examples include the domestication of plants and animals (e.g., Smith, Reference Smith2015) and even the development of language (e.g., Burling, Reference Burling1986; Walker & Hamilton, Reference Walker and Hamilton2011). Similarly, historical myths may be an effective tool for recruiting people into a particular coalition, but the effectiveness of historical myths as such a tool does not require that they drove the development of historical myths in the first place. Instead, the fact that historical myths are so effective at recruiting coalitions may be a by-product of a more fundamental psychological mechanism of reducing individual uncertainty.

To explain the remarkable longevity of historical myths, we propose that these myths act as cognitive and behavioral orientations for individuals. Learning about one's ingroup's past provides a behavioral framework for the world that reduces the cognitive load of decision making by providing a set of options (e.g., whom to seek as partner or what core values to believe in) and excluding a wide range of alternatives (e.g., ineligible options for dating and mating or what beliefs culturally considered nonsensical). This view of how myths work is evidently meaningful when we consider the parallels with religious beliefs. According to the uncertainty-reduction hypothesis, religious beliefs help individuals tolerate an unpredictable world. Consistent with this hypothesis, Barber (Reference Barber2011) has shown across 137 countries that religious belief declines as key uncertainties (e.g., income security, economic development, and personal health) decrease. Similarly, historical myths may have evolved because they served a critical function for individuals in reducing experienced uncertainty by providing clear guidance on what to do and when.

The uncertainty-reducing function of myths can also (inadvertently) make them effective for coalition recruitment. In this respect, the uncertainty-reducing explanation is consistent with the design features of historical myths discussed by the authors. According to the present interpretation, myths communicate past experiences of one's own ingroup or of a new outgroup. In the former case, following the myth provides a sense of sharing of traits and customs with one's ingroup. In the latter case, following the directions of a myth affords a set of habits (e.g., certain values or behaviors) that can transform a current outgroup into a soon-to-be ingroup.

Similar to the function of coalitional recruitment, the present explanation does not depend on historical myths actually providing optimal guidance for decision making. Rather, the appeal of historical myths is that they reduce the uncertainty experienced by individuals by prescribing a set of rules in the form of morals and dos and don'ts (see, e.g., Grüning & Krueger, Reference Grüning and Krueger2023; Krueger & Grüning, Reference Krueger, Grüning, Forgas, Crano and Fiedler2021, Reference Krueger, Grüning, Forgas, Crano and Fiedler2023, Reference Krueger, Grüning and Edokimova2024). That is, myths that provide a set of guidelines for making reasonable, though not necessarily optimal, choices may be effective decision aids based on past ingroup experience. In other words, myths can function as clusters of social heuristics.

Sijilmassi et al.'s account of the utility of historical myths for coalitional recruitment is instructive about the effectiveness of historical myths in this application context. Historical myths can be functional recruitment tools for the ingroup. Still, we are wary of concluding that this function is the central reason for the evolution of historical myths. On a metatheoretical note, we argue that it is difficult, if not impossible, to identify which of the existing functions of an evolved entity triggered its evolution in the first place, especially for social entities like myths. A more individual-centered and simpler explanation might be that myths are a useful tool for learning from past experience which values and behaviors are more successful than others. Admittedly, it may well be that the combination of mutually reinforcing functions (also beyond the two present ones) has compensated for the evolution of historical myths.