Are other great apes really inflexible?

Claims of a uniquely human institutional stance centers on our species’ flexibility, as animals’ capacities are proposed to be limited to a few categories like dominance and kinship, and are assumed to involve attributions of social roles as essentially immutable individual traits. We argue that at least our closest relatives, chimpanzees (Pan troglodytes), are more flexible than this characterization. Consider dominance hierarchies, a key example from the article. While animal dominance is often thought to reflect physical intimidation, chimpanzee hierarchies are substantially more fluid (de Waal, Reference de Waal1982; Muller, Wrangham, & Pilbeam, Reference Muller, Wrangham and Pilbeam2017). Dominant males can acquire rank in part through social support and may differ substantially in their use of aggressive versus affiliative strategies (Foster et al., Reference Foster, Gilby, Murray, Johnson, Wroblewski and Pusey2009; Muller & Mitani, Reference Muller and Mitani2005). As such, any fixed concept of “dominant” will not fully capture this role in chimpanzee groups.

Similarly, while we agree that kinship roles are often fairly ingrained, chimpanzee kin interactions are also context-dependent (Pusey, Reference Pusey1983; Walker & Pusey, Reference Walker and Pusey2020). For example, mothers tend to be more sociable when they have infant sons than daughters (Murray et al., Reference Murray, Lonsdorf, Stanton, Wellens, Miller, Goodall and Pusey2014). Moreover, while chimpanzee mothers overwhelmingly provide offspring care, younger siblings are sometimes “adopted” by older siblings following maternal death – even by males who would not normally exhibit such caretaking (Hobaiter et al., Reference Hobaiter, Schel, Langergraber and Zuberbühler2014; Reddy & Mitani, Reference Reddy and Mitani2019). This suggests that chimpanzees can sometimes fill “empty” institutional roles, even ones as seemingly predetermined as “mother.”

Finally, we consider a potentially overlooked proto-institution: social play. Play provides a meaningful point of continuity as it encompasses many of the sorts of leisure-based social institutions characterized as uniquely human (e.g., book clubs, sports leagues). Play is a crucial social behavior shown by juvenile and adult chimpanzees (Sabbi et al., Reference Sabbi, Kurilla, Monroe, Zhang, Menante, Cole, Otali, Kobusingye, Emery Thompson, Muller, Wrangham and Machanda2024; Samuni et al., Reference Samuni, Mielke, Crockford and Wittig2024), and the same individual may show either aggressive intent or signal playfulness through postures, facial expressions, and vocalizations. Moreover, play can change the “meanings” of objects: a stick may be a utensil when foraging, a weapon in an aggressive context, or a toy during play (Kahlenberg & Wrangham, Reference Kahlenberg and Wrangham2010; Watts, Reference Watts2007). In that sense, while animals’ overt institutional behaviors are obviously limited by their lack of language and material possessions, it is unclear whether the cognitive representations that allow for institutional flexibility may nonetheless be shared.

Are humans really that flexible?

We agree that humans can participate in a wide variety of institutions, ranging from coffee shops to universities to national governments. The target article proposes that humans can do so because we possess generative institutional representations. We argue that humans may be less cognitively flexible than assumed, and that this apparent variety may be mostly due to the variety of institutional content. This content may be generative, even while the underlying structure reflects strong commonalities: clubs sharing a passion for books, soccer, or Pokémon cards – or governing organizations of homeowners, cities, or nations – all share overlapping purposes (e.g., for socializing and leisure or for collective decision-making).

Work by Fiske (Reference Fiske1991) described in the target article synthesizes cross-cultural insights to propose that there are only three or four core types of social relations defining an individual’s roles within groups. For example, both a soccer league and a book club could follow a “communal sharing” or an “equality matching” principle. While there might be a myriad of ways in which these social relations manifest, the core structures are limited by strong boundary conditions. Similarly, while children seem to intuitively grasp these core social relations, they are also limited in the kinds of institutional structures they represent and create (Heck, Shutts, & Kinzler, Reference Heck, Shutts and Kinzler2022; Thomas, Reference Thomas2024), often emulating familiar social interactions (Harris, Reference Harris2021) rather than generating a wide range of arbitrary institutional structures.

Finally, while the human institutional stance might open doors to understanding and creating new institutional structures, we think much of the specific institutional practices described in the article could be due to historical events and cultural changes in technologies and social exchange. For example, many small-scale human societies lack formalized, temporally-enduring political institutions and rather organize informal leadership as needed (Boehm, Reference Boehm1999; Garfield, Syme, & Hagen, Reference Garfield, Syme and Hagen2020). Conversely, many institutions in postindustrial societies are shaped by the modern professionalization of these institutions and such historical changes may impact our psychological processes directly (Elias, Reference Elias1939; Foucault, Reference Foucault1977). Lastly, as readers may experience when filing tax returns or reading Kafka novels, intuitive theories of institutions can break down when trying to navigate institutional bureaucracies. For this reason, the wide range of current institutional structures should not be taken as direct evidence for a generative mental ability to comprehend these institutions.

What are they for? The functions of institutions

We emphasize that understanding the function of different institutional structures is critical, both for formal scientific theories and for people navigating their social world. The target article uses “function” to describe the task or goal of a particular role within an institutional structure, such as a barista brewing coffee or blending sugar-free iced-vanilla-protein matcha. We think the holistic purpose of the institution must also be considered: coffee shops brew coffee, but more broadly serve foraging and socializing functions. Many of the diverse institutions mentioned in the article may meet a quite limited number of needs, such as acquiring food, maintaining social bonds, or collective decision-making. While human social interactions may manifest in diverse ways in terms of the content of institutional structures, some animals also engage in group-level behaviors with parallel functions. We predict that the number of core institutional functions and their associated structures will be more limited, and more widely shared, in phylogeny and human history.