Lew-Levy and Amir paint a vivid and well-evidenced picture of the rich peer cultures that exist cross-culturally in humans. This compelling exposition of the nature of cultural transmission in children adds an important piece to the puzzle of human childhood and how it contributes to human cultural evolution. We agree that the role of children in building and transmitting cultures has been undervalued. However, it is not yet clear that peer culture is a qualitatively different kind of culture from any other type of culture. For the purposes of their argument, Lew-Levy and Amir introduce a distinction between “peer culture” and “adult culture.” This dichotomization risks oversimplifying the richness in variation across “adult cultures” and obscuring similarities to peer culture in children. To more cleanly arbitrate potential differences between cultures in childhood and adulthood, it will be essential to articulate the structure of the underlying psychology involved and describe whether it changes across development. This approach can elucidate whether peer culture is truly distinct from adult cultures or one of several cultural variants within the broader scope of cultural evolution.

A first step is to situate peer cultures within the variability of adult cultures. Lew-Levy and Amir’s portrayal of a unitary adult culture tied to formal institutions risks glossing over the myriad subcultures and countercultures that exist outside of formal institutions (e.g., punk music counterculture, regional or ethnic subcultures; Lieske, Reference Lieske1993; Fox, Reference Fox1987), or societies with few formal institutions in general. It also overlooks adult cultures that may emerge at other points in the lifespan, such as dating, parenting, and possibly elderly cultures (e.g., Lin et al., Reference Lin, Mikolajczak, Keller, Akgun, Arikan, Aunola and Roskam2023). If one considers a broader view of culture among adults, it becomes harder to view peer culture as necessarily distinct from adult culture, but rather one of myriad kinds of culture that humans can create in different conditions and stages of life. While they describe some of the characteristics of peer culture, it is not clear from the target article whether these would emerge from distinct psychological or cultural-evolutionary processes, and if they do not, then what precisely distinguishes peer cultures from other subsets of human culture?

Therefore, a second essential step is to map the psychology of underwriting peer cultures. If the cognitive systems that build and maintain cultures undergo fundamental changes from childhood to adulthood, it stands to reason that they may produce peer cultures that are qualitatively different from adult cultures. The question then becomes: What are the cognitive differences between children and adults underpinning the creation and transmission of distinct cultures? Although Lew-Levy and Amir briefly discuss relevant aspects of cognitive development (section 7.3), this section is cursory and broad. While it is undoubtedly true that increased abilities for joint attention, self-regulation, social interactions, exploration, and language play important roles, the target article leaves the details implicit, and it is unclear whether developmental changes in those abilities would constitute a difference in kind or merely a difference in degree.

One key cognitive capacity to investigate is social learning, the driving force of human cumulative culture (e.g., Boyd & Richerson, Reference Boyd and Richerson1995; Henrich & McElreath, Reference Henrich and McElreath2003; Tomasello, Kruger, & Ratner, Reference Tomasello, Kruger and Ratner1993). Infants and children readily engage in social learning, imitating others’ actions in ways that vary in their fidelity to the model and selectivity for the models they imitate (see e.g., Gweon, Reference Gweon2021; Over & Carpenter, Reference Over and Carpenter2012) and, in some cases, the content they learn (e.g., Barrett & Broesch, Reference Barrett and Broesch2012; Wertz, Reference Wertz2019). These social learning “biases” reflect the complex underlying structure of social learning systems. Social learning biases are also present in adulthood and show similar selectivity for certain types of content (e.g., information pertinent to survival; Stubbersfield, Tehrani, & Flynn, Reference Stubbersfield, Tehrani and Flynn2015) and for learning from certain models (e.g., favoring information from prestigious individuals; Jiménez & Mesoudi, Reference Jiménez and Mesoudi2019; conforming to the majority/plurality; Morgan, et al., Reference Morgan, Rendell, Ehn, Hoppitt and Laland2012).

Is the psychology of social learning meaningfully different in children and adults? Pursuing this question can clarify whether children’s peer cultures are fundamentally different from adult cultures. One possibility is that the social learning psychology itself differs between children and adults. For example, perhaps there are biases present in childhood that are absent in adulthood (or vice versa). Alternatively, perhaps the social learning psychology remains qualitatively the same across development, but other related cognitive mechanisms differ, particularly capacities that would facilitate innovation. A potential candidate is artifact reasoning, which seems to undergo a shift during childhood such that younger children do not show functional fixedness when reasoning about artifacts, while older children and adults have difficulty overlooking the intended function of an artifact in order to use it in a novel way (German & Defeyter, Reference German and Defeyter2000). Another candidate is developing linguistic abilities, which famously narrow and become less flexible with age (e.g., Hakuta, Bialystok, & Wiley, Reference Hakuta, Bialystok and Wiley2003). Finally, it may also be the case that the same learning biases are at play in both child and adult cultural transmission, but operate differently owing to their interaction with cultural norms. For example, the tendency to copy prestigious individuals is well established, yet understandings of who exactly is prestigious and worth copying may vary with age. Prestige can be determined by direct observation of someone’s success or by learning which cues are important for signaling success (Jiménez & Mesoudi, Reference Jiménez and Mesoudi2019), but our degree of exposure to these cues will vary with age, as will what our cultural group or subgroup deems as success. As a result, Peppa Pig may seem prestigious to a 5-year-old, but not to his mother.

Lew-Levy and Amir make a convincing case for the importance of child peer cultures in human cultural evolution; however, what looks prima facie to be distinct may simply be one among the broad suite of subcultures in the human cultural tapestry. In order to make a clearer argument for the distinctness of child peer cultures, we argue that further elucidation of the distinct (or not) psychology underlying peer cultures is required.