Bard, Keller, and Leavens’s WILD approach fits well with the thinking of developmental psychologists who view ontogeny through the lens of evolution. Their recognition that organisms adapt to local environments, consistent with Darwin’s original characterization of fitness, makes it imperative that a wide range of human ecological contexts be sampled before declaring species-universal adaptive behaviors. And given the great diversity of humans’ living conditions and child-rearing practices (e.g., Keller, Reference Keller2017; Lancy, Reference Lancy2015), it would be surprising indeed if a single, narrowly defined set of behaviors reflected important social-cognition adaptations for infants and children in all cultures. Neural, psychological, and behavioral plasticity are well-recognized evolved features of Homo sapiens, particularly early in life (see Bjorklund, Reference Bjorklund2021; West-Eberhardt, Reference West-Eberhard2003). Such plasticity permits infants and children to develop psychologies to fit with local conditions (Keller, Reference Keller2017), all while developing adaptations that increase the likelihood of surviving and eventually becoming fully functioning members of their communities. Also consistent with the perspective of many evolutionarily-oriented developmental psychologists is Bard et al.’s proposal to examine social-cognitive development in humans’ close genetic relatives as a clue to the phylogenetic history of these proposed adaptations. This is consistent with Tomasello’s (Reference Tomasello2019, p. 6) statement that “if we wish to explain how uniquely human psychology is created, we must focus our attention on ontogeny, and especially on how great ape ontogeny in general has been transformed into human ontogeny in particular.”

These basic components of Bard et al.’s WILD approach make it clear that the specific behaviors identified by Shared Intentionality Theory (i.e., visual shared attention) and Attachment Theory (i.e., security of attachment) are restricted to the limited range of societies (exclusively WEIRD) from which most of the data have been collected. Thus, I agree with the central tenet of the WILD approach that data from non-WEIRD societies (and great apes experiencing different rearing conditions) must be sampled to have truly species-universal theories of core social-cognitive developmental adaptations. However, I do not believe Bard et al.’s methodological critique calls for rejecting the underlying mechanisms and adaptive functions proposed by Shared Intentionality and Attachment Theories. The authors seem to suggest revising psychological principles based on behavioral variations. However, in dynamic systems, the higher-level attractor (psychological principles), by definition, allows for lower-level variability (behavioral variations), depending on environmental context (e.g., Osei & Bjorklund, Reference Osei and Bjorklund2024).

With respect to Shared Intentionality Theory, I propose that the significance of both the behaviors identified in WEIRD (e.g., visual shared attention) and WILD (e.g., tactile behaviors) cultures – and even those observed in chimpanzees (see Bard et al., Reference Bard, Keller, Ross, Hewlett, Butler, Boysen and Matsuzawa2021) – reflect an evolved, underlying set of social-cognitive mechanisms that lead to understanding one’s self and others as intentional agents (to varying degrees), which serves as the foundation for all more advanced forms of social cognition (Bjorklund, Reference Bjorklund2021). Homo sapiens live in the widest habitat range of any mammal and display substantial cultural variability in child-rearing practices, making variability in the expression and development of important social-cognitive adaptations unsurprising (at least in retrospect). Acknowledging that different cultural and local environments produce different specific behaviors, I argue that all are governed by an evolved set of primary (skeletal) mechanisms or dispositions that become fleshed out with experience (Bjorklund, Ellis, & Rosenberg, Reference Bjorklund, Ellis, Rosenberg and Kail2007; Geary, Reference Geary2005). Children worldwide who inherit a species-typical genome and experience a species-typical environment (broadly defined) develop species-typical behavior and psychology (for Shared Intentionality Theory, an understanding of agency; for Attachment Theory, social-emotional relations with important conspecifics), although the specific behaviors and how such agency or attachment is expressed and develops vary with culture and experience.

Bard et al. are not the first theorists to consider important social-cognitive developmental mechanisms from a cross-cultural perspective. For example, with respect to attachment, Mesman and colleagues (Reference Mesman, van IJzendoorn, Sagi-Schwartz, Cassidy and Shaver2016) recognized the cultural diversity of attachment behaviors but suggested four assumptions of attachment theory that, they proposed, are found cross-culturally: (1) attachment is universal, with healthy infants becoming attached to one or more caregivers (universality hypothesis); (2) infants living in good family contexts and non-threatening environments develop a secure attachment with their main caregivers in most studied cultures (normativity hypothesis); (3) the cause of secure attachment in the vast majority of cultures depends primarily on caregivers’ sensitivity to infants’ attachment signals (sensitivity hypothesis); and (4) the establishment of a secure attachment with their principal caregivers has many positive effects for children’s development in a variety of domains (competence hypothesis). Mesman, van IJzendoorn, & Sagi-Schwartz’s (Reference Mesman, van IJzendoorn, Sagi-Schwartz, Cassidy and Shaver2016) caveat of “most cultures” in some of their assumptions may call into question their claim of universality, and I suspect that Bard and colleagues would not concur with all of their conclusions. Nonetheless, scholarship such as this indicates that cultural differences are not being ignored by some contemporary attachment theorists.

Thus, the behaviors observed by researchers in both WEIRD and WILD cultures likely represent underlying evolved adaptations, although researchers must recognize that different behaviors reflecting these adaptations will be observed in different cultural/local contexts. The fact that chimpanzees, by some definitions, also display forms of shared attention (or joint engagement to use Bard et al.’s (Reference Bard, Keller, Ross, Hewlett, Butler, Boysen and Matsuzawa2021) term), for example, and that how they express shared attention varies with their rearing environment (wild vs. captive vs. enculturated), suggests that they too have the neural/cognitive/behavioral plasticity to respond to variations in “parenting” and so likely did our common ancestor with chimpanzees. Similar arguments could be made for attachment.

As more data from WILD populations are collected, Shared Intentionality and Attachment Theories will likely need to be modified. Nonetheless, these theories in their current form remain solid conceptual anchors for understanding important aspects of human social-cognitive development that should gain even more explanatory power with the addition of WILD data.