What is the evolutionary function of cuteness? Research on cuteness originated with the study of juvenile morphology following Lorenz's Kindchenschema proposal, which identified specific cues of juvenility that reliably elicit a distinctive affective response. Because juvenile cues activate protective responses typically associated with vulnerability and distress (e.g., compassion, harm avoidance), cuteness has often been interpreted as an emotion whose primary function is protection. However, this leaves a key pattern unexplained: children are perceived as cutest not when they are helpless, but when they are sociable, curious, and eager to interact. More surprisingly, we also perceive adults as cute when they display not vulnerability, but naïveté, enthusiasm, and teachability. To solve this issue, we propose a developmental investment theory of cuteness, according to which cuteness is not merely a protection-eliciting mechanism but a motivational system that evolved to support prosocial investment in the development of inexperienced individuals. Crucially, this account expands the range of cues that elicit cuteness beyond juvenile morphology to include behavioral and cognitive signals of immaturity and learning potential. Drawing on evolutionary anthropology, cognitive neuroscience, developmental psychology and social sciences, we argue that cuteness identifies motivated but inexperienced individuals, and elicits not rescue, but teaching, guidance, and social play. This theory provides a better account of which traits elicit cuteness, what responses they provoke, and how cuteness is strategically deployed. It explains why cuteness can be attractive in romantic interactions, why modern, learning-rich environments foster an explosion of cuteness and why women disproportionately perform cuteness in patriarchal societies. Finally, we suggest that, over evolutionary time, this system may have contributed to the domestication of other species, and to the self-domestication of our own.
Interpersonal synchrony, such as dancing to a shared rhythm, elicits bonding and rewards, leading many to see it as a mechanism for group cohesion. Yet synchronized activities also reduce ingroup bias, rapidly bond strangers, flatten hierarchies and blur roles, and evoke trance states. Synchrony thus softens many boundaries that "groupishness" requires. Perhaps in consequence, cultural authorities frequently condemn expressive dance music rather than embracing it as a tool for social cohesion. Aiming to account for these multifarious features, this review integrates findings from cognitive motor science, biomusicology, and adjacent fields to synthesize the relaxed priors through synchrony (RePS) model. Highlighting synchrony's effects on high-level social predictive processing, RePS depicts the sensorimotor signals associated with beat perception and synchrony as lending precision to bottom-up prediction error at temporally granular (< 2-second) scales. Precision for abstract social priors is thereby reduced, inverting the social brain's characteristic "top-heaviness." With categorical beliefs about roles and groups no longer scaffolding coordination and joint action, local-timescale planning and processing evoke low psychological construal. Tighter links between motivation and reward facilitate disinhibited enjoyment orthogonal to status and group boundaries. In the entropic cognitive state that results, relaxed social priors are more easily revisable, enabling coordinated change and updating, as in ritual celebrations. This model affords rich opportunities for empirical testing and interdisciplinary theory-building. Overall, RePS explains why authorities frequently dislike synchrony, why dance plays centrally in social transitions such as weddings, and why rhythmic music is associated with trance. More than a bonding device, synchrony facilitates change.
The biases of WEIRD science need further correction beyond WILD. Specifically, humanity's million-year-old evolved, species-typical child-raising practices need to be recognized and utilized as baselines for species-normal child-raising practices, limiting the kind of local diversity considered species-typical. Third, considerations of what is considered to be species-normal outcomes should be guided by experiences of species-typical child-raising practices.
We were pleased to read the comments on our target article expressing views from diverse disciplines, including biology, philosophy, psychiatry, anthropology, and numerous branches of psychology (i.e., developmental, cultural, evolutionary, and comparative psychology). In this response, we discuss their ideas about routes to increasing inclusivity in theories of developmental psychology and present our disagreements with the few who argue that there is no need for change to theories. We highlight the commentators' broad agreement with the main themes of the WILD (Worldwide, In situ, Local, & Diverse) approach and the practical guide of 5 Steps to Inclusivity, and we consolidate commentators' views on infrastructural changes that are necessary to reach our collective goal of increasing inclusivity in theories of developmental psychology.
Bard et al.'s WILD framework calls for cultural inclusivity in developmental science. We argue for extending this framework to neurodiversity, emphasizing equifinality and individual differences. Including neurodivergent populations enriches developmental theory and avoids harm caused by neurotypical benchmarks. A truly inclusive science must recognize developmental pathways that vary by culture and neurotype as valid and meaningful.
We fully endorse the authors' aim and conclusions that we must move toward a deeper and more representative developmental science. We disagree with the authors' interpretation of the evidence to support their claim. We propose a more inclusive approach to science with a focus on development in action.
Childhood is a cultural project with shared goals, constant adaptation, and struggle; child well-being requires the engaged participation of a child in the cultural activities deemed desirable in that community. The evidence and conceptual frame of this paper show the remarkable varieties of childhoods and cultural contexts found around the world, which affect attachment and shared intention/coordinated joint engagement theories.
Bard et al. call for increased inclusivity in developmental science. In agreement with this need, we highlight the need to examine the origins of our developmental theories. We build on their work by demonstrating that a failure to examine the metaphysical commitments to culture within our theories can lead to erroneous assumptions as well as constraining research on development.
Inclusive global theories of child development require local researchers who spearhead research within their own communities. This means creating pathways for researchers from underrepresented contexts to lead projects, define priorities, and collaborate as equal partners, rather than merely act as data collectors. This capacity-building holds the promise of generating more accurate and equitable developmental science research.
Bard, Keller, and Leavens put a spotlight on the demographic makeup of participant samples in developmental psychology. These participants are generally Western, educated, industrialized, rich, and democratic, echoing a widespread problem in psychology. The authors advocate for an approach that is worldwide, in situ, local, and diverse (WILD). Here, we want to look at WILD work in the domain of navigation, which illustrates some of the challenges involved with the approach.
This commentary extends the WILD framework to societies undergoing rapid industrialization and globalization. We demonstrate how children in these societies form close attachments to extended kin and non-kin members, consistent with local cultural values and modern societal demands and in contrast to the core assumptions of attachment theory. These caregiving ecologies showcase the functional plasticity of the human developmental system.
Here, we highlight two key implications of adopting the WILD framework (Worldwide samples, study development In situ, focus on Local cultural practices and ethnotheories, and consider development as Diverse) and propose an extended version that addresses these considerations. Our extension (the acronym: "WILDER") introduces two additional components: the assessment of potential carry-over effects ("Experience") in small sample populations, where repeated testing of participants may be unavoidable; and testing multiple sub-groups ("Replication") within each population to capture within-group variation.
The application of the WILD research framework (Worldwide, In situ, Local, Diverse) to developmental psychology exposes further WEIRD biases. I suggest that Diversity must extend beyond Worldwide sampling to include within-nation variation and suggest that structural and cultural barriers maintaining WEIRD dominance can be mitigated through lightening bureaucratic loads, researcher reflexivity, and cross-disciplinary collaboration.
As Bard, Keller, and Leavens show, attachment theory does not account for the diversity of child-rearing practices around the world. However, the entrenched commitment to Bowlby's idea that the attachment system is a biological adaptation prevents attachment researchers from fully understanding the import of such diversity. I argue that this idea relies on a static and flawed view of evolution.
We advocate for decolonizing developmental theory beyond sample expansion. Using attachment theory as an example, we demonstrate how current theories misrepresent even Western populations, where allo-parental care is a necessity. We argue that focusing on adaptive challenges, not behavior, will support open-ended theories with universal relevance. This requires reflexivity, transparency, and centering indigenous methods prior to proposing any universal developmental mechanisms.
While Bard et al.'s WILD framework commendably calls for broader inclusivity in developmental science, it underestimates the challenges posed by migration. Migrant children's lives complicate the constructs of local and in situ, demanding their reconceptualization as fluid and multi-sited. Recognizing this complexity is important for advancing culturally robust developmental theories.
The authors dismiss two major developmental theories for lacking universal claims, but misrepresentations of attachment theory, joint attention, and sensitivity undermine this critique. Identifying behavioral universals often devolves into debates about exceptional cases and generalizability, and misses the more interesting questions of how behavioral diversity advances species' adaptive functions. Diversity exists, but it alone is not a developmental theory.
Crowd-sourced replication initiatives reveal that cultural differences in findings, while undoubtedly important in some cases, are often smaller and less systematic than assumed. This makes empirical testing, rather than presumption, exigent. The extent to which developmental psychology theories generalize across cultures is an empirical question, best answered via small- and large-scale collaborations between partner laboratories across the world.
Bard et al. rightly call out Western-centric bias to champion Worldwide, in-Situ, Local and Diverse developmental research. Yet this inclusivity must be grounded in evolutionary theory to model development. Comparative evidence strengthens accounts of shared intentionality and attachment. Integrating within-species variation through WILD with between-species variation engaging evolutionary perspectives will offer more robust explanations of universal and diverse developmental pathways.
