Abstract We argue that under minimal thermodynamic and control-theoretic assumptions, metabolic constraints imply generative cognition. We formalize cognition as a resource-bounded controller of probability flows, where metabolic budgets define path-space divergence constraints. This reframes inference as a physically instantiated process governed by metabolic regulation, implying that progress in the cognitive sciences requires grounding cognitive models in nonequilibrium thermodynamics and dynamical systems.
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.
