Psychological essentialism is persistent across cultures, which suggests that it is a cognitive strategy that enhances biological fitness. If essentialist thinking were a product of natural selection, it was likely shaped by socio-cultural evolution to foster group cohesion, aid social navigation, and reinforce social structures that enhance survival. The emergence and persistence of essentialist thinking likely stem from the reciprocal interaction between socio-cultural influences and evolutionarily conserved neurobiological processes. According to evolutionary epistemology cognition is an adaptive product shaped by natural selection, incorporating epigenetics, developmental plasticity, niche construction, and cultural transmission. Within this framework, “essentializing” emerges as a context-dependent cognitive process that upholds social identity. Essentialist thinking, in turn, functions as a cognitive shortcut, allowing humans to categorize social groups based on perceived intrinsic essences. This perspective aligns with anthropological findings suggesting that the expansion of the neocortex in hominid evolution was at least partly driven by the cognitive demands of social living. Consequently, cognitive strategies may have been subject to selection pressures, refining essentialist heuristics and biases as tools for social navigation. From an ontogenetic perspective, I focus on three neurobiological mechanisms: attachment and social learning, neuronal recycling and exaptation, and inductive inference and cognitive efficiency.