Other Minds, Other Compressions A Comparative ACAT Analysis of Non-Human Cognition, Consciousness, and the Spectrum of Mind An Application of Adaptive Compression Advantage Theory (ACAT)

Comparative cognition research has documented remarkable cognitive abilities across non-human species—tool use in corvids, self-recognition in dolphins, planning in great apes, metacognition in monkeys, problem-solving in octopuses—without a unified framework for understanding what these abilities share or how they differ from human cognition. This paper applies the Adaptive Compression Advantage Theory (ACAT; Murata, 2026) and its consciousness framework (Murata, 2026g) to provide a comparative taxonomy of non-human minds based on compression architecture. We characterize each major cognitive lineage by its α(d) profile (which environmental dimensions it compresses efficiently), its θ_c range (how selective its compression is), and its self-model complexity (the degree to which it satisfies the recursive-compression requirement for consciousness). We derive that: (1) animal cognition is not a single hierarchy from “less intelligent” to “more intelligent” but a multi-dimensional space of different compression specializations; (2) cephalopod cognition represents a radically alien compression architecture—distributed, non-centralized, embodied—that achieves sophisticated environmental compression through mechanisms fundamentally different from vertebrate brains; (3) social species show elevated α_social not as a luxury but as a survival-critical compression dimension; (4) the threshold for consciousness (recursive compression with self-model) has been crossed independently in at least four lineages (great apes, cetaceans, elephants, corvids); and (5) insect cognition, despite minimal neural hardware, achieves remarkable compression efficiency through architectural specialization rather than general capacity. The framework replaces the anthropocentric question “how intelligent is this animal?” with the precise question “what does this animal compress, and how?” Ten testable predictions are generated. Keywords: comparative cognition, animal intelligence, consciousness, ACAT, compression, cephalopods, corvids, cetaceans, primates, insects, self-model, theory of mind, tool use, social cognition, embodied cognitio