Ethological psychology occupies a distinctive and generative position within the depth-psychology corpus, serving as the empirical bridge between instinct theory and the study of unconscious patterning. The literature treats ethology not as a rival paradigm but as a complementary methodology: where Jungian psychology examines the introverted, psychic manifestations of inherited behavioral templates, ethology maps their extroverted, observable expression in natural environments. The Jungian tradition, particularly through Fordham’s early appropriation of Tinbergen’s innate release mechanisms and Stevens’s sustained syntheses, claims that both disciplines are effectively studying the same archetypal phenomena from opposite poles. Panksepp’s affective neuroscience inherits the ethological legacy of Lorenz, Tinbergen, and von Frisch, situating the ‘closed programs’ of instinctual behavior as foundational to any adequate account of emotional life, while acknowledging that behaviorism and ethology were long adversarial before their convergence toward neuroscience. The neuro-ethological strand represented by Alcaro and Carta extends this synthesis toward psychotherapy, grounding the reflective mind’s evolution in instinctual substrates. Throughout the corpus, ethology supplies the naturalistic warrant for concepts—innate release mechanisms, fixed action patterns, ritualization, imprinting—that depth psychology deploys to explain archetypal activation, attachment behavior, and the signal function of affect. The central tension concerns the permissible degree of zoomorphic extrapolation: from Levine’s caution against uncritical animal-to-human inference to Campbell’s confident invocation of inherited neural structures, the corpus negotiates how far ethological findings illuminate the human psyche without reducing it.