Instinct

Lore & Background

Jean Henri Fabre is said to be the first to study small animals and insects, specializing in insect instincts. He considered instinct a linked set of behaviours performed unconsciously in response to external conditions. Fabre concluded that most animals cannot reason, observing that insects and wild birds repeated behaviours in novel situations without adjusting them. He labelled behaviours such as maternal instincts, metamorphosis, mimicry, molting, playing dead, and taxis as instinctive. Fabre believed instincts were fixed patterns that do not change, though he admitted exceptions could occur. His view opposed evolution, as he rejected that one species could evolve into another. He studied babies' facial expressions in response to tastes, concluding these were instinctive movements to avoid unpleasant emotions. Wundt believed instincts became innate through natural selection causing small changes in the nervous system over time. He used the terms unconscious processes, reflexive movements, and instinctive movements interchangeably. Sigmund Freud defined instincts as biological forces motivating individuals to satisfy needs, dividing them into life instincts (Eros) and death instincts (Thanatos). William McDougall held that instincts have associated specific emotions, later recommending the word 'propensity' for human innate abilities due to plasticity. John B. Watson approached instincts from a behaviorist perspective, arguing most human behavior is learned. Abraham Maslow argued humans no longer have instincts because we can override them. Konrad Lorenz and Nikolaas Tinbergen revived interest in innate behaviours in the 1950s, distinguishing instinct from learned behaviours.

Reader's Guide

The concept of instinct has evolved significantly from early theorists to modern understanding. Jean Henri Fabre's work on insect instincts established the idea of fixed action patterns, though his rejection of evolution limited his framework. Wilhelm Wundt connected instinct to natural selection and unconscious processes, while Sigmund Freud expanded the concept to include life and death instincts driving human behavior. William McDougall emphasized the link between instinct and emotion, later shifting to 'propensity' for human behaviour due to plasticity. John B. Watson's behaviorist perspective challenged instinct as a primary driver of human action, arguing most behaviour is learned. Abraham Maslow further questioned instinct in humans, claiming we can override innate drives. The 1950s work of Konrad Lorenz and Nikolaas Tinbergen revived interest in innate behaviours, distinguishing instinct from learning, as seen in imprinting studies. The term remains useful for animal behaviour but is debated for humans, reflecting ongoing nature–nurture discussions.

Did You Know?

• Jean Henri Fabre is said to be the first person to study small animals and insects, specializing in insect instincts.
• Konrad Lorenz famously had a goose imprint on his boots, after which the goose would follow whoever wore the boots.

Defining the Inborn Blueprint

Instinct represents the deep-seated biological wiring that drives a living organism toward a particular complex behaviour without any prior learning or experience. At its most basic level, this manifests as a fixed action pattern—a short to medium sequence of actions executed without variation in response to a clearly defined stimulus. Every animal, humans included, carries these inborn behavioural templates. A newly hatched sea turtle scurrying toward the ocean, a marsupial newborn climbing into its mother's pouch, the construction of nests, courtship displays, and escape responses all exemplify this category. Crucially, instinct must be separated from simple reflexes like pupil constriction in bright light or the knee-jerk response; those are single, straightforward reactions, whereas instincts are layered, multi-step programmes. Yet the inborn nature of an instinct does not make it rigid in every detail. A dog, for instance, can sharpen its listening through repeated practice even though the underlying drive is innate. The invariant core remains, but the execution can be refined by experience.

Fabre and the Fixed Pattern

Jean Henri Fabre, working in the late nineteenth and early twentieth centuries, is widely regarded as the first scholar to systematically study the instincts of small animals and insects beyond the avian world. He conceptualized instinct as a linked chain of behaviours an organism performs unconsciously in response to external conditions, and he insisted these chains were fixed patterns that did not bend to novel circumstances. His most cited demonstration involved several wasp species: when Fabre interfered with their prey-catching sequence, only a single species altered its routine, which he treated as an exception rather than evidence of flexibility. Fabre also catalogued maternal instincts, metamorphosis, mimicry, molting, playing dead, and taxis as instinctive because they bypassed reasoning. His observations led him to a sharp distinction between humans and other animals—most animals, in his view, simply could not reason, as insects and wild birds kept repeating the same behaviour even when it no longer served them in a new situation. This conviction that instincts are immutable placed Fabre in direct opposition to evolutionary theory; he rejected both the transformation of one species into another and the idea that human consciousness could emerge from the gradual evolution of unconscious traits.

Wundt and the Roots of Unconscious Drive

He treated unconscious processes—which he labelled instinctive movements and used interchangeably with reflexive movements—as the foundational building blocks from which consciousness is constructed. In one notable line of inquiry, Wundt observed the facial expressions infants made when exposed to sweet, sour, and bitter tastes. He interpreted those expressions as the babies' attempts to rid themselves of something unpleasant in their mouths, driven by an aversion to disagreeable emotions. Wundt grounded the origin of these instincts in natural selection: over generations, small modifications in the nervous system accumulated, producing hereditary drives that then generated the unconscious processes we observe. In his framework, what looks like an inborn reflex is actually the sediment of ancestral learning that benefited survival and became encoded in the organism's biology. By linking instinct to evolutionary change in neural architecture, Wundt offered a mechanistic account that contrasted sharply with Fabre's insistence on immutability.

From Freud to McDougall: The Human Instinct Question

The early twentieth century saw instinct become a central battleground in understanding human motivation. Sigmund Freud reframed instinct as biological forces that propel individuals to satisfy their needs, splitting them into life instincts (Eros), oriented toward survival, reproduction, and pleasure, and death instincts (Thanatos), linked to aggression and self-destruction. For Freud, these drives were the engines shaping personality and behaviour. Around the same period, William McDougall proposed a union of instinct and emotion, arguing that many instincts carry their own specific associated emotions. McDougall defined instincts as innate, inherited tendencies that steer behaviour in a particular direction, viewing them as the fundamental forces behind human motivation. Yet as research grew more rigorous and terminology tightened, instinct as a blanket explanation for human conduct fell out of favour.