Instinct refers to an innate, unlearned, and complex pattern of behavior characteristic of a species. These behaviors are genetically determined and appear fully formed without prior experience or training. They represent an inborn inclination that guides an organism towards particular actions, uniformly expressed within a species.
Core Characteristics of Instinctive Behavior
Instinctive behaviors are innate, meaning they are genetically determined and do not rely on learning or environmental experience. This inherent quality ensures the behavior is present from birth or emerges at a specific developmental stage. They are also stereotyped, performed in a consistent and predictable manner by all members of a species, showing little modification based on individual experience. Instinctive actions are typically triggered by a specific external cue, often called a “sign stimulus” or “releaser,” which initiates the complex behavioral sequence.
Distinguishing Instinct from Learned Behavior
Instinctive behavior stands in contrast to learned behavior, which is acquired and modified through an organism’s experiences. Instincts are hardwired into an animal’s genetic makeup, making them rigid and inflexible. A spider, for example, spins an intricate web without ever being taught, a complex sequence of actions dictated by its genetic programming.
Learned behaviors, conversely, develop through interaction with the environment, observation, or direct instruction. A dog learning to sit on command or a bird recognizing a new predator are examples shaped by experience and memory. While instincts are fixed, learned behaviors are adaptable, allowing an organism to adjust its actions to changing circumstances and varying among individuals.
Instinctive Behavior in the Animal Kingdom
The animal kingdom provides numerous examples of complex instinctive behaviors. A newly hatched cuckoo chick instinctively shoves other eggs or nestlings out of the nest, ensuring it receives all parental care. Sea turtle hatchlings instinctively orient themselves and move towards the ocean’s reflective light. Elaborate courtship dances by birds, such as the blue-footed booby, also represent species-specific instinctive displays.
Many of these actions are categorized as Fixed Action Patterns (FAPs), which are sequences of unchangeable acts that, once initiated by a specific stimulus, are carried through to completion. For example, a greylag goose will instinctively roll an egg back into its nest using its bill if it sees the egg outside, continuing the motion even if the egg is removed. The sight of the displaced egg serves as the sign stimulus, triggering this unalterable behavior.
The Question of Human Instinct
The presence of complex instincts in humans is a topic of scientific discussion, largely because human behavior is profoundly shaped by learning, culture, and individual experience. While it is debated whether humans exhibit complex “instincts” akin to those seen in other animals, humans do possess several innate behaviors. These are primarily observed as newborn reflexes, involuntary movements present from birth.
Examples include the rooting reflex, where a baby turns its head and opens its mouth when its cheek is stroked, searching for a nipple to feed. The grasp reflex causes an infant to tightly clench its fingers around an object placed in its palm. The Moro reflex, often called a startle reflex, involves a baby throwing back its head, extends its arms and legs, then pulling them back in response to a sudden sound or movement. Most complex human actions, however, are considered a sophisticated blend of these innate predispositions and extensive learned modifications.