Which term refers to a complex behavior that is rigidly patterned and unlearned within a species, such as a baby drinking milk?

• A. Drive Reduction Theory
• B. Arousal Theory
• C. Belief Perseverance
• D. Instinct Theory

Answer: (D)

An instinct is an inborn, fixed pattern of behavior that appears across a species and is not learned. Instinct theory uses this idea to explain complex actions that happen automatically, such as a baby sucking to feed. Because these behaviors are universal and emerge without practice, they fit an innate program rather than learned responses. In contrast, drive reduction theory centers on internal needs creating drives that push us to reduce physiological tension, and arousal theory explains behavior in terms of seeking an optimal level of stimulation. Belief perseverance is a cognitive bias about clinging to beliefs despite contrary evidence, not an innate behavior. So the term that captures the unlearned, species-wide pattern is instinct theory.