AP® Psychology · Unit 4 · Topic 4.6
Drive Reduction and Homeostasis
Drive reduction theory says unmet biological needs create internal tension called a drive, which pushes you to act until balance, or homeostasis, is restored.
Your body likes to stay in a narrow comfortable range for things like water, food, and temperature. When you drift away from that range, say you haven't had water in hours, your body doesn't just register a fact. It generates discomfort, a drive, that feels urgent and personal. That tension pushes you to act: find water, drink it, and the discomfort fades. This is the whole engine of drive reduction theory. A need creates a drive, the drive motivates behavior, the behavior reduces the drive, and you're back at your set point, the ideal level the body is defending.
The feedback loop runs constantly, even for things you never consciously notice, like body temperature. Your hypothalamus acts like a thermostat: it monitors internal temperature against a set point near 98.6 Fahrenheit. Drift above that line and your body sweats and blood vessels widen to release heat. Drop below it and you shiver and blood vessels narrow to conserve heat. Each response is corrective, pushing the system back toward balance, then shutting off once the set point is restored. That's homeostasis: a self-regulating loop, not a one-time fix.
The theory explains thirst, hunger, and temperature well because those all involve a real physiological deficit being corrected. It breaks down for behaviors that add arousal instead of reducing it. Skydiving, loud concerts, horror movies: none of these resolve a bodily need. People seek them out because some level of stimulation itself feels rewarding, which is why psychologists added sensation seeking, the tendency to pursue novel and intense experiences, as a separate motivational force alongside drive reduction.
Key terms
- Drive
- An internal state of tension caused by an unmet physiological need that pushes an organism toward goal-directed action.
- Homeostasis
- The body's tendency to maintain a stable internal balance, such as steady temperature or fluid level.
- Set point
- The specific level, like a target temperature or hydration level, that the body works to maintain or return to.
- Drive reduction theory
- The idea that motivation arises from the desire to eliminate the discomfort of an unmet physiological need.
- Sensation seeking
- A tendency to pursue novel, intense, or arousing experiences, not explained by reducing a physiological deficit.
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End of topic.