Which theory explains behavior as a response to internal physiological needs?

• A. Drives
• B. Incentive Theory
• C. Yerkes-Dodson Law
• D. Maslow's Hierarchy of Needs

Answer: (A)

Motivation arising from internal bodily needs is the key idea here. Drive reduction theory says when a physiological need (like hunger or thirst) isn’t met, it creates an internal push or drive. This drive motivates behavior aimed at reducing the uncomfortable state and restoring balance (homeostasis). That’s why hunger leads to eating and thirst leads to drinking—the actions are driven by the body's need to bring things back to normal.

Incentive theory focuses on external rewards rather than internal states, so it wouldn’t explain why you’re driven to eat simply because you’re hungry. The Yerkes-Dodson law is about how arousal affects performance, not about internal needs creating motivation to act. Maslow’s hierarchy describes a progression of needs but isn’t the mechanism that explains behavior as a direct response to a current physiological deficiency.