AP Psychology · Lesson 3

Motivation and emotion

Know Know it

Motivation is a need or desire that energizes and directs behavior. Drive-reduction theory says a physical need creates a tense state, a drive, that pushes us to reduce it and return to homeostasis, a steady inner balance. Arousal theory says we seek an optimal level of arousal, which helps explain curiosity and thrill seeking. The Yerkes-Dodson law says performance is best at moderate arousal: easy tasks are done best at somewhat higher arousal and hard tasks at lower arousal. Incentives are outside rewards that pull us toward a goal.

Maslow's hierarchy of needs ranks needs from physiological and safety needs up through belonging and esteem to self-actualization; lower needs usually come first. Intrinsic motivation is doing something for its own sake; extrinsic motivation is doing it for a reward or to avoid punishment. In the overjustification effect, an expected reward for a task a person already enjoys lowers their own interest in it. Hunger is driven partly by hormones such as ghrelin, which rises when the stomach is empty, and leptin, which signals fat stores, and by the hypothalamus. Choices can create conflict: approach-approach (two good options), avoidance-avoidance (two bad ones) and approach-avoidance (one option with both good and bad sides).

An emotion has three parts: physical arousal, expressive behavior and conscious experience. The James-Lange theory says we feel an emotion after we notice our body's response, so we feel afraid because we tremble. The Cannon-Bard theory says the body's response and the feeling happen at the same time, independently. The two-factor theory (Schachter and Singer) says emotion is arousal plus a cognitive label taken from the situation. Appraisal views add that how we judge an event shapes what we feel.

Some facial expressions of basic emotions are recognized across cultures, but display rules, the norms a culture teaches about when and how to show feelings, shape what people show. The facial feedback hypothesis says our facial expressions can strengthen or change what we feel.

Trap Watch the order in emotion theories

The theories differ mainly in order. James-Lange puts the body first and the feeling second. Cannon-Bard has them happen together. Two-factor adds a step: the person looks to the situation to label the arousal. If a scenario shows someone reading the setting to decide what a racing heart means, that points to two-factor theory, not James-Lange.

Worked example Easy

After a long run on a hot day, Lena feels very thirsty and drinks water until the feeling goes away. Which theory fits her behavior?

  1. Optimal arousal theory of motivation
  2. Drive-reduction theoryAnswer
  3. Incentive theory
  4. Cannon-Bard theory

How to solve it

  1. Name the cause of the behavior: an inner physical need for water.
  2. Acting to reduce a need-driven tension is drive-reduction theory.

Why each choice is right or wrong

  • A. Incorrect. Optimal arousal theory explains seeking stimulation to reach a preferred level, not satisfying a physical need such as thirst.
  • B. Correct. Lena's need for water creates a drive, and drinking reduces it and restores her body's balance, which is drive-reduction theory.
  • C. Incorrect. Incentive theory explains being pulled by an outside reward, but Lena is pushed by an inner physical need.
  • D. Incorrect. Cannon-Bard theory explains how emotions arise, and Lena's thirst is a physical need, not an emotion.

Explain Explain it

Task verbs: explain, predict

To predict with the Yerkes-Dodson law, first decide whether the task is easy or hard for this person. Then compare their arousal with what that task needs: higher arousal can help on an easy or well-learned task, and the same arousal can hurt on a hard or new one. To explain an emotion theory, say what happened first and what the person used to decide what they felt.

Worked example Medium

At a surprise concert, Sami's heart starts racing. He looks around, sees the crowd cheering, and decides he is thrilled rather than nervous. Which theory best explains his emotion?

  1. James-Lange theory
  2. Cannon-Bard theory
  3. Two-factor theoryAnswer
  4. The facial feedback idea

How to solve it

  1. Find the two parts: a racing heart and a label taken from the cheering crowd.
  2. Arousal plus a cognitive label from the situation is the two-factor theory.

Why each choice is right or wrong

  • A. Incorrect. James-Lange theory says the body's response alone produces the feeling, but Sami uses the cheering crowd to decide what he feels.
  • B. Incorrect. Cannon-Bard theory says arousal and feeling happen at once and independently, but Sami's feeling depends on reading the scene.
  • C. Correct. Sami has arousal and then labels it as thrill using cues from the situation, which is the two-factor theory.
  • D. Incorrect. The facial feedback hypothesis is about expressions shaping feelings, and the scenario never mentions Sami's face.

Predict Your turn

Noor has played one piano piece hundreds of times. Elif is playing a piece she learned only this week. Both will perform for a large, loud audience that raises their arousal a lot. Use the Yerkes-Dodson law to predict how this high arousal will affect each player, and explain why.

Write it, then compare. Nothing you type here is saved or graded.

Compare with a model answer

A full answer does this

  • Predicts high arousal will help or not hurt Noor because her piece is well learned
  • Predicts high arousal will hurt Elif because her piece is new and hard for her

Model answer

Noor will likely play well, maybe even better than usual, because her piece is well practiced, an easy task for her, and the Yerkes-Dodson law says easy tasks are done best at higher arousal. Elif will likely play worse, because her piece is new and hard for her, and hard tasks are done best at lower arousal, so the loud audience pushes her past her best level.

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