1. Motivation
Chapter 10

2. What is motivation?
A need or desire that energizes behavior and directs it towards a goal.

3. What motivates us? Five theories attempt to explain motivation:
Instinct Theory
Drive-Reduction Theory
Incentive Theory
Arousal Theory
Hierarchy of Needs

4. Instinct Theory
Instincts are complex behaviors patterns that are not learned.
Instinct Theory says we are motivated by our inborn automated behaviors.
But instincts only explain why we do a small fraction of our behaviors.

5. Drive-Reduction Theory
Our behavior is motivated by BIOLOGICAL NEEDS.
The aim of drive reduction is homeostasis, the maintenance of a steady internal state
When we are not in a homeostatic state, we have a need that creates a drive.
Examples
Shiver when your are cold to increase body temperature
Eat to reduce hunger-drive
Drink to reduce thirst-drive
OBJECTIVE 3| Explain how drive-reduction theory views human motivation.

6. Incentive
Where our needs push, incentives (positive or negative stimuli) pull us in reducing our drives.
Example
A food-deprived person who smells baking bread (incentive) feels a strong hunger drive.

7. Arousal Theory We are motivated to seek an optimum level of arousal.
Examples
Going to a horror movie
Riding a roller-coaster
Yerkes-Dodson Law says we perform better under increased levels of arousal (stress), but only up to a certain point…

8. Maslow’s Hierarchy of Needs
Abraham Maslow said we are motivated by needs, and all needs are not created equal.
We are driven to satisfy the lower level needs first.

9. Biological Basis of Hunger
Hunger does not come from our stomach.
It comes from our brain
Researchers removed rat stomachs, connected the esophagus to the small intestines, and the rats still felt hungry (ate food).
What part of the brain?
The Hypothalamus

10. Ventromedial Hypothalamus
Lateral Hypothalamus
Ventromedial Hypothalamus
When stimulated it makes you hungry.
When lesioned (destroyed) you will never be hungry again.
When stimulated you feel full.
When lesioned you will never feel full again.

11. Hypothalamus & Hormones
The hypothalamus monitors a number of hormones that are related to hunger.
Hormone
Tissue
Response
Orexin increase
Hypothalamus
Increases hunger
Ghrelin increase
Stomach
Insulin increase
Pancreas
Leptin increase
Fat/Adipose cells
Decreases hunger

12. Set Point Theory The hypothalamus acts like a thermostat.
Wants to maintain a stable weight.
Activates the lateral when you diet and activates the ventromedial when you start to gain weight.
Monitors fat

13. Obesity
Severely overweight to the point where it causes health issues.
Due to both nature and nurture.

14. Body Mass Index (BMI) Weight divided by height, squared
BMI of is overweight
BMI of over 30 is obese
Problems using BMI?
Body fat = fat weight divide by total weight
Women – Above 32% is obese
Men – Above 25% is obese

15. Eating Disorders Anorexia Nervosa
A disorder in which a normal-weight person (usually an adolescent woman) continuously loses weight but still feels overweight.
Starve themselves to below 85% of their normal body weight.

16. Eating Disorders Bulimia Nervosa:
A disorder characterized by episodes of overeating, usually high-calorie foods, (binging) followed by vomiting, using laxatives, fasting, or excessive exercise (purging).

17. Eating Disorders Binge Eating Disorder (BED):
A disorder characterized by recurrent episodes of overeating, usually high- calorie foods, (binging).