2. Instincts, Drives, and Hunger

3. Instincts  A pattern of behavior that is passed on through a species that can’t be unlearned  Building nests  Swimming upstream  Migration  Rooting

4. Drives  An aroused state of tension motivating a course of action  You are driven to fulfill physiological needs  Plan to get food, avoid pain, etc.

5. Drive-Reduction Theory  You have a need: food/water  You have a drive: hunger/thirst  You have a drive reducing behavior: eating/drinking

6. Incentives  Positive or negative environmental stimulus that motivates behavior  Physical attraction  Fear of disapproval  Scholarships  Failure

7. Ancil Keys  WWII Prison Camps  Fed enough to maintain initial weight, then cut food supplies in half  The men became obsessed with food  Nothing else was important

8. Physiology of Hunger  Walter Cannon – swallowed balloon to see if stomach contractions & hunger pangs were related  He had stomach contractions when he felt hungry

9. Body Chemistry and the Brain  The hypothalamus has two centers within that help control eating  Lateral hypothalamus (LH) brings on hunger  Ventromedial hypothalamus (VM) depresses hunger

10. Hormones and Pills  Scientists know of hormones and proteins that stimulate hunger and depress hunger (leptin, ghrelin, PPY)  Trying to find a miracle pill to work with these to regulate weight

11. Set Point Theory  Older theory  Body’s weight thermometer  If you eat too much, you body is supposed to stop at your set point  Same thing happens of you don’t eat enough

12. Basal Metabolic Rate  In order to maintain our bodies’ set point, our bodies need to maintain their basal metabolic rate  Too much food – fidget  Too little food – slow down body process

13. Eating Disorders  Cultures shape “beauty” - thin  Men/women views of what’s thin

14. Anorexia  Normal sized people become obsessed with losing weight  Continues to feel fat  Diets turn to starvation  At least 15% below normal body weight

15. Bulimia  Quick fix to lose weight  Binge eat high calorie foods followed by: –Vomiting –Laxative use –Fasting –Excessive exercise