What motivates behavior? What is hunger? How are needs prioritized?

 Instinct Theory  Drive Reduction Theory  Optimal Arousal Theory

Behaviors are automatic and do not require learning Fixed action patterns Adaptive value of behavioral tendencies  Aggression  Mating  Altruism

We are motivated to maintain homeostasis A drive is a psychological state that results from an imbalance Drives motivate us to do things that will move us closer to homeostasis  Primary Drives – eating, drinking  Secondary Drives – association of primary needs with other stimuli, e.g., money

We have an optimal level of arousal When arousal is below optimal, we are motivated to increase it When arousal is above optimal, we are motivated to decrease it Performance tends to be higher at moderate levels of arousal

Regulated by hypothalamus  Secretion of orexin stimulates appetite Monitoring of blood  Glucose level, regulated by pancreas (insulin) Cues from the stomach  Secretion of grehlin by stomach stimulates appetite

Genetic differences Learned associations  Garcia Effect Cultural preferences

Social norms about weight and eating Eating disorders  Anorexia Nervosa  Bulimia Nervosa

Maslow’s Hierarchy A way to categorize needs Easier to satisfy higher level needs when lower level needs have been met