Motivation and Emotion
• Need or desire that
energizes and
directs behavior
• Instinct Theory: we
are motivated by our
inborn automated
• But instincts only
explain why we do a
small fraction of our
Click on the fish to watch it’s
instinctual behavior.
Drive Reduction Theory
• Our behavior is
motivated by
• Wants to maintain
• When we are not, we
have a need that
creates a drive.
• Primary versus
Secondary drives
• Homeostasis:
Tendency to
maintain a constant
internal state
Example: Brrrr it’s
cold…where is my coat?
• Incentive: +/environmental
stimulus that
motivates behavior
Arousal Theory
• We are
motivated to
seek an optimum
level of arousal.
• Yerkes-Dodson
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.
Quiz question #1
• Which theory would be most helpful for
explaining why people are motivated to watch
horror movies?
a. Instinct theory
b. Drive-reduction theory
c. Incentive theory
d. Arousal theory
Quiz question 2
• According to Maslow, our need for _____
must be met before we are prompted to
satisfy our need for _____.
a. food; love
b. Self-esteem; adequate clothing
c. Self-actualization; economic security
d. Political freedom; adequate housing
Motivation of HUNGER
Hunger is both physiological and
Body Chemistry
• Glucose
• The hormone insulin
converts glucose to
• When glucose levels
drop- hunger
Biological Basis of Hunger
• Hunger does NOT
come from our
It comes from our…
• Brain
What part of the
• The Hypothalamus
Lateral Hypothalamus
• When stimulated it
makes you hungry.
• When lesioned
(destroyed) you will
never be hungry again.
Ventromedial Hypothalamus
• When stimulated you
feel full.
• When lesioned you will
never feel full again.
Set Point Theory
• The hypothalamus
acts like a thermostat.
• Wants to maintain a
stable weight.
• Activate the lateral
when you diet and
activate the
ventromedial when you
start to gain weight.
• Leptin theory
Metabolic Rate
• The body’s base rate of energy expenditure
Example: Holocaust victims stabilized their
bodies at ¾ of their normal weight by reducing
their energy expenditure.
Taste Preferences
Food taste better and we chew less when we are
hungry (beginning of a meal).
Food tastes worse
and we chew more
when we are not
hungry (at the end of
the meal).
Its weird, the better the food tastes, the less
time we leave it in our mouths.
Culture and Hunger
Mice Wine
Fried Frog Legs
Criadillas- bull testicles.
Psychological Aspects of Hunger
• Internals versus
• The Garcia Effect
Anorexia Nervosa
• Starve themselves to below 85% of their
normal body weight.
• See themselves as fat.
• Vast majority are woman.
Click on the
woman to watch a
case study of an
Eating Disorders
Bulimia Nervosa
• Characterized by
binging (eating large
amounts of food)
and purging (getting
rid of the food).
• Severely overweight
to the point where it
causes health issues.
• Mostly eating habits
but some people are
predisposed towards
Click on the pictures to see
some case studies on obesity.
Quiz question
• When an organism’s weight falls below its set
point, the organism is likely to experience a(n)
________ in hunger and a(n) ________ in its
metabolic rate.
a. Increase; increase
b. Decrease; decrease
c. Increase; decrease
d. Decrease; increase

Motivation and Emotion