Myers EXPLORING
PSYCHOLOGY
(6th Edition in Modules)
Module 26
Introduction to
Motivation: Hunger
James A. McCubbin, PhD
Clemson University
Worth Publishers
Motivation
 Motivation
 a need or desire that energizes
and directs behavior
 Instinct
 complex behavior that is rigidly
patterned throughout a species
and is unlearned
Motivation
 Drive-Reduction Theory
 the idea that a physiological need creates an
aroused tension state (a drive) that motivates
an organism to satisfy the need
Need
(e.g., for
food, water)
Drive
(hunger, thirst)
Drive-reducing
behaviors
(eating, drinking)
Motivation
 Homeostasis
 tendency to maintain a balanced or
constant internal state
 regulation of any aspect of body
chemistry around a particular level
 Incentive
 a positive or negative environmental
stimulus that motivates behavior
Maslow’s Hierarchy of
Needs
Self-actualization needs
Need to live up to one’s
fullest and unique potential
Esteem needs
Need for self-esteem,
achievement, competence,
and independence; need for
recognition and respect from others
Belongingness and love needs
Need to love and be loved, to belong
and be accepted; need to avoid
loneliness and alienation
Safety needs
Need to feel that the world is organized and
predictable; need to feel safe, secure, and stable
Physiological needs
Need to satisfy hunger and thirst
 begins at the
base with
physiological
needs that must
first be satisfied
 then higher-level
safety needs
become active
 then
psychological
needs become
active
Motivation-Hunger
 Stomach contractions accompany our feelings of hunger
Motivation-Hunger
 Glucose
 the form of sugar that circulates in
the blood
 provides the major source of
energy for body tissues
 when its level is low, we feel
hunger
Motivation-Hunger
 Set Point
 the point at which an individual’s
“weight thermostat” is supposedly set
 when the body falls below this weight,
an increase in hunger and a lowered
metabolic rate may act to restore the
lost weight
 Basal Metabolic Rate
 body’s base rate of energy expenditure
Motivation-Hunger
 The
hypothalamus
controls
eating and
other body
maintenance
functions
Motivation-Hunger
Eating Disorders
 Anorexia Nervosa
 when a normal-weight person diets and
becomes significantly (>15%) underweight,
yet, still feeling fat, continues to starve
 usually an adolescent female
 Bulimia Nervosa
 disorder characterized by episodes of
overeating, usually of high-calorie foods,
followed by vomiting, laxative use, fasting, or
excessive exercise
Anorexia
Anorexia was identified and
named in the 1870s, when it
appeared among affluent,
adolescent girls.
Obesity and Weight
Control
 Obesity and
body mass
index
Obesity and Weight
Control
 Obesity and mortality
2.8
Relative
risk of
death
2.6
2.4
2.2
2.0
1.8
1.6
1.4
1.2
1.0
0.8
0.6
18.5 18.5- 20.5- 22.0- 23.5- 25.0- 26.5- 28.0- 30.0- 32.0- 35.020.4 21.9 23.4 24.9 26.4 27.9 29.9 31.9 34.9 39.9
Men
Body-mass index (BM I)
Women
40
Weight Discrimination
7
6
 When women
applicants were
made to look
overweight,
subjects were less
willing to hire
Willingness
to hire scale 5
(from1:
definitely 4
not hire to
7: definitely 3
hire)
2
1
0
Women
Normal
Men
Overweight
Weight Control
 Effects of a severe diet
165
Metabolism:
Oxygen
consumption
in liters
per hour
26
160
25
155
24
150
23
145
22
140
21
Body
weight
in
kilograms
Caloric
intake
in
calories
per day
3000
2000
1000
0
8
16
Days
24 32
8
16
24
Days
32
8
16
24
Days
32
Weight Control
 Trading risks
Weight Control
 Obesity was
more
common
among those
who watched
the most
television
Skinfold fat
measure (mm) 32
30
28
26
24
22
20
<2
2-3
>4
Hours of television watched per day
in 1990s study
Boys
Girls
Weight Control
10
Weight 5
change
in pounds 0
 Most lost
weight is
regained
Starting
point
Normal trend for untreated obese
people: Gradually rising weight
-5
-10
After participation in behavioral
Program: Much of initial weight
Loss regained
-15
-20
Post
treatment
1
2
3
Years of follow-up
4
5