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Theories of Motivation
Hunger Motivation
Eating Disorders
Intro Psych
Module 26
Mar 31-Apr 5, 2010
Class #27-29
Motivation

The underlying processes that initiate, direct
and sustain behavior in order to satisfy
physiological and psychological needs or
wants
Theories of Motivation




Instinct Theory
Drive Reduction Theory
Arousal Theory
 Optimal Level Hypothesis
Incentive Theory
Instinct Theory

Instinct


Complex unlearned response triggered by a stimulus or
complex stimulus
Do humans have instincts?


Early Darwinian Theory (1800’s) proposed the idea of
instinct, arising from genetic endowment
William James (1890) proposed an instinct theory in
humans

Instincts were goal directed predispositions to behavior
Instinct Theory

Paradox in Psychology:


As others were showing that animal behavior
could be modified by learning (Thorndike),
James was proposing that much of human
behavior was unlearned
William McDougall (1908) followed…

Suggested their were 18 instincts
Instinct Theory

McDougall (1908) theorized that
motivated behaviors are instinctual:



Unlearned
Uniform in expression (do not change with
practice)
Universal (all members of a species show the
same behavior)
Too many limitations…

By 1924 instinct theory was becoming
obsolete as there were several criticisms:

Too many instincts


Researchers came up with 5759 of them
Logic was circular

i.e. the only evidence that an instinct exists was the
behavior it supposedly explained
 He’s an “overachiever” because he’s “hard-working”
 She’s “hard-working” because she’s an “overachiever”

Just meaningless labels with no
explanations
Drive Reduction Theory
(Hull, 1943)

Supporters of this theory believe that
when a need requires satisfaction, it
produces drives

These are tensions that energize behavior in
order to satisfy a need
 Thirst and hunger are, for instance, drives for
satisfying the needs of eating and drinking,
respectively
Drive Reduction Theory

Drives have been generally established
as primary and secondary…



Primary drives satisfy biological needs and must be fulfilled
in order to survive
Homeostasis is the motivational phenomenon for primary
drives that preserves our internal equilibrium. This is true,
for example, for hunger or thirst
Secondary drives satisfy needs that are not crucial to a
person's life
Criticism

Critics felt that this theory was
inadequate in explaining secondary
drives
Arousal Theories

Optimal Level Hypothesis
Optimum Arousal Theory:
Hebb (1955) and Zuckerman (1984)
This theory argues that we all have optimal
levels of stimulation that we try to
maintain…
 Optimal Level Hypothesis




we seek an optimal level of arousal
too little stimulation, we seek an increase
too much, we seek to decrease
Eysenck (1967)

ExtraversionIntroversion
 Introverts were overaroused individuals
therefore they try to
keep stimulation to a
minimum
 Extroverts were underaroused individuals,
therefore they tried to
increase stimulation
Eysenck (1967)
 Cortical

Arousal Differences
Eysenck suggests that the difference
between introverts and extroverts depends
on the ascending reticular activating system
(ARAS)
 Causes introverts to be “stimulus shy”
 Causes extroverts to be “stimulus
hungry”
Cortical Arousal Differences

Geen (1984)

Introverts and extraverts choose different levels
of stimulation, but equivalent in arousal under
chosen stimulation


Extroverts chose to hear louder noises than introverts
After put in their chosen environment their HR’s are the
same
 This seems to suggest that being at their preferred level
of stimulation results in the same overall level of arousal
for both groups
Geen (1984)

Researcher tested four other groups:




Introverts placed in environment that other
introverts had chosen (II)
Introverts placed in environment that extroverts
had chosen (IE)
Extroverts placed in environment that other
extroverts had chosen (EE)
Extroverts placed in environment that introverts
had chosen (EI)
Geen (1984)
II = similar HR as free choice introverts
 IE = higher HR than free choice
introverts when forced to listen to
extroverts’ noise
 EE = similar HR as free choice
extroverts
 EI = lower HR than free choice
extraverts when forced to listen to
introverts’ noise

Geen (1984)

Performance on a learning task was also
affected:


Introverts did best in introvert-selected
environment
Extraverts did better in extravert-selected
environment
 Practical implications:
 Roommates?
 Mate Selection?
Does it explain the psychopathic
behaviors???

Serial killer
Criticism of Optimum Arousal Theories

People differ greatly in the optimal level of
arousal they seek…

These theories do not explain why
Incentive Theory

Viewpoint on motivation that is different than
instinct, drive , and arousal theories
 Suggests that behavior is pulled rather than
pushed…


Emphasizes the role of environmental stimuli that can
motivate behavior by pulling people toward them rather
than pushing people to satisfy a need (as in the drivereduction theory)
Suggesting that people act to obtain positive incentives
and avoid negative incentives
 Explains secondary drives much better than
drive-reduction theory
Criticism

Some behaviors seem to be pushed as well
Abraham Maslow
(1908-1970)





Born in Brooklyn, NY
His parents were uneducated
Jewish immigrants from Russia
Hoping for the best for their
children – they pushed them
hard towards education
He became very lonely as a
youth and found his refuge in
books
To satisfy his parents, he
entered law school at CCNY and
then Cornell
Abraham Maslow


Against his parents wishes, he married his first
cousin and moved with her to Wisconsin where he
became interested in psychology and gets his BA in
1930, MA in 1931, and Ph.D. in 1934 at the Univ. of
Wisconsin
In 1935, he returns to NY and works with Thorndike
at Columbia and eventually begins teaching fulltime at Brooklyn College and then becomes chair of
psych department at Brandeis where he begins his
crusade for humanistic psychology
Maslow’s Hierarchy of Needs (1970)

Abraham Maslow proposed that there are
five levels of motives, or needs, arranged in
a hierarchy:






Physiological
Safety
Belongingness and love
Esteem
Self-actualization
We must satisfy needs or motives low on the
hierarchy before we are motivated to satisfy
needs at the next level
Physiological Needs


Physiological needs are basic,
instinctual needs for air, food,
water, and sex, among
others. These needs must be
at least partially met in order
to ascend the hierarchy.
These needs can also be
arranged in their own
hierarchy.
Safety Needs

Safety needs include
things such as shelter,
security, and protection
from physical and
emotional harm.
Belonging Needs

These needs are met by
having meaningful
relationships, such as
significant others, friends
and children
Esteem Needs



This level has two sublevels
Low esteem needs are the
needs for the respect of
others – need for
recognition, etc.
Higher esteem needs are
the needs for self respect –
to achieve, to be
competent, to be
independent, etc.
Self Actualization

Self actualization involves
becoming the most
complete person that you
can be – your full potential
Criticisms
Some critics felt that it is possible to skip
levels
 Others felt that they could not be applied
universally

Theories of Hunger Motivation
What triggers our motivation to eat?

Internal Factors





External Factors


An empty stomach?
Body Chemistry
Hypothalamus
Set Point Theory
Externality Hypothesis
Other Factors



Emotion
Habit
Attention
Internal Factors

An empty stomach?
 Early researchers thought that hunger pangs were
important - caused by contraction of stomach
 Cannon and Washburn (1912) tested the
hypothesis that the contraction of the stomach is the
cue to start eating
 Tested this by having Washburn swallow a balloon
and measuring contractions of the stomach by
looking at contractions of the balloon (changes in air
pressure go out stomach via tube to measuring
device)
An empty stomach?

Tsang (1938)


Removed rats stomachs and attached their
esophagus to their small intestine
They still displayed actions associated with
hunger
Body Chemistry

Blood Glucose

This is a simple sugar used by most cells in the body for
energy - most food ultimately gets converted to blood
glucose


Decreasing blood glucose levels  sense of hunger
Insulin

This is a hormone that increases the flow of glucose into
body cells, diminishing the amount of glucose in the blood
by converting it into stored fat

Decreasing blood glucose levels  sense of hunger
Body Chemistry

Glucagon


This hormone helps convert stored energy
supplies (stored fat) back into blood glucose
Increasing blood glucose levels  hunger decreases
Lesions of Hypothalamus

The destruction or stimulation of the
lateral and ventromedial areas causes
animals to ravenously decrease or
increase their weight

See picture on page 375 for example of
increase
Set Point Theory

Set point is the weight that your body
wants to be…


It is a self-regulatory system that maintains your
body weight
If you starve yourself the hypothalamus activates
compensatory mechanisms, your metabolism
slows so that energy stores are used more
sparingly and the amount of insulin that is
produced increases so that more of the food that
you take in remains as fat (this makes it possible
to maintain weight on a meager diet)
What triggers our motivation to eat?

External Incentives
 Rodin (1981)
 Like Pavlov’s dogs people learn to salivate in anticipation
of appealing foods

Externality Hypothesis (Schacter, 1978)
 Did research on obese humans
 They argue that the difference between obese and normal
weight subjects is that the obese are overly responsive to
external stimuli (cues for eating)
Externality Hypothesis



VMH-lesioned rats and obese humans are similar in
interesting ways:

Both are more "finicky" than controls. Both are less
willing to work for food

VMH-lesioned rats don't eat as much of a bad tasting
food as do control rats

Obese humans don't drink as much of a bad-tasting milk
shake as do control humans
VMH-lesioned rats don't bar-press for food on "lean"
schedules as readily as do the control rats
Obese humans eat fewer peanuts than do control humans if
they have to shell them, but more if they don't have to do
this work
Externality Hypothesis

These findings support Schacter's conclusion
that both VMH-lesioned rats and obese humans are
more sensitive to external cues related to food than to
the internal cues provided by their bodies.


Obese humans are more likely to eat more when they are
misled into thinking it's lunchtime than are control humans again evidence of the influence of external cues
Social Factor is another external cue

Eating around others often increases food intake
Other Factors
 Emotion


Habit


Depressed people may eat too much or too little
Meal time - ancient Romans only ate two meals
a day. We eat three - if we miss a meal, we feel
hungry at that meal time
Attention

Awareness vs. non-awareness
Eating Disorders
Obesity
 Anorexia Nervosa
 Bulimia Nervosa

Obesity

Weight which is 20-40% above the normal
standard for a person’s height (BMI over 30
kg/m2)



Rates of obesity are climbing and have risen from
12 to 20 percent of the population since 1991.
An ominous statistic which indicates that the
epidemic of obesity may get even worse is
that the percentage of children and adolescents
who are obese has doubled in the last 20 years
Why is this happening?
Basal Metabolic Rate

Basal metabolic rate (BMR) is the amount of
energy expended while at rest in a neutrally
temperate environment, in the post-absorptive
state (meaning that the digestive system is
inactive, which requires about twelve hours of
fasting in humans).



If you've noticed that every year, it becomes harder to
eat whatever you want and stay slim, you've also
learnt that your BMR decreases as you age. Likewise,
depriving yourself of food in hopes of losing weight
also decreases your BMR, a foil to your intentions.
M > W (more muscle)
Exercise increases BMR
Obesity



Weight which is 20-40%
above the normal
standard for a person’s
height
Rates of obesity are
climbing and have risen
from 12 to 20 percent of
the population since
1991.
Why is this
happening?
Obesity

Why do some people
become seriously
overweight?



Emotional problems
 Depression
 Anxiety
Sedentary lifestyle
 Too much TV and not
enough exercise
Genetics
 Higher set point
What factors help prevent obesity?


Preventing obesity must begin in
childhood
 Breastfed children less obesity
 Encouraging children to
exercise and eat healthy foods
 don’t use “special food” as a
reward – Stanek et al. (1990)
 children tend to be more
interested in a “forbidden food”
–– Mennella et al. (2001)
Limiting television watching
 Problem with adult modeling,
increase consumption of snacks
low in nutrients and watching
TV during meals increase
consumption of salty snacks
and pop and less fruit and
vegetables – Goldberg et al.
(2001)
 Many ads have low-nutrient
beverages and sweets – Story
and Faulkner (1990)
How is obesity treated?
 Fad
Diets
Exaggerated claims based on false
theories
 Potentially harmful


Weight Cycling


Set point theory?
Psychological ramification
Weight Cycling
Psychology of Weight
Cycling
How is obesity treated?

Eating less and eating smarter


Meals in US – much bigger portions than
elsewhere
Physical Activity - Increasing exercise


Activity and BMR-Eating
activity
increases BMR
less
Activity and appetite control





energy released from stores (plasma glucose normal)
digestive functions are suppressed
setting short-term goals
reminders or prompts
making behavior fit into daily schedule/ routine
How is obesity treated?

Operant conditioning approaches




Make small changes to behavior
Having the support of family members, and
friends – social support
Other self-control approaches
Behavior and Attitude
stimuli

  behavior   consequence
Awareness of behavior

why do I eat, when, where
Anorexia
Anorexia Nervosa

Anorexia Nervosa
 Self-starvation and severe weight loss
 Usually starts as an innocent diet that went out
of control
 They eat less and exercise more
 Often they come from high-achieving or overprotective families
 At first, self-esteem was raised – “you look
great”
Symptoms Of Inadequate
Energy Intake








Physical health
Mental health
Amenorrhea
Cold hands/feet
Constipation
Dry skin/hair loss
Headaches
Fainting/dizziness
Lethargy
Anorexia




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Concentration
Decisions
Irritability
Depression
Social withdrawal
Obsessiveness
(food)
Anorexia Nervosa

Complications
 Hypothermia may result
 Results when the body’s natural isolation fat
stores become non-existent and the victim
becomes cold all the time
 Some must be tube-fed to prevent death
 Some will die from heart failure
Anorexia Nervosa

Prognosis



With individual, group, and family therapy there is
a good chance for improvement and hopefully
recovery
Anti-depressants are often combined with these
therapies
It is a life-long process though
Anorexia Nervosa (pursuit of
thinness)



Successful Weight Loss – Hallmark of Anorexia
 Defined as 15% below expected weight
 Intense fear of obesity and losing control over eating
 Anorexics show a relentless pursuit of thinness, often
beginning with dieting
DSM-IV Subtypes of Anorexia
 Restricting subtype – Limit caloric intake via diet and
fasting
 Binge-eating-purging subtype – About 50% of anorexics
Associated Features
 Most show marked disturbance in body image
 Most are comorbid for other psychological disorders
 Methods of weight loss can have severe life threatening
medical consequences
Anorexia: Facts and Statistics
0.5-5% 15-19 year old females
 Majority are female (90-95%) and white
(> 95%), from middle-to-upper middle
class families
 Usually develops around age 13 or early
adolescence
 Tends to be more chronic and resistant to
treatment than bulimia
 3rd most common chronic illness in
adolescents

Major Systems Affected




Metabolic
 Hypometabolism/
Refeeding Syndrome
Cardiovascular
 Arrhythmias
Musculoskeletal
 Osteoporosis
Reproductive
 Amenorrhea
Bulimia Nervosa
(avoidance of obesity)

Associated Features




Most are within 10% of
target body weight
Most are over
concerned with body
shape, fear gaining
weight
Most are comorbid for
other psychological
disorders
Purging methods can
result in severe medical
problems
Bulimia Nervosa
Disorder characterized by repeated bingepurge episodes of overeating followed by
vomiting or using a laxative
 Again, mostly women in their early teens
 These individuals can be thin, average in
weight or even overweight – so this one is
more likely to go unnoticed by family or
friends

Bulimia Nervosa

Symptoms of Bulimia
 Eating
binges
 Purging
 Sore throat
 Mouth and throat ulcers
 Swollen salivary glands
 Destruction of tooth enamel
 Depression, obsessive-compulsive symptoms
Bulimia Nervosa

Prognosis



With the long-term psychotherapy combined with
group and family therapy the patient will likely
improve
Often, anti-depressants are combined with
therapy
Again, this is a life-long process
Bulimia: Facts and Statistics

Bulimia
 Majority are
female, with onset
around 16 to 19
years of age
 Lifetime
prevalence is
about 1.1% for
females, 0.1% for
males
 5-10% of college
women suffer from
bulimia
 Tends to be
chronic if left
untreated
Signs And Symptoms Of Vomiting
Or Laxative Abuse
Physical health


Weight loss
Electrolyte
disturbance





K
CO2
Dental enamel
erosion
Hypovolemia
Knuckle calluses
Mental health




Guilt
Depression
Anxiety
Confusion
At-Risk Groups for both AN and BN

Adolescent females
with low self-esteem

Gymnasts

Dancers (ballet)

Wrestlers

Runners

When thinness is
related to success
AN & BN:
Engaging Parents in Treatment

Developmental framework (child  adult)

Discuss blame, fault, guilt openly

Realignment of roles in family

Positive framing of family attributes

Future orientation

Authority to treat, and empowerment of,
professionals comes from parents
Problems Addressed In Mental
Health Treatment








Low Self-esteem
Distorted body-image
Dysfunctional coping
behaviors and habits
Depression
 SSRIs for BN and
weight recovered AN
Ineffective
communication
Conflict resolution
Lack of assertiveness
Post-trauma recovery
(sexual abuse, etc)
Indications for Hospitalization






Severe malnutrition: Weight for height
<75%
Dehydration
Electrolyte disturbances
Cardiac dysrhythmia
Physiologic instability
 Severe bradycardia or hypotension
 Hypothermia
 Orthostatic pulse changes
http://www.adolescenthealth.org/html/eating_disorders.h
tml
Indications for Hospitalization

Arrested growth and
development

Failure of outpatient
treatment

Acute food refusal

Uncontrollable bingeing
and purging

Acute medical
complication of
malnutrition

Acute psychiatric
emergencies

Comorbid diagnosis
interfering with treatment
(Fisher et al.,1995)
Eating Disorder,
Not Otherwise Specified






All criteria for AN, except still menstruating
All criteria for AN, except normal weight
All criteria for BN, except frequency or
duration
Compensatory weight control after small
amounts of food
Chewing/spitting out, but not swallowing,
large amounts of food
Binge eating disorder
Binge-Eating Disorder


Binge-Eating Disorder – Appendix of
DSM-IV
 Experimental diagnostic category
 Engage in food binges, but do not
engage in compensatory behaviors
Associated Features
 Many persons with binge-eating
disorder are obese
 Most are older than bulimics and
anorexics
 Show more psychopathology than
obese people who do not binge
 Share similar concerns as
anorexics and bulimics regarding
shape and weight
Signs And Symptoms Of Binge
Eating
Physical health





Weight gain
Bloating
Fullness
Lethargy
Salivary gland
enlargement
Mental health



Guilt
Depression
Anxiety
How do biological factors lead to
eating disorders?
Women who have close relative with an
eating disorder are 2-3 times more likely
to suffer from one
 More likely to occur in both identical twins
than fraternal twins (higher
concordance)
 Anorexa sufferers have higher levels of
serotonin
 Bulimia sufferers are less sensitive to
serotonin

What psychological factors lead
to eating disorders?

Cultural norms
 Thinness norm is
portrayed in
media
Brazilian model Ana Carolina Reston…this 21-year-old
anorexic model reportedly weighed just 88 pounds
What psychological factors lead
to eating disorders?

Family dynamics



Families of women with eating disorders are
particularly focused on weight and shape
Families of anorexics have potentially
dysfunctional dynamics
Families of bulimics have more conflict, and
less nurturance
What psychological factors lead
to eating disorders?

Personality



The “perfect child” expectation in families
Anorexics: rigid, anxious, perfectionists, and
obsessed with order and cleanliness
Bulimics: depressed, anxious, lack clear sense
of self-identity, have negative self-views
What approaches help prevent
eating disorders?

Interventions specifically targeting women
with poor body images can be effective
Weight Gain

Rate  1 lb/week, Target weight >85% average, if
low...

70% of weight gain is lean body mass (muscle)

Must eat adequately to gain lean body mass

 Lean body mass will result in
 Higher metabolism
 More energy


Fewer symptoms
Cognitive-behavioral therapy is used to design
programs for weight gain
“But, I’m Not Hungry”
Physiologic Fact







Body burns calories
throughout life

Appetite  need to eat

Eating Disorder 
Appetite 

If only respond to
appetite, will not get

enough energy
If eat on regular schedule,
more likely to get energy 
Higher energy fuel
ensures greater likelihood
of getting enough energy
Reframing for patient
Even if you’re not hungry,
your body burns calories
Appetite  car’s gas gauge
Eating Disorder  broken gas
gauge
If drive car with broken gas
gauge can run out of gas
Fill car with gas based on
miles driven & gas mileage
Fat has more energy than
carbohydrate or protein and
is a necessary body fuel
Lingering issues…

Is obesity really unhealthy?


“upper-body fat” is particularly bad
Can eating disorder prevention programs have
dangerous effects?



Eating disorder prevention programs can sometimes lead
to an increase in disordered behavior
Nova film, “Dying to be Thin” - emaciated women are
triggering girls who want to be thin.
Instead… Show the videos: “Body Talk”, or “Killing Us
Softly”. Shows being able to express their body image
and resist media messages.
Credits

Some slides in this presentation prepared with the asistance of
the following websites:
 http://www.healthypotato.com/downloads/Glycemic_Index_88-05.ppt
 http://www2.una.edu/psychology/health/ch08%20obesity2.pp
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