Gazzaniga • Heatherton • Halpern
Psychological Science
Chapter 10
Emotion and Motivation
©2013 W. W. Norton & Company, Inc.
“Violence Not What Attracts Video Gamers, Says Study”
Just a few days after a U.S. congressman proposed legislation
that would brand violent video games with a health warning, a
new study was released that showed that violence is not what
attracts players. The research could be reassuring news for
“Anti-Stress Video Game”
A simple video game has been shown to reduce stress. As this
ScienCentral News video explains, researchers at McGill
University found that playing the game also resulted in
increased productivity.
Emotion and Motivation
• When surgeons removed a noncancerous tumor from Elliot’s brain
they could not avoid removing some of the surrounding frontal lobe
• Elliot’s physical recovery was quick, and he continued to be a
reasonable, intelligent, and charming man with a superb memory
but no longer experienced emotion after the surgery
• The absence of emotions sabotaged Elliot’s ability to make rational
decisions, even about trivial things, and robbed him of his ability to
function as a member of society
Imagine living without feelings or aspirations to make something of
yourself. What sort of life would that be?
How profoundly do your feelings affect what you think and do?
10.1 How Do We
Experience Emotions?
• Distinguish between primary and secondary
• Compare and contrast the James-Lange, CannonBard, and Schachter-Singer two-factor theories of
• Discuss the roles that the amygdala and prefrontal
cortex play in emotional experience.
• Define misattribution of arousal and excitation
• Discuss common strategies that people use to
regulate their emotional states.
“Gambling Brain”
Whether you’re buying a one-dollar Mega Millions lottery
ticket, joining a ten-dollar March Madness office pool, or
making a large investment in the stock market, your brain has
to predict risk. Now researchers say they can predict how
much you would be willing to risk based on your brain
patterns. This ScienCentral News video has more.
10.1 How Do We
Experience Emotions?
• The terms emotion and mood are often used interchangeably
in everyday language, but it is useful to distinguish between
– emotion (affect): feelings that involve subjective evaluation,
physiological processes, and cognitive beliefs. Emotions typically
interrupt whatever is happening, or trigger changes in thought and
• subjective experience: feelings that accompany an emotion
• physical changes: increases in heart rate, in skin temperature, and in brain
• cognitive appraisals: people’s beliefs and understandings about why they
feel the way they do
– mood: diffuse, long-lasting emotional states. Rather than interrupting
what is happening, they influence thought and behavior.
Emotions Have a
Subjective Component
• We experience emotions subjectively; we know we are
experiencing emotions because we feel them
• The intensity of emotional reactions varies but people who
are overemotional or underemotional tend to have
psychological problems, for example:
– mood disorders: such as depression or panic attacks;
– alexithymia: This disorder causes people to not experience the
subjective components of emotions, e.g. Elliot
• One cause of alexithymia is that the physiological messages
associated with emotions do not reach the brain centers that
interpret emotion
• Damage to certain brain regions, especially the prefrontal
cortex, is associated with a loss of emotion’s subjective
Distinguishing Between
Types of Emotions
• Distinguishing between primary and secondary emotions is
conceptually similar to viewing color as consisting of primary
and secondary hues:
– primary emotions: emotions that are evolutionarily adaptive, shared
across cultures, and associated with specific physical states. They
include anger, fear, sadness, disgust, happiness, and possibly surprise
and contempt.
– secondary emotions: blends of primary emotions. They include
remorse, guilt, submission, and anticipation
• At the center of the circumplex model is the intersection of
two core dimensions of affect:
– Valence indicates how negative or positive emotions are; activation
indicates how arousing they are
• arousal: physiological activation (such as increased brain activity) or
increased autonomic responses (such as increased heart rate, sweating, or
muscle tension)
Negative Affect and Positive Affect
• Neurochemical evidence supports the idea that positive affect
and negative affect are independent
• Positive activation states appear to be associated with an
increase in dopamine
• Negative activation states appear to be associated with an
increase in norepinephrine
• Crying results mainly when negative events leave us unable to
respond behaviorally to the emotions we are feeling
• Crying may relieve stress through activation of the
parasympathetic nervous system and serve an important
social function by bringing sympathy and social support from
Emotions Have a Physiological
Component : James-Lange Theory
• In 1884, William James asserted that a person’s
interpretation of the physical changes in a situation
leads that person to feel an emotion
• A similar theory was independently proposed by the
physician and psychologist Carl Lange
• According to what is called the James-Lange theory
of emotion, we perceive specific patterns of bodily
responses, and as a result of that perception we feel
Facial Feedback Hypothesis
• One implication of the counterintuitive James-Lange
theory is that if you mold your facial muscles to
mimic an emotional state, you activate the
associated emotion
– Facial expressions trigger the experience of emotions, not
the other way around
• In 1963, Silvan Tomkins proposed this idea as the
facial feedback hypothesis
• In other words, putting on a smile can trigger a
happy response
Cannon-Bard Theory
• Walter B. Cannon, along with Philip Bard, proposed
that the mind and body experience emotions
• The mind is quick to experience emotions; the body
is much slower, taking at least a second or two to
• According to the Cannon-Bard theory of emotion, the
information from an emotion-producing stimulus is
processed in subcorticalstructures
• As a result, we experience two separate things at
roughly the same time: an emotion and a physical
The Amygdala
• The amygdala processes the emotional significance of stimuli,
and generates immediate emotional and behavioral reactions
• This is the brain structure most important for emotional
learning, as in the development of classically conditioned fear
• People with damage to the amygdala show fear when
confronted with dangerous objects, but they do not develop
conditioned fear responses to objects associated with
dangerous objects
• The amygdala is associated with emotional learning, memory
of emotional events, and the interpretation of facial
expressions of emotion
The Prefrontal Cortex
• The right and left prefrontal cortices are
associated with negative and positive affect,
respectively; This pattern is known as cerebral
• People also can be dominant in one
hemisphere of their frontal lobes, and that
dominant hemisphere can bias their emotions
Emotions Have a Cognitive Component:
Schachter-Singer Two-Factor Theory
• According to the two-factor theory of
emotion, a situation evokes a physiological
response, such as arousal, and a cognitive
interpretation, or emotion label
• When people experience arousal they initiate
a search for its source
• According to the two-factor theory, whatever
the person believes caused the emotion will
determine how the person labels the emotion
We Can Misattribute the Sources
of Our Emotional States
• One interesting implication of the two-factor theory
is that physical states caused by a situation can be
attributed to the wrong emotion
• When people misidentify the source of their arousal,
it is called misattribution of arousal
• Excitation transfer is a similar form of misattribution;
residual physiological arousal caused by one event is
transferred to a new stimulus
We Regulate Our Emotional States
• In our daily lives, circumstances often require us to harness
our emotional responses
– How do you mask your expression of disgust when you are
obligated by politeness to eat something you dislike?
• Gross outlined the ways we strategically place ourselves in
certain situations in order to self-regulate
– Can you think of any specific examples?
• Recent studies have found that engaging in reappraisal
changes the activity of brain regions involved in the
experience of emotion
• Not all strategies for regulating emotional states are equally
“Moral Dilemma”
Brain scans are often used to spot physical ills. But one researcher
is using MRI images to map how your brain makes sense of moral
problems as well. This ScienCentral News video explains.
• Humor increases positive affect and can be used to
cope with a difficult situation
• Research shows that laughter stimulates endocrine
secretion, improves the immune system, and
stimulates the release of hormones, dopamine,
serotonin, and endorphins
• According to one theory, people sometimes laugh in
situations that do not seem very funny (e.g. funerals)
to distance themselves from their negative emotions,
and strengthen their connections to other people
“Humor and the Sexes”
Scientists have confirmed something many of us may have
already suspected, that the brains of men and women react
differently when we find something funny. As this
ScienCentral News video explains, the study could help
scientists understand how humor helps us cope with stress.
Thought Suppression and Rumination
• Through thought suppression, people attempt to not
feel or respond to the emotion at all
• Thought suppression often leads to a rebound effect,
in which people think more about something after
suppression than before
• Rumination involves thinking about, elaborating, and
focusing on undesired thoughts or feelings
• Rumination prolongs the mood, and it impedes
successful mood regulation strategies, such as
distracting oneself or focusing on solutions for the
• Distraction involves doing something other than the
troubling activity or thinking about something other
than the troubling thought
• By absorbing attention, distraction temporarily helps
people stop focusing on their problems
• Distractions can backfire if people change their
thoughts but end up thinking about other problems
or engaging in maladaptive behaviors, e.g. overeating
or binge drinking
10.2 How Are Emotions Adaptive?
• Review research on the cross-cultural
universality of emotional expressions.
• Define display rules.
• Discuss the impact of emotions on decision
making and self-regulation.
• Discuss the interpersonal functions of guilt
and embarrassment.
10.2 How Are Emotions Adaptive?
• Emotions are adaptive because they prepare and
guide successful behaviors.
• Negative and positive experiences have guided our
species to behaviors that increase the probability of
our surviving and reproducing.
• Emotions provide information about the importance
of stimuli to personal goals, and then they prepare
people for actions aimed at achieving those goals.
– goal:a desired outcome, usually associated with some
specific object (tasty food) or some future behavioral
intention (getting into a doctoral program in psychology)
Facial Expressions
Communicate Emotion
• Charles Darwin argued that expressive aspects of emotion are
adaptive because they communicate how we are feeling
• Facial expressions provide many clues about whether our
behavior is pleasing to others or whether it is likely to make
them reject, attack, or cheat us
• Facial expressions, like emotions themselves, provide adaptive
• Dunlap demonstrated that the mouth better conveys emotion
than the eyes, especially for positive affect
• Researchers showed identical facial expressions in different
contexts and found that the context profoundly altered how
people interpreted the emotion
Facial Expressions Across Cultures
• Research has found general support for cross-cultural
congruence in identifying some facial expressions;
support is strongest for happiness and weakest for
fear and disgust
• Evidence indicates that some facial expressions are
universal and probably have a biological basis
• Research suggests that pride responses are innate
rather than learned by observing them in others
• In studies of athletes, both sighted and blind winners
display similar expressions
Display Rules Differ across Cultures
and between the Sexes
• Display rules govern how and when people exhibit emotions
– display rules: rules learned through socialization that dictate which emotions
are suitable to given situations
• Differences in display rules help explain cultural stereotypes
• From culture to culture, display rules tend to be different for women and
• The emotions most closely associated with women are related to
caregiving, nurturance, and interpersonal relationships
• The emotions associated with men are related to dominance,
defensiveness, and competitiveness
Do sex differences in emotional expression reflect learned patterns of
behaviors or biologically based differences?
Nature and nurture work together here, so it is difficult — often
impossible — to distinguish their effects
Emotions Serve Cognitive Functions
• Our immediate affective responses arise quickly and
automatically and color our perceptions at the very
instant we notice an object
• These instantaneous evaluations subsequently guide
decision making, memory, and behavior
• Our decisions and judgments are affected by our
• When people are pursuing goals, positive feelings
signal that they are making satisfactory progress and
thereby encourage additional effort
“Brain Blindness”
We all know that seeing something emotional can distract us,
but researchers say that it might even blind us—not in our
eyes, but in our brains. This ScienCentral news video explains.
Decision Making
• Emotions influence our decision making in different ways
• We anticipate our future emotional states, which then serve as a source of
information and a guide in decision making.
• In the face of complex, multifaceted situations, emotions serve as
heuristic guides: They provide feedback for making quick decisions
• Risk judgments are strongly influenced by current feelings, and when
emotions and cognitions are in conflict, emotions typically have the
stronger impact on decisions
• According to the affect-as-information theory, posited by Schwarz and
Clore, we use our current moods to make judgments and appraisals, even
if we do not know the sources of our moods
• If people are made aware of the sources of their moods (as when the
researcher suggests that a good mood might be caused by the bright
sunshine), their feelings have less influence over their judgments
“Mood and Money”
Feeling sad and bad about ourselves is not only unpleasant, it
can also be hard on our wallets. Psychology researchers have
found that when you shop while feeling these emotions, you
may pay three times more for the same item than when you’re
in a better mood, as this ScienCentral News video reports.
Critical Thinking Skill:
Recognizing and Correcting for Belief Persistence
in Your Own Thinking and in That of Others
• Belief persistence (my side bias):tendency to hold on to
previous ideas even when presented with evidence that the
belief is questionable or just plain wrong
• People tend to believe information consistent with the side of
an issue they already believe is true
• You can be more open to examining all sides of an issue fairly
and altering your beliefs when the evidence supports the
• To reduce the effects of belief persistence, you should
deliberately seek evidence that disconfirms your belief
Somatic Markers
• According to Domasio’s somatic marker theory, most selfregulatory actions and decisions are affected by bodily
reactions called somatic markers
– somatic markers: bodily reactions that arise from the emotional
evaluation of an action’s consequences
• Expectation is influenced by your history of performing either
that action or similar actions
• Somatic markers may guide us to engage in adaptive
behaviors by using past outcomes to regulate future behavior
• Damasio has found that patients, such as Elliot, who have
damage to the middle of the prefrontal region, often are
insensitive to somatic markers
• When this region is damaged, people still can recall
information, but it has lost most of its affective meaning
“Lying Faces”
When the stakes are high, emotion in the face and voice may
give away hard-to-spot liars. As this ScienCentral News video
reports, one researcher studying deception for the military is
finding information that may be helpful in love and war.
Emotions Strengthen
Interpersonal Relations
• In interacting with others, we use emotional expressions as
powerful nonverbal communications
• Nonverbal displays of emotions signal inner states, moods,
and needs
• Theorists have reconsidered interpersonal emotions in view of
humans’ evolutionary need to belong to social groups
• Survival was enhanced for those who lived in groups; those
who were expelled would have been less likely to survive and
pass along their genes
• The fundamental need to belong indicates that people will be
sensitive to anything that might lead them to be kicked out of
the group, and social emotions may reflect reactions to this
Guilt Strengthens Social Bonds
Guilt is a negative emotional state associated with anxiety, tension, and agitation
The typical guilt experience occurs when someone feels responsible for another
person’s negative affective state
Roy Baumeister and colleagues contend that guilt protects and strengthens
interpersonal relationships in three ways:
– Feelings of guilt discourage people from doing things that would harm their
– Displays of guilt demonstrate that people care about their relationship partners, thereby
affirming social bonds;
– Guilt is a tactic that can be used to manipulate others
Evidence indicates that socialization is more important than biology in determining
specifically how children experience guilt
Parental warmth is associated with greater guilt in children suggesting that feelings
of guilt arise in healthy and happy relationships.
As children become citizens in a social world, they develop the capacity to
empathize, and they subsequently experience feelings of guilt when they
transgress against others
Embarrassment and Blushing
• A person is likely to feel embarrassed after violating a
cultural norm, losing physical poise, being teased, or
experiencing a threat to his or her self-image
• Like guilt, embarrassment may reaffirm close
relationships after wrongdoing
• Recent theory and research suggests that blushing
occurs when people believe others view them
negatively and that blushing communicates a
realization of interpersonal errors
• This nonverbal apology is an appeasement that
elicits forgiveness in others, thereby repairing and
maintaining relationships
10.3 How Does Motivation
Energize, Direct, and Sustain Behavior?
Distinguish between a motive, a need, and a drive.
Describe Maslow’s hierarchy of needs.
Describe the Yerkes-Dodson law.
Distinguish between extrinsic motivation and
intrinsic motivation.
• Discuss the relationships between self-efficacy, the
achievement motive, delayed gratification, and goal
• Describe needto belong theory.
10.3 How Does Motivation
Energize, Direct, and Sustain Behavior?
• Emotions are a primary source of motivation.
– motivation: factors that energize, direct, or sustain behavior
• Most of the general theories of motivation emphasize four
essential qualities of motivational states. Motivational states:
– are energizing or stimulating; they activate behaviors;
– are directive; they guide behaviors toward satisfying specific goals or
specific needs;
– help animals persist in their behavior until they achieve their goals or
satisfy their needs;
– differ in strength, depending on internal and external forces.
Multiple Factors Motivate Behavior
Needs lead to goal-directed behaviors; failure to satisfy a particular need leads to
psychosocial or physical impairment
– need: a state of biological or social deficiency
Maslow believed that people are driven by many needs, which he arranged into a
need hierarchy
– need hierarchy: Maslow’s arrangement of needs, in which basic survival needs must be
met before people can satisfy higher needs
Maslow’s “need theory” is an example of humanistic psychology because itfocuses
on the person in motivation, e.g. it is the person who desires food, not the
person’s stomach
A state of self-actualization occurs when someone achieves his or her personal
dreams and aspirations
Maslow’s hierarchy is more useful as an indicator of what might be true about
people’s behaviors than of what actually is true about them
– For example, some people starve themselves in hunger strikes to demonstrate the
importance of their personal beliefs
– Others, who have satisfied their physiological and security needs, prefer to be left alone
Drives and Incentives
What motivates us to satisfy our needs?
– drive: a psychological state that, by creating arousal, motivates an organism to satisfy a
For biological states such as thirst or hunger, basic drives help animals maintain
steadiness, or equilibrium
– homeostasis: the tendency for bodily functions to maintain equilibrium. The term
homeostasis was coined by Walter Cannon
Hull proposed that when an animal is deprived of some need (such as water, sleep,
or sex) a drive increases in proportion to the amount of deprivation
Any behavior that satisfies a need is reinforced and therefore is more likely to
recur; if a behavior consistently reduces a drive, it becomes a habit
Drive states push us to reduce arousal, but we are also pulled toward certain
things in our environments
– incentives: external objects or external goals, rather than internal drives, that motivate
Even forces outside our conscious awareness can provide incentives for us to
behave in particular ways, e.g. subliminal messages or advertising
Arousal and Performance
• Yerkes-Dodson law: the psychological principle that
performance increases with arousal up to an optimal point, after
which it decreases with increasing arousal
– For example, As the Yerkes-Dodson law predicts, students perform
best on exams when feeling moderate anxiety. Too little anxiety can
make them inattentive or unmotivated, while too much anxiety can
interfere with their thinking ability.
• Motivation does not always lower tension and arousal; we are
individually motivated to seek an optimal level of arousal
• Sigmund Freud proposed that drives are satisfied according to
the pleasure principle, which drives people to seek pleasure
and avoid pain
• The concept of hedonism refers to humans’ desire for
• From an evolutionary perspective, positive and negative
motivations are adaptive
– For instance, the motivations to seek out food, sex, and
companionship are typically associated with pleasure, whereas the
avoidance of dangerous animals is negatively motivated because of
the association with pain
• Animals prefer to eat sweets; sweetness usually indicates that
food is safe to eat. By contrast, most poisons and toxins taste
bitter, so it is not surprising that animals avoid bitter tastes
“Food Addiction”
Obesity researchers have found that the mere presence of
food triggers brain regions associated with motivation and
pleasure. This ScienCentral report has the skinny on what
might be making us fat.
Some Behaviors Are Motivated
for Their Own Sake
• Pleasure can be associated with the satisfaction of biological needs and
the performance of adaptive behaviors
– extrinsic motivation: motivation to perform an activity because of the
external goals toward which that activity is directed, e.g. working to receive a
– intrinsic motivation: motivation to perform an activity because of the value or
pleasure associated with that activity, rather than for an apparent external
goal or purpose, e.g. reading a good novel, listening to music
• Playful exploration is characteristic of all mammals — especially primates
• Play helps us learn about the objects in an environment and has survival
value, since knowing how things work allows us to use those objects for
more serious tasks
• Creativity is the tendency to generate ideas or alternatives that may be
useful in solving problems, communicating, and entertaining ourselves
and others
• Creativity is an important factor in solving adaptive problems
“Teens Reading”
Every year, more than a million teens drop out of high
school, mostly because they can’t read well. Right now,
researchers aren’t sure how to help teens get out of reading
trouble. But one things they do know is: they have to figure
out how to persuade teenagers to read in the first place.
This ScienCentral News video has more.
Self-Determination Theory
and Self-Perception Theory
• Consistent evidence suggests that extrinsic rewards can
undermine intrinsic motivation
– self-determination theory:People are motivated to satisfy needs for
competence, relatedness to others, and autonomy, which is a sense of
personal control. Extrinsic rewards may reduce intrinsic value because
such rewards undermine people’s feeling that they are choosing to do
something for themselves. In contrast, feelings of autonomy and
competence make people feel good about themselves and inspire
them to do their most creative work (Deci& Ryan, 1987).
– self-perception theory: People are seldom aware of their specific
motives; they draw inferences about their motives according to what
seems to make the most sense (Bem, 1967).
• Rewarding people for engaging in an intrinsic activity gives
them an alternative explanation for engaging in it; the reward
replaces the goal of pure pleasure
We Set Goals to Achieve
• Henry Murray proposed 27 basic psychosocial needs, including the needs
for power, autonomy, achievement, and play
• A key insight in the study of psychosocial needs is that people are
especially motivated to achieve personal goals
• Self-regulation of behavior is the process by which people change their
behavior to attain personal goals
• According to an influential theory developed by Locke and Latham,
challenging — but not overly difficult — and specific goals are best
• Challenging goals encourage effort, persistence, and concentration; goals
that are too easy or too hard can undermine motivation and therefore
lead to failure
• Dividing specific goals into concrete steps and focusing on short-term
goals facilitates achieving long-term goals
Critical Thinking Skill:
Recognizing When Psychological Reactance
May Be Influencing Your Thinking
• Psychological reactance is a motivational state
aroused when our feelings of personal freedom are
threatened and often affects how we make choices
• The common notion of reverse psychology is based
on psychological reactance, e.g. playing hard to get
• By noticing if your thinking has been influenced by
this potentially irrelevant variable, you will find it
easier to make better-informed and more-rational
Self Efficacy and the
Achievement Motive
• Bandura argued that people’s personal expectations
for success play an important role in motivation
• Self efficacy is the expectancy that your efforts will
lead to success. This expectancy helps mobilize your
energies, e.g. not believing your efforts will pay off
may discourage you from trying
• The achievement motive is the desire to do well
relative to standards of excellence
• Individuals high in achievement need set challenging
but attainable personal goals, while those low in
achievement need set extremely easy or impossibly
high goals
Delayed Gratification
One common challenge in self-regulation is postponing immediate gratification in
the pursuit of long-term goals
The ability to delay gratification is predictive of success in life
According to Mischel and Metcalf, the most successful strategy to delay
gratification involves turning hot cognitions into cold cognitions — mentally
transforming the desired object into something undesired
– Hot cognitions focus on the rewarding, pleasurable aspects of objects
– Cold cognitions focus on conceptual or symbolic meanings
Metcalfe and Mischel proposed that this hot/cold distinction is based on how the
brain processes the information
The amygdala and the nucleus accumbens are important for motivating behavior
The prefrontal cortex performs cold-cognitive processes, such as the control of
thought and of behavior and helps us make choices that may optimize survival
We Have a Need to Belong
• Over the course of human evolution, our ancestors
who lived with others were more likely to survive
and pass along their genes
• Effective groups shared food, provided mates, and
helped care for offspring, including orphans
• Roy Baumeister and Mark Leary formulated the need
to belong theory, which states that the need for
interpersonal attachments is a fundamental motive
that has evolved for adaptive purposes
Making and Keeping Friends
• Societies differ in their types of groups, but all
societies have some form of group membership
• Not belonging to a group increases a person’s risk for
various adverse consequences, such as illnesses and
premature death, and suggests that the need to
belong is a basic motive driving behavior
• Evidence indicates that people feel anxious when
facing exclusion from their social groups
• People who are shy and lonely tend to worry most
about social evaluation and pay much more attention
to social information
Anxiety and Affiliation
• Schachter found that increased anxiety led to increased
• According to Schachter, other people provide information that
helps us evaluate whether we are acting appropriately
• According to Festinger’ssocial comparison theory,we are
motivated to have accurate information about ourselves and
others; we compare ourselves with those around us to test
and validate personal beliefs and emotional responses
• The effect occurs especially when the situation is ambiguous
and we can compare ourselves with people relatively similar
to us
Psychology: Knowledge You Can Use—
How Might Psychology Influence
My Working Life?
• Industrial and Organizational (I-O) psychology applies findings
from psychological science to work settings
• Key challenges in I-O psychology include helping employers
deal with employees fairly, helping employers design jobs so
that workers find them interesting and satisfying, and helping
workers be more productive
• An important finding in I-O psychology is that satisfied
workers are the best workers; people will work hardest when
their jobs are meaningful and when they feel they have some
control over what they do
• Assess your strengths and weaknesses and try to develop a
general idea of the kind of career you can pursue effectively
and are likely to find fulfilling
10.4 What Motivates Eating?
• Discuss the impact of time, taste, and cultural
learning on eating behavior.
• Identify neural structures associated with
• Describe the glucostatic and lipostatic theories
of eating.
• Discuss the role that hormones play in
regulating eating behavior.
10.4 What Motivates Eating?
• Eating involves much more than survival.
• Around the globe, special occasions often involve
elaborate feasts, and much of the social world
revolves around eating.
• Common sense dictates that most eating is
controlled by hunger and satiety, but the amount an
individual consumes can vary from person to person.
What complex interactions between biology, cultural
influences, and cognition determine our eating
Time and Taste Set the Stage
We have been classically conditioned to associate eating with regular mealtimes
The clock indicating mealtime is much like Pavlov’s metronome: It leads to various
anticipatory responses that motivate eating behavior and prepare the body for
digestion, e.g. an increase in insulin promotes glucose use and increases shortterm hunger signals
Flavor and variety motivate eating. Animals, including humans, will stop eating
relatively quickly if they have just one type of food to eat, but they will continue
eating if presented with a different type of food
– sensory-specific satiety: Animals eat more when presented with a variety of foods in
that they quickly grow tired of any one flavor
The region of the frontal lobes that is involved in assessing the reward value of
food exhibits decreased activity when the same food is eaten over and over but
increased activity when a new food is presented
Sensory-specific satiety may be advantageous because animals that eat many
types of food are more likely to satisfy nutritional requirements.
Eating large meals may have been adaptive when the food supply was scarce or
Culture Plays a Role
• What people will eat is determined by a combination of personal
experience and cultural beliefs, and has little to do with logic and
everything to do with what we believe is food
• Unfamiliar foods may be dangerous or poisonous, so avoiding them is
adaptive for survival
• Local norms for what to eat and how to prepare it—guidelines that Rozin
calls cuisine — reinforce many food preferences
• Religious and cultural values often tell people which foods to avoid
• Taboos on certain types of food may have been adaptive in the past
because those foods were likely to contain harmful bacteria
• Many food taboos and preferences are idiosyncratic and reflect an evolved
group preference for specific foods, prepared and eaten in certain ways
• Culturally transmitted food preferences powerfully affect our diet
Brain Structure, Homeostasis,
and Hormones Direct the Action:
Neural Processes
The hypothalamus integrates the various inhibitory and excitatory feeding
messages, and it organizes behaviors involved in eating
Damage to the hypothalamus dramatically changes eating behavior and body
– Ventromedial/middle region (VMH): eat far more than normal; hyperphagialeads to
– Lateral/outer region (LH): eat far less than normal; aphagialeads to weight loss and
eventual death unless force fed
The hypothalamus monitors various hormones and nutrients and operates to
maintain a state of homeostasis
A region of the prefrontal cortex processes taste cues such as sweetness and
saltiness and indicates the potential reward value of particular foods
The craving triggered by seeing tasty food is associated with activity in the limbic
Damage to the limbic system or the right frontal lobes sometimes produces
gourmand syndrome, in which people become obsessed with the quality and
variety of food and how food is prepared
“Taste the Difference”
Is it possible that overweight people get more pleasure from
eating? As this ScienCentral News video reports, studies
indicate this may be why some people overeat.
Internal Sensations
• Contractions and distensions of the stomach can make the
stomach growl; however, research has established that these
movements are relatively minor determinants of hunger and
– People who have had their stomachs removed continue to report
being hungry
• The glucostatic theory proposes that the bloodstream is
monitored for its glucose levels
– Because glucose is the primary fuel for metabolism and is especially
crucial for neuronal activity, it makes sense for animals to become
hungry when they are deficient in glucose
• The lipostatic theory proposes a set-point for body fat
– When an animal loses body fat, hunger signals motivate eating and a
return to the set-point
Hormonal Activity
• Leptin is associated with long-term body fat
regulation, whereas ghrelin motivates eating
– leptin: released from fat cells as more fat is stored
and travels to the hypothalamus, where it acts to
inhibit eating behavior
– ghrelin: originates in the stomach; surges before
meals, then decreases after people eat — may
play an important role in triggering eating
10.5 What Motivates
Sexual Behavior?
• Review the four stages of the sexual response cycle.
• Discuss the role that hormones play in sexual
• Identify the primary neurotransmitters involved in
sexual behavior.
• Discuss sex differences in sexual behavior and in
mate preferences.
• Review contemporary theories of sexual orientation.
10.5 What Motivates
Sexual Behavior?
• Variation in sexual frequency can be explained
by individual differences and by society’s
dominating influence over how and when
individuals engage in sexual activity.
• Pioneering research by Alfred Kinsey launched
the study of human sexual behavior and
shattered many myths regarding men’s and
women’s sexual lives.
Biology Influences Sexual Behavior
• Masters and Johnson gained considerable insight
into the physiology of human sexual behavior
– sexual response cycle: a four-stage pattern of physiological
and psychological responses during sexual activity
• excitement phase: occurs when people contemplate sexual activity
or begin engaging in sexual behaviors
• plateau phase: pulse rate, breathing, and blood pressure increase,
as do the various other signs of arousal
• orgasm phase: involuntary muscle contractions throughout the
body, dramatic increases in breathing and heart rate, rhythmic
contractions of the vagina for women, and ejaculation of semen
for men
• resolution phase: dramatic release of sexual tension and a slow
return to a normal state of arousal
Hormones are involved in producing and terminating sexual behaviors
Hormones influence the development of secondary sex characteristics during
puberty and motivate sexual behavior
Males have a greater quantity of androgens than females do, and females
have a greater quantity of estrogens and progesterone
Males need a certain amount of testosterone (a type of androgen) to be able
to engage in sex, but they do not perform better if they have more
The more testosterone women have, the more likely they are to have sexual
thoughts and desires — although normal females have relatively low levels of
Oxytocin is released during sexual arousal and orgasm
Some researchers believe oxytocin may promote feelings of love and
attachment between partners; it also seems to be involved in social behavior
more generally
The hypothalamus is the brain region considered most important for
stimulating sexual behavior
“Addicted to Love”
Ever wondered what fuels that flame when you fall in love? As
this ScienCentral News video reports, brain scientists have
found that it’s all in your head.
• Neurotransmitters, including dopamine, serotonin, and nitric
oxide, have also been found to influence sexual functioning
• Dopamine receptors in the limbic system are involved in the
physical experience of pleasure, and dopamine receptors in
the hypothalamus stimulate sexual activity
• The most common pharmacological treatments for
depression enhance serotonin function, but they seriously
reduce sexual interest, especially for women
• Sexual stimulation leads to nitric oxide production. The
increased nitric oxide promotes blood flow to both the penis
and the clitoris and subsequently plays an important role in
sexual arousal, especially penile erections.
Variations Across the Menstrual Cycle
• Women differ from men in how the hypothalamus
controls the release of sex hormones
• In men, hormones are released at the same rate over
• In women, the release of hormones varies according
to a cycle that repeats itself approximately every 28
days: the menstrual cycle
• Research has found only minimal evidence that
women’s sexual behavior varies across the menstrual
cycle; however, women may process social
information differently depending on whether they
are in a fertile phase of the cycle
“PMS’s Flip Side”
PMS may have a flip side. Brain researchers have found that an
important brain circuit changes its activity along with women’s
fluctuating hormone levels. As this ScienCentral News video
explains, it’s the brain circuit that seeks and experiences
Visual Erotic Stimulation
• Some brain imaging studies indicate that viewing erotica
activates reward regions in the brain, such as various
limbic structures
• Hamann and colleagues found that when men and
women viewed sexually arousing stimuli, such as film
clips of sexual activity or pictures of opposite-sex nudes,
men showed more activation of the amygdala
• Research has shown that women prefer erotica produced
specifically for women, which tends to emphasize more
of the emotional factors of sexual interaction
Culture Scripts and Cultural Rules
Shape Sexual Interactions
• The depiction of sexual behavior in movies
and other media shapes beliefs and
expectations about what sexual behaviors are
appropriate and when they are appropriate
• Sexual scripts are cognitive beliefs about how
a sexual episode should be enacted
• The scripts differ in many places in the world,
such as in countries where arranged marriages
are common
Regulating Sexual Behavior
• Most of the changes in sexual behaviors must be attributed to
changes in cultural pressures and cultural expectations
• Although sexual customs and norms vary across cultures, all
known cultures have some form of sexual morality
– For example, one well-known pattern of regulating sexual behavior is
the double standard. This unwritten law stipulates that certain
activities (such as premarital or casual sex) are morally and socially
acceptable for men but not for women.
• Cultures may seek to restrain and control sex for various
reasons, including maintaining control over the birthrate,
helping establish paternity, and reducing conflicts
Sex Differences in Sexual Behavior
• A study of more than 16,000 people from 10 major regions around the
world found that the greater male motivation for sexual activity and
sexual variety occurs in all cultures
• Baumeister’s term erotic plasticity refers to the extent that sex drive can
be shaped by social, cultural, and situational factors
• Women’s sexual desires and behaviors depend significantly on social
factors such as education and religion, whereas men’s sexuality shows
minimal relationships to such influences
• To account for these differences, the evolutionary psychologist David Buss
has proposed the sexual strategies theory
– Sexual strategies theory: a theory that maintains that women and men have
evolved distinct mating strategies because they faced different adaptive
problems over the course of human history. The strategies used by each sex
maximize the probability of passing along their genes to future generations.
• According to the sexual strategies theory, women are more likely to be
more cautious about having sex because having offspring is a much more
intensive commitment for them than it is for men
Mate Preferences
• Men and women look for similar qualities in potential partners, but
men are more concerned about a potential partner’s attractiveness,
and women are more concerned with a potential partner’s status
• These differences in relative importance may be due to the different
adaptive problems the sexes faced over the course of human
evolutionary history
• Both men and women value physical attractiveness highly, but their
relative emphases conform to evolutionary predictions
• Instinctive behaviors are constrained by social context: The frontal
lobes work to inhibit people from breaking social rules, which are
determined largely by culture
• These standards shape the context in which men and women view
sexual behavior as desirable and appropriate
“The Stud Effect”
Is a woman’s choice to mate really a choice? As this
ScienCentral news video explains, researchers studying mice
have found that alpha males can trigger in females the growth
in new brain cells that make them want only alpha males.
We Differ in Our Sexual Orientations
• Homosexual behavior has been noted in various
forms throughout recorded history
• Until 1973, psychiatrists in Western cultures officially
viewed homosexuality as a mental illness
• Many theories of sexual orientation have emerged,
but none has received conclusive support
• The overwhelming majority of studies have found
little or no evidence that how parents treat their
children or environmental factors have anything to
do with sexual orientation
Biological Factors
• The best available evidence suggests that exposure
to hormones, especially androgens, in the prenatal
environment might play some role in sexual
• Researchers found that altering the expression of a
single “master” gene reversed the sexual
orientations of male and female flies
• It remains unclear how human sexual orientation
might be encoded in the genes
• Some research suggests the hypothalamus may be
related to sexual orientation
Biology and Environmental Factors
• Many psychologists believe it is likely that multiple
biological and environmental processes affect a
person’s sexual orientation in subtle ways
• Daryl Bem has proposed that feeling different from
opposite-sex peers or same-sex peers predicts later
sexual orientation
• Bem’s model is based on the idea of initial biological
differences in temperament but then proposes that
the social environment shapes what is sexually
• Bem’s theory is supported by anecdotal evidence,
but no concrete evidence supports it
Stability of Sexual Orientation
• No good evidence exists that sexual orientation can
be changed through therapy
• In some cultures and subcultures, people may
engage in same-sex behaviors for a period and then
revert to heterosexual behaviors
• Few psychologists or physicians believe sexual
orientation — as opposed simply to sexual activity —
is a choice or that it can be changed
• Homosexuals have always existed, whether or not
they were free to be themselves