Motivation and Emotion
Motivation: process that influences the direction, persistence, and vigour of goal-directed
Perspectives on Motivation
Instinct Theory and Evolutionary Psychology
Instinct: an inherited predisposition to behave in a specific and predictable way when exposed to
a particular stimulus.
• Instincts have a genetic basis
Homeostasis and Drive Theory
Homeostasis: a state of internal physiological equilibrium that the body strives to maintain.
1. Response system (restores equilibrium)
2. Control centre (receives information from the sensors and activates the response system)
Drive theory: physiological disruptions to homeostasis produce drives, states of internal tension
that motivate an organism to behave in ways that reduce this tension.
Incentive and Expectancy Theories
Incentives: environmental stimuli that “pull” an organism toward a goal (e.g. a good grade
would be an incentive to a student).
Expectancy x value theory: proposes that goal-directed behaviour is jointly determined by two
factors: the strength of the person’s expectation that particular behaviours will lead to a goal, and
the value the individual places on that goal-often called incentive value (Motivation=expectancy
x incentive value).
Extrinsic motivation: performing an activity to obtain an external reward or avoid punishment.
Intrinsic motivation: performing an activity for its own sake-because you find it enjoyable or
Overjustification hypothesis: giving people extrinsic rewards to perform activities that they
intrinsically enjoy may “overjustify” that behaviour and reduce intrinsic motivation.
Psychodynamic and Humanistic Theories
• Behaviour results from a never-ending battle between unconscious impulses struggling
for release and psychological defences used to keep them under control.
• Conscious mental processes, unconscious motives and tensions guide how we act and
feel. Deficiency needs: concerned with physical and social survival.
Growth needs: uniquely human and motivate us to develop our potential.
Need of hierarchy (concept): a progression of needs containing deficiency needs at the bottom
and growth needs at the top.
Self-actualization: the need to fulfill our potential and it is the ultimate human motive (“be all
that you can be”).
Self-determination theory: focuses on three fundamental psychological needs: competence,
autonomy, and relatedness.
Competence motivation: reflects a human need to master new challenges and perfect skills.
This need motivates much exploratory and growth-inducing human behaviour.
Autonomy and Relatedness:
• Autonomy: is satisfied when people experience their actions as a result of free choice
without outside interference.
• Relatedness: refers to our desire to form meaningful bonds with others.
o The two complement each other.
o When true relatedness is achieved, people often feel freer to be themselves.
o Adolescents who feel that their autonomy is acknowledged and supported by their
parents feel strong sense of relatedness to their parents.
Hunger and Weight Regulation
The Psychology of Hunger
Metabolism: the body’s rate of energy utilization, and about two-thirds of the energy we
normally use goes to support basal metabolism, the resting, continuous metabolic work of body
Signals That Start and Terminate a Meal
Glucose: a simple sugar that is the body’s major source of immediately usable fuel.
• Some glucose is transported into cells to provide energy
• Large portion of glucose is transferred into the liver and fat cells, where it is converted
into other nutrients and stored for later use.
• When blood glucose levels are low, the liver responds by converting stored nutrients back
• Stomach and intestinal distention
o The walls of these organs stretch as food fills them up, sending nerve signals to
the brain. o Nutritionally rich food seems to produce satiety more quickly than an equal
volume of less nutritious food. Therefore, some satiety signals respond to food
o Patients who have had their stomach removed continue to have satiety signals
because of intestinal distention.
• Respond to food by releasing several hormones, called peptides, that help terminate the
o CCK (cholecystokinin): released into the bloodstream by the small intestine as
food arrives from the stomach. It stimulates regions of the brain that decreases
Signals That Regulate General Appetite and Weight
Leptin: a hormone that decreases appetite.
• As we gain fat, more leptin is secreted into the blood and reaches the brain. Leptin signals
influence neural pathways to decrease appetite and increase energy expenditure.
• It does not make us feel full like CCK, leptin regulates appetite by increasing the potency
of these other signals.
• High leptin levels may tell the brain “There is plenty of fat tissue, so it’s time to eat less”.
Lateral hypothalamus= “hunger on” centre
• Stimulation of LH will cause someone to eat
• Lesioning of LH will cause someone to refuse to eat (to the point of starvation)
• LH damage causes a trouble swallowing and digesting, and one becomes unresponsive to
external stimuli (not just food).
Ventromedial hypothalamus= “hunger off” centre
• Stimulating VMH will cause someone who is hungry to stop eating
• Lesioning VMH will produce glutons who ate frequently and doubled or triples their
Paraventricular nucleus (PVN): a cluster of neurons packed with receptor sites for various
transmitters that stimulate or reduce appetite.
• PVN Y is a powerful appetite stimulant
• When leptin reaches the hypothalamus, it seems to inhibit the activity of neurons that
release neuropeptide Y into the PVN, and therefore appetite is reduced.
• When there is a loss of fat, less leptin is secreted and therefore neuropeptide Y neurons
become more active, increasing appetite.
Psychological Aspects of Hunger
• Attitudes, habits, and psychological needs regulate food intake
• “don’t leave food on your plate” and “autopilot” snacking while watching TV
• Food restriction in women stems from social pressure Objectification theory: Western culture teaches women to view their bodies as objects, much as
external observers would.
Environment and Cultural Factors
Environmental regulators of eating:
1. Food availability: food scarcity limits consumption, and abundant low-cost food
contributes to high rate of obesity.
2. Food taste and variety: good-tasting food positively reinforces eating and increases food
consumption, and food variety increases consumption.
3. Smell and sight of food: when your nose detects the sensuous aroma we desire food
even if we aren’t hungry.
4. Presence of other: we typically eat more when dining with others because meals take
5. Cultural norms: influence when, how, and what we eat. The time that is “normal” to eat
dinner varies from society to society.
6. Familiarity of food: we feel more comfortable eating foods we are familiar with.
Genes and Environment
• Heredity influences our basal metabolic rate and tendency to store energy as either fat or
• Genetic factors account for 40-70% of the variation in body mass among women and
• An abundance of inexpensive, tasty, high-fat foods available almost everywhere
• A cultural emphasis on “getting the best value”, which contributes to the “supersizing” of
• Technological advances that decrease the need for daily physical activity encourages a
Excessive Exercise: Activity Anorexia
If a rat is allowed limited access to food and unlimited access to a running wheel except during
the meal period, a condition called activity anorexia develops. Over days, animals with access to
running wheel engage in increasing amounts of running; they eat less, lose weight, and, if left in
the situation will starve.
• Animals developed CTA (conditioned taste aversion) to novel (new) food, but did not to
The Battle to Control Eating and Weight
• The smell, sight, and even sound of a favorite food can stimulate the release of the
hormone insulin. Insulin stimulates the transfer of glucose from the blood into the cells of
the body, and an increase in insulin leads to rapid drop in blood glucose levels. • Weight loss through diet is due to a loss of both lean body mass and fat, whereas weight
loss through exercise is due to a loss of fat.
• If weight is lost through exercise, there is a consequent increase in the ratio of muscle to
fat, and that generally leads to an increase in basal metabolic rate. Heightened basal
metabolism will help to burn calories, even when you are not exercising.
The Psychology of Sex
Sexual response cycle: four-stage cycle
1. Excitement phase: arousal build rapidly, blood flow increases to arteries in and around
the genital organs, nipples, and women’s breasts, pooling and causing these body areas to
swell (this process is called vasocongestion). The penis and clitoris begin to become
erect, the vagine becomes lubricated, and muscle tension increases throughout the body.
2. Plateau phase: respiration, heart rate, vasocongestion, and muscle tension continue to
build until there is enough muscle tension to trigger orgasm.
3. Orgasm phase: in males, rhythmic contractions of internal organs and muscle tissue
surrounding the urethra project semen out of the penis. In females, orgasms involves
rhythmic contractions of the outer third of the vagina, surrounding muscles, and the
4. Resolution phase: In males, physiological arousal decreases rapidly and the genital
organs and tissues return to their normal condition. During the resolution phase, males
enter a refractory period during which they are temporarily incapable of another orgasm.
Females may have two or more successive orgasms before the onset of the resolution
• The hypothalamus controls the pituitary gland, which regulates the secretion of hormones
called gonadotropins. These hormones affect the rate at which the gonads secrete
androgens (testosterone) and estrogens.
• Organizational effects that direct the development of male and female sex characteristics.
• Activational effects that stimulate sexual desire and behaviour.
• Sexual fantasies alone may trigger genital erection and orgasm in some people.
Desire, Arousal, and Sexual Dysfunction
• Psychological factors can contribute and inhibit sexual arousal
• Stress, fatigue, and anger at one’s partner can lead to temporary arousal problems.
• Sexual dysfunction: chronic, impaired sexual functioning that distresses a person. It may
result from injuries, diseases, and drug effects, but some causes are psychological.
Cultural and Environmental Influences
Predicting pornography’s effects:
• Social learning theory: people learn through observation. • Catharsis principle: as inborn aggressive and sexual impulses build up, actions that
release this tension provide a “catharsis” that temporarily returns us to a more balanced
• Violent pornography increases men’s aggressive behaviour toward women.
• Pornography promotes that sex is impersonal and decreases vieweers’ satisfaction with
their own sexual partners.
• The belief that sex is impersonal contributes to rape.
Sexual orientation: one’s emotional and erotic preference for partners of a particular sex.
Determinants of Sexual Orientation
• No particular phenomenon of family life can be singled out for either homosexual or
• The closer the genetic relatedness, the higher the concordance rates for sexual orientation
• Some believe, the brain develops a neural pattern that predisposes organisms to prefer
either female or male sex patterns
• Some believe, altering prenatal exposure to sex hormones can influence sexual
• There is no clear evidence that prenatal sex hormones directly affect human sexual
• It is possible that heredity affects sexual orientation only indirectly by influencing
children’s basic personality style.
Need for achievement: represents the desire to accomplish tasks and attain standards of
excellence. It is a relatively stable personality characteristic that energizes and guides our
Motivation for Success: The Thrill of Victory
People thrive to succeed for two different reasons:
1. Motive for success
• Mastery goals: reflect intrinsic motivation (“I want to learn as much as possible
from this class” and “I prefer course material that arouses my curiosity, even if it
is difficult to learn”)
• Performance goals: involve social comparison (“I am motivated by thought of
outperforming my peers in this cla