Motivation and Emotion
Motivational theories and concepts
- motives are the needs, wants, interests and desires that propel people in
- Motivation involves goal-directed behaviour
- Goals and our motivation to achieve them are often important characteristics
of successful adjustment.
Drive theories (clark hull)
- drives are also known as motivational forces.
- Walter cannon observed that organisms seek to maintain homeostasis, a
state of physiological equilibrium or stability.
- A drive is an internal state of tension that motivates an organism to engage in
activities that should reduce this tension.
- When individuals experience a drive, they are motivated to pursue it in order
to reduce the drive.
- Example: you can go without food for a while with some discomfort, but as
time passes the internal tension (the drive) motivates you to get food. By
eating, you reduce the tension and restore physiological equilibrium.
- external stimuli regulate motivational states.
- An incentive is an external goal that has the capacity to motivate behavior.
- Examples of this are ice cream, monetary prize, A on an exam and promotion
- drive theories emphasize how internal states of tension push people in
- incentive theories emphasize how external stimuli pull people in certain
- Drive theories motivation lies within the organism whereas incentive
theories motivation lies in the environment.
- Incentive theories emphasize environmental factors and downplay the
biological bases of human motivation.
- Expectancy-value models: ones motivation to pursue a course of action will
depend on 2 factors: (1) expectancy about one’s chances of attaining the
incentive and (2) the value of the desired incentive.
- Example is a promotion is the expectancy and the appeal of it to the person is
- human motives and of other species are products of evolution.
- Natural selection favours behaviours that will maximize reproductive
success. - Biological motives: hunger, thirst, sex, temperature, sleep
- Social motives: achievement, affiliation, dominance, order
- Power (dominance) and intimacy affect reproductive success.
Motivation of hunger and eating (biological factors in regulation of hunger)
- hunger focuses on the role of the brain, blood sugar level and hormones.
- experiences of hunger is controlled from the brain. Specifically the 2 centers
in the hypothalamus known also for control of the body’s survival.
- When animals’ lateral hypothalamus (LH) was lesioned, they showed no
hunger. In contrast, when the ventromedial nucleus of the hypothalamus
(VMH), they gained weight and ate excessively.
- LH and VMH are elements in the neural circuitry that regulates hunger. The
paraventricular nucleus (PVN) contains a group of neurons that are sensitive
to incoming hunger signals and another group of neurons that respond to
- These circuits rely on neurotransmitters such as Neuropeptide Y and
serotonin and GABA and ghrelin.
- Ghrelin stimulates hunger. More intake increase hunger.
Glucose and Digestive Regulation
- food is converted into glucose, which then circulates in the blood. Glucose is a
simple sugar that is an important source of energy. A decrease in blood sugar
can increase hunger.
- Glucostatic theory says that fluctuations in blood glucose level are monitored
in the brain by glucostats- neurons sensitive to glucose in the surrounding
- The digestive system can also influence hunger. After you have consumed
food, cells in the stomach can send signals to the brain that inhibit further
- the secretion of insulin is associated with increased hunger. The sight and
smell of food can stimulate the secretion of insulin and play a role in
fluctuation of hunger.
- Leptin, a hormone, is produced by fat cells and released into the blood
stream. High levels of fat generate more leptin, it then circulates throughout
the bloodstream and provides the hypothalamus with info about the body’s
- When leptin is high, the feeling of hunger diminishes. Leptin activates
receptors in the brain that release of neuropeptide Y, which leads to activity
in the paraventricular nucleus of the hypothalamus, which leads to eating.
Food availability and related cues - the availability and palatability of food are the key factors in regulating
hunger (incentive). The presence of tasty food leads people to eat more even
though they are already quite full.
- Sensory specific satiety: As you eat more of a specific food, the incentive
value declines. If more new foods are available you will eat more as the
incentive increases. (example buffets)
- Environmental cues can also trigger hunger such as, television food
commercials, seductive odours from the kitchen.
- Social cues also trigger hunger such as the social behaviour of others.
Example: being around others makes you eat it all depends on the behviour
Learned preferences and habits
- preferences are acquired through learning such as something that you have
been eating your whole life like chips has been accustomed to you. Different
people from different cultures have different patterns of food consumption.
- Humans have innate taste preferences. Sweet tastes at birth, salt tastes at 4
- Conditioning plays a role from our past experiences. When you go to a
hockey game you go straight for the hot dog stand because it is natural for
you as you have done it many times in the past.
- Young children will try unfamiliar foods if the adult tries it first. Repeated
exposure to new food often leads to increased liking.
Stress and eating
- stress leads to increased eating. Stress-induced physiological arousal and
negative emotions often evoke additional eating.
- Emotional distress is responded to by eating tasty foods because they are
enjoyable treats to make them feel better.
Eating and weight: roots of obesity
- obesity is the condition of being overweight.
- Body mass index is an individuals weight (KG) divided by height (m
squared). BMI between 25-29.9 are overweight
- Obesity is a significant health problem that elevates one’s mortality risk.
- Overweight people are vulnerable to cardiovascular diseases, diabetes,
hypertension, respiratory problems, gallbladder disease, stroke, arthritis,
muscle and skeletal pain and types of cancer.
- Humans’ evolved tendency to overeat when food is plentiful leads most
people down a pathway of chronic, excessive food consumption.
- identical twins had similar bmi compared to fraternal.
Excessive eating an inadequate exercise - overweight peoples’ energy intake from food consumption exceeds their
energy expenditure from physical activities and resting metabolic processes.
- Increased availability of highly caloric food in north America has caused the
declining of physical activity. Technology and modern conveniences had
made our lifestyles more sedentary.
Concept of set point
- people who lose weight on a diet have a rather strong tendency to gain back
all of the weight they lose.
- Set point theory proposes that the body monitors fat cell levels to keep them
fairly stable. When fat stores slip below a crucial set point, the body begins to
compensate for the change. This leads to increased hunger and decreased
- Settling point theory proposes that weight tends to drift around the level at
which the constellation of factors that determine food consumption and
energy expenditure achieves an equilibrium.
- Weight tends to remain stable as long as there are no durable changes in any
of the factors that influence it.
- chronic dieters are restrained eaters- people who overly focus on controlling
their eating impulses and feel guilty when they fail.
- Dietary restraint contributes to obesity and overeating.
- Restrained eaters are also sensitive to the media’s portrayal of ideal thin
- anorexia nervosa- disorder where young women starve themselves to death
- bulimia nervosa- young women result in binge eating or purging (vomit to
- women are most likely to suffer from eating disorders as they are majorly
impacted by social and media pressures.
- sex is essential for the survival of a species but not individual survival.
- More younger children are beginning to participate in sex, some even
- hormones are secreted by the gonads- ovaries in the female and testes in
males-which can influence sexual motivation.
- Estrogens are the principal class of gonadal hormones in females. Androgens
are the principal class on gonadal hormones in males.
- The hypothalamus and pituitary gland regulate these hormonal secretions.
- Gonadal hormones regulate sex drives in animals.
- Androgen levels are related to sexual motivation in both sexes. Higher levels
of testosterone correlate with higher rates of sexual activity. - Conclusion: hormonal fluctuations have a small impact on sexual drives.
Evolutionary analyses of human sexual beha