Basic Motivational Concepts

LOQ: How do psychologists define motivation? From what perspectives do they view motivated behavior?

Our motivations arise from the interplay between nature (the bodily “push”) and nurture (the “pulls” from our personal experiences, thoughts, and culture).

• Motives drive behavior

• If our motivation gets overridden, our lives go crazy

There are four different perespectives to understand motivation behavior

• Instinct theory (now replaced by the evolutionary perspective) focuses on genetically predisposed behaviors.

• Drive-reduction theory focuses on how we respond to our inner pushes.

• Arousal theory focuses on finding the right level of stimulation.

• Abraham Maslow’s hierarchy of needs focuses on the priority of some needs over others.

Motivation: a need or desire that energizes and directs behavior

Instincts and Evolutionary Theory

To become an instinct, a complex behavior must have a fixed pattern throughout a species and be unlearned

• unlearned human behaviors include such as infants’ innate reflexes to root for a nipple and suck, also exhibit unlearned fixed patterns.

• Instinct theory viewed our instincts as the source of our motivation

  • Many more behaviors are directed by both physiological needs and psychological wants.

instincts cannot explain most human motives the main assumption endures in evolutionary psychology

• Genes do predispose some species-typical behavior

Instinct: a complex behavior that is rigidly patterned throughout a species and is unlearned.

Drives and Incentives

With our predispositions we also have drives

• Physiological needs (such as for food or water) create an aroused, motivated state—a drive (such as hunger or thirst)—that pushes us to reduce the need

• Drive-reduction theory explains that, with few exceptions, when a physiological need increases, so does our psychological drive to reduce it.

Drive reduction is one way our bodies strive for homeostasis

• Ex. our body regulates its temperature in a way similar to a room’s thermostat

• Both systems operate through feedback loops

  • Sensors feed room temperature to a control device

We are pushed by our need to reduce drives, we also are pulled by incentives

• Given such stimuli, our underlying drives, such as for food or sex, become active impulses

• he more those impulses are satisfied and reinforced, the stronger the drive may become

Physiological: need a basic bodily requirement.

Drive-Reduction Theory: the idea that a physiological need creates an aroused state (a drive) that motivates an organism to satisfy the need.

Homeostasis: a tendency to maintain a balanced or constant internal state; the regulation of any aspect of body chemistry, such as blood glucose, around a particular level.

Incentive: a positive or negative environmental stimulus that motivates behavior.

Arousal Theory

Some motivated behaviors actually increase rather than decrease arousal

• Ex. Well-fed animals will leave their shelter to explore and gain information, seemingly in the absence of any need-based drive.

Human motivation aims not to eliminate arousal but to seek optimum levels of arousal

• With all our biological needs satisfied, we feel driven to experience stimulation.

  • With little stimulation, we feel bored and look for a way to increase arousal

• given too much stimulation or stress, we look for a way to decrease arousal.

Yerkes-Dodson law: the principle that performance increases with arousal only up to a point, beyond which performance decreases.

A Hierarchy of Needs

Abraham Maslow described these priorities as a hierarchy of needs

• At the base of this pyramid are our physiological needs, such as for food and water

  • Only if these needs are met are we prompted to meet our need for safety and then to satisfy our needs to give and receive love and to enjoy self-esteem.

  • The order of the heirachy is not universally fixed

• Near the end of his life, Maslow proposed that some people also reach a level of self-transcendence

  • people seek to realize their own potential and strive for meaning, purpose, and communion in a way that is transpersonal

Hierarchy of Needs: Maslow’s pyramid of human needs, beginning at the base with physiological needs that must first be satisfied before higher-level safety needs and then psychological needs become active.

Hunger

The Physiology of Hunger

LOQ: What physiological factors produce hunger?

Semistarved volunteers felt their hunger because of a homeostatic system that maintains one’s normal body weight and an adequate nutrient supply

A.L. Washburn and Walter Cannon worked together to find out what triggers hunger

• Washburn decided to swallow a balloon attached to a recording device

  • He then supplied information about his feelings of hunger by pressing a key each time he felt a hunger pang.

  • The result was that when Washburn felt hungry, he was indeed having stomach contractions.

Body Chemistry and the Brain

People and other animals automatically regulate their caloric intake to prevent energy deficits and maintain a stable body weight.

• This shows that within the body something is making notes of all the resources in the body

  • Blood sugar glucose is one of these

Increases in the hormone insulin (secreted by the pancreas) diminish blood glucose

• When your blood glucose level drops, you won’t consciously feel the lower blood sugar but your brain will trigger hunger signals

The work is done by several neural areas, some housed deep in the brain within the hypothalamus

• Ex. d the arcuate nucleus) has a center that secretes appetite stimulating hormones

  • When stimulated electrically, well-fed animals begin to eat. If the area is destroyed, even starving animals have no interest in food.

  • Another neural center secretes appetite-suppressing hormones. When electrically stimulated, animals will stop eating. Destroy this area and animals can’t stop eating and will become obese

Blood vessels connect the hypothalamus to the rest of the body, so it can respond to our current blood chemistry and other incoming information

• ghrelin, a hunger-arousing hormone secreted by an empty stomach

  • During bypass surgery for severe obesity, surgeons seal off or remove part of the stomach. The remaining stomach then produces much less ghrelin, and the person’s appetite lessen

  • Insulin, ghrelin, leptin, orexin, and PYY are appetite hormones

Increase Appetite

• Ghrelin: Hormone secreted by the empty stomach; sends “I’m hungry” signals to the brain.

• Orexin: Hunger-triggering hormone secreted by the hypothalamus.

Decreases Appetite

• Insulin: Hormone secreted by the pancreas; controls blood glucose.

• Leptin: Protein hormone secreted by fat cells; when abundant, causes the brain to increase metabolism and decrease hunger.

• PYY: Digestive tract hormone; sends “I’m not hungry” signals to the brain.

You can also blame your brain for weight regain

• The complex interaction of appetite hormones and brain activity helps explain the body’s predisposition to maintain a particular weight

• Heredity influences body type and approximate set point

Our bodies regulate weight through the control of food intake, energy output, and basal metabolic rate

• They reduced their energy expenditure, partly through inactivity but partly because of a 29 percent drop in their basal metabolic rate.

Some researchers, however, doubt that our bodies have a preset tendency to maintain optimum weight

• point out that slow, sustained changes in body weight can alter one’s set point, and that psychological factors also sometimes drive our feelings of hunger

• some researchers prefer the term settling point to indicate the level at which a person’s weight settles in response to caloric intake and expenditure

Glucose: the form of sugar that circulates in the blood and provides the major source of energy for body tissues. When its level is low, we feel hunger.

Set Point: the point at which your “weight thermostat” may be set. When your body falls below this weight, increased hunger and a lowered metabolic rate may combine to restore lost weight.

Basal Metabolic Rate: the body’s resting rate of energy output