AP Psychology 4.6: Motivation

Your body works to keep conditions inside it steady, such as its temperature and how much water it holds. Keeping that balance is homeostasis. Drive-reduction theory says a physical need, such as a lack of water, creates a drive: an uncomfortable state of tension that pushes you to act. Acting reduces the drive and brings the body back toward balance. Thirst after a long run sends you to the fountain, and drinking makes the urge fade.

Drive reduction is one of the theories that start from the body's physical needs and desires. It explains a lot of eating, drinking and getting warm. It has trouble with behavior that raises tension instead of lowering it, such as riding a roller coaster on a full stomach.

Many animals are also moved by instincts: innate, typically fixed patterns of behavior that appear in response to certain stimuli, without being learned. A spider spins its species' web the first time it tries. Sea turtles crawl toward the ocean as soon as they hatch.

Humans do not seem to show instinctual behavior or mental processes in this sense. People are born with reflexes, such as a newborn's rooting reflex, but a reflex is one simple response to one stimulus, while an instinct is a whole pattern of behavior, like spinning a web. Even things that come easily to people, such as courting a partner or comforting a baby, differ across cultures and are shaped by learning.

Drive reduction cannot explain someone with every need met who goes looking for something to do. Arousal theory says people seek an optimal level of arousal, a level of alertness and activation that is neither too low nor too high. When arousal is too low you feel bored and look for stimulation, and when it is too high you look for calm.

The Yerkes-Dodson law links arousal to performance. People perform best at a moderate level of arousal, and performance falls off when arousal is too low or too high, so a graph of it is an upside-down U. The best level depends on the task. An easy or well-practiced task holds up under more arousal, and a difficult task peaks at a lower level of arousal than an easy one does.

People also differ in how much stimulation they need. Sensation-seeking theory says a person's level of need for varied or novel experiences is the basis of their motivation. It names four types:

• Experience seeking: new experiences of the mind and senses, such as unfamiliar food, music or places.
• Thrill or adventure seeking: physically risky, exciting activities, such as skydiving.
• Disinhibition: seeking excitement by letting go of social restraint, such as at a wild party.
• Boredom susceptibility: a strong dislike of routine and repetition, and restlessness when things stay the same.

Some motivation comes from outside you. Incentive theory looks at how rewards motivate behavior: a paycheck, a prize, a good grade or praise pulls you toward whatever earns it. A reward is an extrinsic motivation, a reason that comes from outside the activity itself.

Self-determination theory says people are motivated by intrinsic or extrinsic motivations. Intrinsic motivation is internal: doing something for its own sake, because it is interesting or satisfying. Extrinsic motivation is external: doing it for something outside it, such as a reward. The same activity can rest on either. One student practices piano because she loves the sound, and another practices only because her parents pay her for each hour.

Goals can also collide. Lewin's motivational conflicts theory says choices create conflicts that you must resolve, and that this is the basis of motivation. Each option either attracts you (approach) or repels you (avoidance).

• Approach-approach: two options you want, and you can have only one. Two concerts you love on the same night.
• Avoidance-avoidance: two options you do not want, and you must take one. Cleaning the garage or weeding the yard.
• Approach-avoidance: one option that both attracts and repels. A job that pays well but starts at 5 a.m.

Eating is a complex motivated behavior, and it shows how physical and mental processes interact. Hunger looks like a simple drive, but when you eat, and how much, depends on signals from inside the body and cues from outside it.

Inside, hormones carry the signals. Ghrelin is a hormone that brings on feelings of hunger. Leptin is a hormone that brings on satiety, the feeling of having had enough. Both hormones carry their messages to the hypothalamus, the part of the brain that regulates hunger and fullness, which works closely with the pituitary gland.

Outside, the situation matters. The presence of food can start eating with no hunger at all: a plate of cookies on the counter gets eaten because it is there. The time of day sets off eating too, so people feel ready for lunch at noon partly because noon is when they usually eat. Social gatherings around meals, such as holiday dinners, birthday parties and team cookouts, lead people to eat when the group eats and as the group eats.

Those gatherings point to a second motive, the need to belong: to be accepted by and connected with other people. It moves behavior, as when a new student joins a club mainly to find friends, and it moves thinking, as when someone left out of a group chat keeps replaying it and wondering what they did. A shared meal often answers hunger and belonging at once.