2.2 Thinking, Problem-Solving, Judgments, and Decision-Making

A concept is a mental grouping of similar things, events or people, like 'bird' or 'sport.' A prototype is the best or most typical example of a concept. For many Americans, a robin is a prototype bird, so they'd say 'yes, a robin is a bird' faster than 'yes, a penguin is a bird.'

A schema is a broader framework for organizing information. You can take in new information in two ways. Assimilation means fitting new information into an existing schema without changing it, like a toddler who calls every four-legged animal 'doggy.' Accommodation means changing the schema to fit the new information, like the toddler learning that cows are a separate category. Piaget used these terms for children's development (3.4), but you use them your whole life.

An algorithm is a step-by-step method that tries every possibility until it finds the answer. It guarantees a solution but can be slow. Trying every combination on a three-digit lock is an algorithm. A heuristic is a mental shortcut. It's fast and usually works, but it can lead to errors.

• Representativeness heuristic: judging how likely something is by how well it matches your prototype or stereotype. If you meet a quiet person who loves books, you might guess they're a librarian rather than a salesperson, even though there are far more salespeople. This shortcut can lead to stereotyping.
• Availability heuristic: judging how likely something is by how easily examples come to mind. After seeing news coverage of a plane crash, people often overestimate the danger of flying, even though driving is far riskier per mile.

• Mental set: sticking with a method that worked before, even when a better one exists. If you've solved ten math problems with one formula, you may keep using it on an eleventh where it doesn't fit.
• Priming: earlier exposure to something unconsciously affects how you respond later. Seeing the word 'yellow' makes you faster to recognize 'banana.'
• Framing: the way a choice is worded changes the decision. People are more likely to choose a surgery described as having a '90% survival rate' than one with a '10% death rate,' even though they're identical.
• Gambler's fallacy: believing that past random events change the odds of future ones. After five coin flips land heads, many people think tails is 'due,' but the chance is still 50%.
• Sunk-cost fallacy: continuing something because of what you've already invested (money, time or effort) rather than whether it's worth continuing. Sitting through a terrible movie because you paid for the ticket is a classic example.

Executive functions are the mental processes that let you set goals, organize, plan, focus, control impulses, switch between tasks and think critically. They depend heavily on the prefrontal cortex, which keeps developing into a person's mid-20s.

Creativity is producing new and useful ideas. It relies on divergent thinking, which generates many possible answers ('How many uses can you think of for a brick?'). Convergent thinking narrows in on one correct answer, as on a multiple-choice test. Both are useful, but creativity depends more on divergent thinking.

Functional fixedness blocks creativity. It is the tendency to see objects only in their usual function. If you need to tighten a screw but don't have a screwdriver, and you never think of using a coin, you're showing functional fixedness.