Thinking, Problem Solving & Decision Making
- Distinguish algorithms from heuristics in problem solving
- Identify common cognitive biases that distort judgment
- Explain how framing and fixation influence decisions
Concepts, algorithms, and heuristics
We organize knowledge into concepts — mental categories — often anchored by a prototype, the best example of a category (a robin is a prototypical bird). To solve problems we use two broad strategies. An algorithm is a step-by-step procedure that guarantees a solution but can be slow (trying every letter combination to unscramble a word). A heuristic is a mental shortcut that is faster but error-prone (starting with likely letter pairs). We also get flashes of insight — sudden realization of a solution, the "aha!" moment studied by the Gestalt psychologists.
Heuristics that mislead: Kahneman and Tversky
Daniel Kahneman and Amos Tversky catalogued shortcuts that systematically bias judgment. The availability heuristic judges likelihood by how easily examples come to mind — vivid plane crashes make flying feel more dangerous than driving. The representativeness heuristic judges probability by resemblance to a prototype, ignoring base rates (assuming a quiet reader is "a librarian" rather than the far more numerous "salesperson"). These fast judgments usually serve us well but predictably fail in ways the exam loves to test.
Obstacles: fixation, framing, and belief
Several forces block good thinking. Fixation is the inability to see a problem from a fresh angle; mental set is the tendency to approach problems the way that worked before, and functional fixedness is seeing objects only in their usual use (not realizing a coin can be a screwdriver). Confirmation bias leads us to seek evidence that supports our beliefs and ignore what contradicts them. Framing shows that how a choice is worded sways decisions: "90% survival" and "10% mortality" describe the same odds, yet people choose differently. Belief perseverance keeps beliefs alive even after the evidence is discredited.
After watching several news stories about shark attacks, a vacationer refuses to swim in the ocean, convinced attacks are common, even though the statistical risk is minuscule. Identify the cognitive bias and explain the reasoning error.
- 1.Identify what drives the fear: the vivid, memorable news stories are easy to recall.
- 2.Match to the heuristic: judging how likely something is by how easily examples come to mind is the availability heuristic.
- 3.Explain the error: mental availability (dramatic, well-publicized attacks) is mistaken for actual frequency, so a rare event feels common.
- 4.Note the correction: the real base rate of shark attacks is extremely low, but the emotionally vivid examples override the statistics.
A researcher tries to open a locked box and never thinks to use the metal ruler on the desk as a pry bar, because she sees the ruler only as a measuring tool. This difficulty best illustrates:
Keep the two heuristics distinct: availability = judging by how easily examples come to mind (vividness/frequency), representativeness = judging by how well something matches a prototype (ignoring base rates). Ask whether the clue is "easy to recall" or "fits a stereotype."
A surgeon tells patients a procedure has a "90% survival rate," and far more agree to it than when a colleague describes the identical procedure as having a "10% death rate." This difference is best explained by:
On FRQs, tie each bias to a one-line trigger: availability = vivid/easily recalled examples, representativeness = matches a stereotype, confirmation bias = only seeking supporting evidence, framing = same facts worded differently. Naming the trigger nails the definition point.
Answer the 2 checkpoints as you read.
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