Thinking, Problem Solving and Bias

Two ways to solve a problem

An algorithm tries every possibility — guaranteed to work, but slow. A heuristic is a mental shortcut — fast, usually right, occasionally badly wrong.

The biases that show up on the exam

• Availability heuristic — judging likelihood by how easily examples come to mind. Plane crashes are vivid, so people overestimate air travel risk.
• Representativeness heuristic — judging by how well something matches a stereotype, ignoring base rates.
• Confirmation bias — seeking evidence that supports what you already believe.
• Framing — the same fact stated as "90% survive" or "10% die" produces different choices.
• Anchoring — the first number offered drags later estimates toward it.
• Functional fixedness — seeing an object only in its usual role.
• Hindsight bias — "I knew it all along" after learning the outcome.
• Overconfidence — being more certain than accuracy warrants.

Intelligence

$\text{IQ}$ scores are standardised with a mean of $100$ and a standard deviation of $15$, so about $68\%$ of people score between $85$ and $115$. A test must be both reliable (consistent) and valid (measuring what it claims).