Deciding quickly is difficult when we face information and choice overload so in much of our everyday decision-making we use quick rules. ‘Quick thinking’ explores some of these rules—heuristics—and the consequences of using them. Sometimes heuristics work well, but sometimes they lead us into errors and mistakes. Psychologists Daniel Kahneman and Amos Tversky explore three main heuristics and the associated behavioural biases: availability, representativeness, and anchoring and adjustment. The availability heuristic can explain our habitual behaviours. Employing the representative heuristic, we match our judgements with our knowledge of prior scenarios and stereotypes. Anchoring/adjustment occurs when we anchor our decisions around a reference point, and adjust our choices relative to it.