Behavioural economics characterises decision-makers using psychologically-informed models. Cognitive science produces psychologically-informed models. Why don’t these disciplines talk more? Here, the author presents several arguments for why cognitive science should inform behavioural economics – it characterises internal psychological states, builds a richer conception of human nature, pays equal attention to cognition’s successes and failures, embraces multidisciplinary insights, and avoids blind spots produced by behavioural economics’ intellectual lineage. The author illustrates these principles using the cognitive science of sense-making – how humans understand information – including mental tools such as heuristics, stories and theories.