Human psychology, neuroscience and behavioural economics study the human mind, brain and behaviour. Scientific research has discovered a great deal about the factors that influence human perception, judgment and activity in the real world. In this article, I aim to provide an outline of the relationship between decision-making, cognition, emotion and behaviour. I propose that meta-cognition, or thinking-about-thinking, has the potential to inform how we practice emergency medicine. By accommodating human traits rather than trying to defy them, we can ultimately benefit our patients.