Concept: The Yerkes-Dodson Law posits an empirical relationship between arousal (including stress) and performance. It suggests that performance increases with physiological or mental arousal, but only up to a point. When levels of arousal become too high, performance decreases.
Application: Learning engineering practitioners must design interventions to ensure the cognitive load and challenge level of a task create an optimal level of arousal. Tasks that are too easy lead to boredom and low effort (low arousal), while tasks that are too difficult can lead to anxiety and withdrawal (high arousal/distress).