Yerkes-Dodson Law

The Yerkes-Dodson law, formulated in 1908 and refined through a century of subsequent work, describes the inverted-U relationship between arousal and cognitive performance. Performance improves as arousal increases up to an optimum, beyond which further arousal causes performance to decline. The curve's shape varies with task complexity: simple tasks tolerate higher arousal, complex tasks require lower arousal and degrade more steeply past the optimum. The law was descriptive rather than mechanistic — Yerkes and Dodson identified the pattern without explaining it — but transient hypofrontality provides the mechanism. The prefrontal cortex has its own arousal-performance curve, steeper and narrower than the general curve, operating optimally within a restricted band of norepinephrine and dopamine concentration.