In 1908, Robert Yerkes and John Dodson discovered that performance on a task is related to arousal (stress/motivation) level — but not in a simple linear way. The relationship forms an inverted U-curve.

The Law

• Too little arousal → low performance (boredom, under-engagement)
• Optimal arousal → peak performance (engaged, focused, challenged)
• Too much arousal → declining performance (anxiety, cognitive overload, panic)

Task Complexity Matters

The optimal arousal level varies by task difficulty:

• Simple, well-practiced tasks perform best with higher arousal
• Complex, unfamiliar, or cognitively demanding tasks perform best with lower arousal

Applications

• Sports: Pre-competition anxiety management — elite athletes seek the zone, not the peak of stress
• Management: Deadlines and pressure improve performance to a point, then degrade it rapidly
• Exams: Moderate test anxiety sharpens performance; severe anxiety collapses it
• Surgery: Surgeons perform best on familiar procedures under moderate time pressure — not rushed, not casual

Reference:

Wikipedia: Yerkes-Dodson Law

https://en.wikipedia.org/wiki/Yerkes%E2%80%93Dodson_law