In 1908 psychologists Robert Yerkes and John Gillingham Dodson found that increasing stress and arousal helps focus attention and improves motivation for the task at hand but only up to a certain point.

1. The Yerkes—Dodson Law
Stress (up to a point) improves performance

2. In 1908 psychologists Robert Yerkes and John
Gillingham Dodson examined the effect of stress and
arousal on attention and motivation
They presented rats with a maze which had one right
way through

4. If the rats went the wrong way they got an electric shock

6. Increasing the intensity of the electric shock improved
the rate of learning among the rats up to a point

8. Beyond a certain voltage the rats’ performance started
to decrease – they slowed down, froze, retreated and
forgot where was safe and where was dangerous

10. Conclusion
Increasing stress and arousal helps focus attention
and improves motivation for the task at hand but
only up to a certain point

11. Further studies demonstrated this effect in humans but
showed that the ‘breaking point’ varies depending on the
type of task
We see this effect in athletic performance

12. When a tennis player is about to make an important
serve, a degree of tension will sharpen their focus and
improve their performance – they may serve an ace
However if the player gets too stressed out, they’ll lose
concentration and perform worse – they may double fault

13. If I miss this,
that’s the end of my
tournament…

14. Performance
Stress
Too much stress –
performance deteriorates
Increasing stress –
performance improves

15. A swimmer about to race 50m is harder to ‘stress out’
Their task is direct and uncomplicated – swim as fast
as they can

16. Let’s do this!

17. Performance
Stress
Tennis player
Swimmer
Optimum level of stress
for peak performance

18. Conclusions
1. People performing simpler tasks can withstand a higher
degree of stress before performance deteriorates
2. All tasks (and individuals) have an optimum point of
stress at which performance will peak, beyond this point
increasing stress hinders performance

19. Reference
Relation of Strength of Stimulus to Rapidity of Habit-formation
Robert Mearns Yerkes and John Dillingham Dodson
1908 Journal of Comparative Neurology and Psychology