Are you familiar with this feeling? When you experience a little bit of stress, you perform highly. But when you’re too stressed, life feels really strenuous or you shut down. Conversely, when you’re not experiencing any stress at all, it’s difficult to feel motivated. 

There’s a phrase for this phenomenon. It’s called Yerkes-Dodson Law, and the Yerkes-Dodson theory has been around since the early 1900s.

What does the Yerkes-Dodson Law state?

Yerkes-Dodson Law states a correlation between stress (referred to as arousal) and performance. It explains that an optimal level of arousal corresponds to an optimal level of performance. Generally, this relationship is displayed as an upside-down U-shaped stress curve.

Simply stated, Yerkes-Dodson Law suggests that increased stress helps improve performance, but only to a certain point. The Yerkes-Dodson graphic shows this relationship through the stress performance curve. When stress and arousal are low, productivity is low. As stress and arousal grow, productivity grows until its peak in the middle of the stress bell curve. From that point, increased stress and arousal result in a declining performance.

Yerkes-Dodson theory is also related to the concept of eustress vs. distress, or the terms explaining the different types of stress. Eustress is “challenging, but rewarding” and manageable stress (the middle of the stress curve), and distress leads to difficulty in getting started and inability to cope (the left and right sides of the stress productivity curve).

What does the Yerkes-Dodson Law tell us about the level of anxiety and learning?

Yerkes-Dodson Law tells us that there is an optimal level of anxiety and stress, which lies somewhere in the middle of the stress bell curve.

If you’re responsible for easy tasks, you can complete them at a wide range of anxiety levels. If you’re not aroused (or anxious) enough, you may lose interest or fall asleep. Alternatively, you may lose focus and feel too overwhelmed if you’re over-aroused (or anxious).

Studies show that in a learning environment, the stress curve shows us that a slight amount of stress (but not too much or too little) will result in enhanced performance in learning. Therefore, classrooms and training environments should operate with just enough pressure to put students and team members in the middle of the stress performance curve.

If you extrapolate this concept to a work environment, with a healthy amount of stress, you can perform at a high level for long periods of time. However, there is a tipping point. Once over the top of the curve, stress can negatively impact your performance.

Where did Yerkes-Dodson Law originate?

Yerkes-Dodson Law originated in 1908 as a paper documenting experiments in Japanese dancing mice. Robert Yerkes and John Dodson released their findings on how responses varied to different stimuli explained by the Yerkes-Dodson theory. 

The experiments delivered electric shocks to the mice upon entering a white box. When the mice moved to a black box next to the white box, the mice would not receive a shock. In their first experiments, Yerkes and Dodson delivered shocks low in intensity. With the weak shocks, the mice took longer to form a habit of choosing the black box (with no shocks).

As Yerkes and Dodson increased the intensity of the shocks, the mice learned the habit in fewer shock trials. However, the strongest electric shock intensity received a puzzling result. The mice again took more time forming the pattern of choosing the black, non-shocking box.

Researchers Yerkes and Dodson would run more sets of experiments–each with animals, boxes, and shock stimuli–but varying the task’s difficulty by making it easier and harder to discern between the white and black boxes. The results were that very weak and very strong shocks can result in slow patterns of habit formation. It also showed that the optimal stress level could depend on the nature of the task (or the difficulty).

Thus, the Yerkes-Dodson theory was born and the stress curve was formed.

Hebb’s concept of arousal and the “U-shaped curve” caused a resurgence of interest in Yerkes-Dodson Law in the 1950s. Hebb stated an idea similar to Yerkes-Dodson theory that the words “fear, anxiety, emotionality, tension, drive, and arousal” can be used interchangeably to explain motivation.

What are the criticisms of the Yerkes-Dodson Law?

Some researchers have since criticized Yerkes-Dodson Law for poor experimental design and lack of consideration for personality type and managerial training.

Scholars have criticized all of the three experiments for being inconsistent between variables. Scholars claim that using varying levels of stimuli, subjects, and conditions invalidates the research. The studies have also received criticism for over-assuming stress’s effects on people with different personality types (like extroverts vs. introverts) and in varying environments of managerial training.

Despite its criticisms, those with real-world experience in burnout and stress can certainly attest to the impact of stress on motivation, learning, and performance.

The moral of the Yerkes-Dodson Law is that there is an optimal stress level for optimal performance, as seen in the stress bell curve. It’s also true that the optimal stress level will vary from person to person or task to task and can also depend on the type of stress and environmental factors. Finding the “sweet spot” of optimal stress level on your personal stress performance curve is a journey that can improve your productivity once learned.

For high-achievers who want to stay consistently motivated while avoiding burnout and improving productivity, we’ve got the help you need! Choose from our e-learning programs to study the best way to manage stress and burnout, and achieve a happier life.