Yerkes & Dodson were the psychologists who defined the Yerkes-Dodson Law in the early 20th Century.
This theory shows that human performance and learning of new skills varies with ‘arousal’ level. Arousal means interest, excitement or stress- a certain amount is good and increases ability to learn, but too much and performance begins to deteriorate. There are some classic graphs that demonstrate this- here is a link to a website that explains it in simple terms and gives the original reference too.
I chose this subject for my Y post as I thought it links quite closely with the concept of ‘flow’ (see F) used in occupational therapy. Flow occurs when someone is fully engaged in an activity, the activity needs to have the right balance of challenge and skill, so a certain amount of stress is involved- flow will not occur of the task is boring, but too much stress i.e. the task is too difficult, and flow will not occur either.
Whether we think of it as the Yerkes-Dodson Law or as the concept of ‘flow’, these are both ways of helping us understand the importance of pitching activities at the right level if they are to be effective, and that level will be different for every individual.