John Henry effect please see Compensatory rivalry.

The John Henry effect is a psychological phenomenon that refers to the tendency for people to work harder and more diligently when they are competing against a machine or other automated system, as opposed to another human being. The effect is named after the folk hero John Henry, who is said to have competed against a steam-powered drill and won, only to die from exhaustion shortly afterward.

The John Henry effect has been observed in a variety of contexts, including in the workplace, where employees may work harder when faced with the threat of being replaced by a machine. It can also be seen in sports, where athletes may perform better when competing against a rival as opposed to a computer program.

One example of the John Henry effect might be a person who is working on an assembly line and is trying to keep up with a machine that is performing the same task. Another example might be a student who studies harder for a test when they know they will be competing against a classmate rather than just trying to beat their own previous score.