The catfish effect is the effect that a strong competitor has in causing the weak to better themselves.

In Norway, live sardine

Sardine

Sardines, or pilchards, are several types of small, oily fish related to herrings, family Clupeidae. Sardines are named after the Mediterranean island of Sardinia, around which they were once abundant....

s are a few times more expensive than frozen ones. It was said that only one ship could bring live Sardine home, and the ship master kept his method a secret. When he later died, people found that there was one catfish

Catfish

Catfishes are a diverse group of ray-finned fish. Named for their prominent barbels, which resemble a cat's whiskers, catfish range in size and behavior from the heaviest and longest, the Mekong giant catfish from Southeast Asia and the second longest, the wels catfish of Eurasia, to detritivores...

 in the container. The catfish keeps swimming and the sardine becomes very active to avoid direct contact with this Catfish.

In human resource management

Human resource management

Human Resource Management is the management of an organization's employees. While human resource management is sometimes referred to as a "soft" management skill, effective practice within an organization requires a strategic focus to ensure that people resources can facilitate the achievement of...

, this is a method used to motivate a team so that each member feels a strong competition, thus keeping up the competitiveness of the whole team.

Origin of the effect

The exact origin is unknown. There are very few discussions of this effect in the English literature, but it is widely cited and discussed in the Chinese literature such as library research.