The source of the catfish effect:

Origin 1: Norwegians like to eat sardines, especially live fish. The price of live fish in the market is much higher than that of dead fish. Therefore, fishermen always try their best to get sardines back to the fishing port alive. However, despite all the efforts, most of the sardines still died of suffocation in the process. But there is a fishing boat that can always bring most of the sardines back to the fishing port alive. The captain closely guarded the secret. It wasn't until the captain's death that the mystery was revealed. It turned out that the captain put a catfish whose main food was fish into the fish tank filled with sardines. After the catfish enters the fish tank, it swims around because of the unfamiliar environment. The sardines were very nervous when they saw the catfish, darted left and right, hid in all directions, and swam faster. In this way, the problem of hypoxia of sardines will be solved, and the sardines will not die. In this way, the sardines returned to the fishing port alive and kicking. This is the famous "catfish effect."

Origin 2: Like the "theory" of boiling frogs in warm water, it is a deception theory originating in China in the 1980s and 1990s, but it became an imported product after being spread falsely.

Remarks:

1. Catfish is an active fish, and there is nothing very special about it. However, since fishermen used it as a tool to ensure the survival of sardines transported over long distances, the role of catfish has been increasingly valued.

2. Sardines like to be quiet and pursue stability by nature. Without a clear understanding of the dangers he faces, he just takes comfort in his current life. The fisherman cleverly used the catfish's restless nature to keep the sardines alive, and in the process, he also gained maximum benefit.