In psychological conditioning, the Law of Effect was proposed by Edward Lee Thorndike, an American Psychologist of the late 19th and early 20th century, who studied animal intelligence in detail. According to the Law of Effect, when the result of a stimulus-response situation brings pleasure and satisfaction to the animal, that response gets fixed onto the situation and is likely to repeat when the same situation occurs again. On the other hand, the response of the situation that brings pain and discomfort to the animal develops weaker connection with that particular situation and is unlikely to repeat with the reoccurrence of the situation. Moreover, the greater the degree of pleasure the stronger the connection of the response with the situation (and vice versa). This implies that learning and behavioural patterns of animals are controlled by reward and punishment, which could be determined by controlled experiments.
The Law of Effect was coined by the psychologist Edward Lee Thorndike. The Law of Effect is used in psychological conditioning, more specifically, operant conditioning. The Law of Effect basically states that a response to a stimulus will be fixed and will occur again when that stimulus is presented again. In other words, this shows that reinforcement reinforces behavior and punishment reduces behavior. In addition, this shows that reinforcement is a more effective way of conditioning than punishment is.
This law states that when in a situation, the response produced is satisfying, then the same thing is likely to occur again in that situation, and less comforting reactions are less likely to occur. In turn, it is similar to the evolutionary theory where if a character trait is helpful for reproduction is will remain.