When an action results in a pleasurable consequence, the probability of repeating that action increases. this best illustrates?

This best illustrates " Thorndike's Law of Effect"

In 1905 this psychological principle was presented by Edward Thorndike that if an acts generates an effect which results in pleasure the act will be repeated and if it does not result in pleasurable consequences, the act will not be repeated. Edward Thorndike advanced this by experimenting on animals by creating puzzle boxes and escaping from them.