Learning is reinforced, and the shorter the interval, the better
For ESP testing, it’s important to give immediate feedback to tap into people’s ability to learn and improve. Slow feedback could actually reduce someone’s ESP abilities (since it’s an extinction method.)
Almost all learning takes place in situations where the correct response is rewarded on each trial and incorrect responses are not rewarded, or may even be punished.
… Almost all studies of learning show that learning is slower and less effective as the interval between response and reward increases. With lower organisms, particularly, a fairly lengthy interval between response and reward results in no learning at all, i.e., the organism never emits the correct response with greater than chance frequency. In general, intervals between response and reward or feedback are optimal if they are of less than a second, and learning falls off rapidly in many instances if these intervals reach even a few seconds.