Peak-end rule
The researchers concluded that the most unpleasant, the peak, and the final intensity of unpleasantness, the end were used to evaluate the procedure. In this case, the end of Group B is less unpleasant. At the same time, the peak of both Group A and Group B were the same. Thus, the sum of the unpleasantness of the peak and the end was less for Group B. As a result, participants from Group B found the experience less unpleasant, although for both the duration of and the sum of unpleasantness, Group A < Group B.