Studies Of End Effect From The Perspective Of Perceived Difference Of Stimulus

The Peak-End effect,which refers to such a phenomenon that the retrospective evaluation of certain stimulus or things is mainly decided by the peak and end momentary ratings,is a decision bias commonly existed.Especially,when it comes to the end effect,it usually means an extra weaker stimulus added to the end of certain stimulus,which leads to a greater total but a reduced evaluation in valence.Considering this,the end effect is the focus of present study.Theory of Judgment by Prototype,Mental Account and weighted average have been used to explain the Peak-End effect.Based on studies from these explanations,the present study suggested that all those theories point to a same direction,namely the perception of the varied difference brought by the stimulus added to the end.Taking air pollution as the object,this research first explored whether the end effect could be observed,then studied the effect of perceived difference on end effect.Experiment 1 first explores the end effect.Two trails of pictures that stand for air pollution were presented one after another using e-prime,among which one consisted of 30 heavy polluted pictures and the other contained extra 15 middle polluted pictures.The result indicated that people showed more liking for the long trail and more willing to experience it again,which kept accordance with previous research.Experiment 2 further explored the effect of perceived difference on end effect in emotional and behavioral response,using the same procedure with experiment 1 but by adjusting the valence difference between the added pictures and the added-before ones.The results showed that when the added pictures were the same with added-before ones in pollution level,people tended to choose the short trail,which meant the end effect disappeared,however,when the added pictures were middle polluted ones,people still preferred to the long trail,which meant the end effect worked.This contrary chooses indicated that the end effect may rely on the perceive difference of stimulus.Experiment 3 confirmed the influence of perceived difference on end effect by using different cognitive tasks.In experiment 3,which used the same materials with experiment 1 but added a data to every picture to stand for the pollution severity,one group of subjects were asked to judge whether the experienced picture could be defined as air pollution while the other to classify them into different levels.The result showed that those who carried out the category task were more possible to choose the long trail,which provided evidence for the saying that the end effect may rely on the perceived difference.However,when it come to the preference within groups,those who went on category task did not show any difference between the short and long trail.This implied that cognition task could only reduce the bias brought by end effect.The present study explored the end effect using air pollution as materials,which had at least two active significance.One was proving the end effect in the evaluation of air pollution,expanding the research fields of the peak-end effect.The other was providing a useful view to intervene the impression formation of people on air pollution.What’s more important,the present study directly pointed out the influence of perceived difference on end effect,which provided a new perspective to understand it.Last,the present study discussed some shortages and lighted some inspiration for future research.