The Event Feature And The Optimism Bias

Optimism bias defines the tendency for human beings to underrate risk when it pertains to themselves compared with their view of risk pertaining to other people in the same conditions.By information / belief updating task,the degree to which participants updated their personal risk estimates from initial to second is measured.The present study attempts to improve the updating task by using more reasonable base rate,to explore differences between positive events and negative events on the optimistic bias.Another part of the study is to explore how the event valence of controllability and enjoyment for positive events influence optimism bias.The update method asks participants to estimate their chance of experiencing a series events and then gives the base rate of those events.After told the average possibilities,participants are asked to re-estimate their own chance of these events.The asymmetry that people alter their beliefs in response to good news than bad news,which are divided by the difference between the first estimation and the base rate,means the optimism bias.In experiment one,there were 41 college students,including 20 undergraduates and 21 graduate students,included in the study.It's a 2(event type: positive,negative)× 2(message type: good news,bad news)within subject design.In experiment two,the same research paradigm and dependent variable index were used to investigate whether the controllability and enjoyment of events could affect the optimism bias of positive events,with another 42 college students.We use a 2(event controllability: high controllability,low controllability)×2(event pleasure degree: high pleasure degree,low pleasure degree)×2(message type: good news,bad news)within subject design.The results of the first experiment showed that under the condition of positive events,the belief updating on the good news was significantly higher than that on bad news,and same with the result under the condition of negative events.However,the asymmetry in belief updating has no significantly difference between positive events and negative events.The ANOVA in the second experiment showed that in all types of events,the asymmetry between updating beliefs for desirable and undesirable information exists.Participants on all kinds of controllability and enjoyment events,updated their beliefs more for desirable information than undesirable information.However,participants had a greater asymmetry to more controllability events in belief updating than less controllability events,and a greater asymmetry to more enjoyment events in belief updating than less enjoyment events.Conclusions:(1)Optimism bias was stable both on general positive life events and general negative life events,and the optimism bias degree on these two kinds of events have no difference.(2)The optimism bias exists in all general positive life events,and the feature of the event effectively affect the degree of optimism bias.The subjects had higher optimism bias to less controllability positive events and more enjoyment positive events.Meanwhile,the subjects appear lower optimism bias to more controllability positive events and less pleasure positive events.