Participants and protocol
Participants (N = 63) were assigned to two conditions for the hindsight bias test (HBT); 32 participants (Mean age 22.6 years, SD = 2.93, 20 women) were assigned to the HIGH list (HIGH) and 31 (Mean age 22.8 years, SD = 2.33, 20 women) to the LOW list (LOW) condition. The desired power level was 0.80, and the minimum effect size calculated by G*Power was 0.71. The HIGH and LOW conditions consisted of 50 and 20 questions, respectively. The HIGH condition consisted of 20 identical questions to the LOW condition and an additional 30 unique questions. The authors developed these HBT questions based on preliminary discussions and pilot trials. The HBT items used in the two conditions were included in supporting information (The LOW and HIGH conditions differed only in the number of correct answers to be remembered (i.e., 20 versus 50), which we defined as MLOIE. Therefore, we used the data of the 20 questions in the HIGH condition that was identical to the LOW condition to compare the MLOIE effect on hindsight bias between the two conditions after eliminating the potential effect of different questions on hindsight bias. Two indices were developed and compared between the LOW and HIGH conditions to test the hypothesis. First, the hindsight bias index (%) was calculated as defined (initial responses—recollection values) / (initial responses—correct information). Second, the distorted items (%) were calculated as the number of distorted items divided by the number of all the items. All the questions were made available to answer in numbers, given that the amount of hindsight bias can also be estimated as numerical values.