Impact of the other bystander’s likelihood of helping on the global Bystander Effect

When a victim is in need, people are less likely to help when there are other persons present. In general, this means that the probability of helping decreases in negative correlation to the number of bystanders affected. In social psychology literature, researchers refer to this phenomenon as the individual Bystander Effect. From another perspective, the decreased probability for the victim to receive help by each additional bystander is called the global Bystander Effect. The purpose of the paper at hand is to predict the global Bystander Effect by use of a model. The model shows that depending on the perceived probability that the other bystander will help the Bystander Effect can be found. According to my model, a perceived high likelihood of helping of the other bystander decreases the bystander’s tendency to help when comparing one potential helper to the same circumstance with another person present. Hence, the global Bystander Effect exists. A perceived low likelihood of the other bystander’s willingness to help leads to the opposite outcome where no group size effects emerge. Both hypotheses were tested in a lab experiment using the standard dictator game and an adapted version of it by increasing the number of dictators/bystanders from one to two. Moreover, the experiment was conducted with two treatment groups: one where all bystanders were very likely to help and one where most bystanders were unlikely to help. Even though the results revealed the predicted pattern, it was not proved to be significant at a reasonable level. Besides that, I found that women were more likely to provide help than men in all decision rounds