Numerous studies have been conducted to demonstrate the Bystander Effect. These are results from a few of these studies...
The Effects of group size on helping (Fiske, 2004, pp. 320).
Figure 4 demonstrates the findings of four studies conducted by Latané and Darley.
The Smoke Filled Room-
The subjects were placed in a room alone or in groups of three with other subjects or confederates. They were then asked to fill out some preliminary questions. Soon smoke was pumped into the room through an air vent. Students who were alone reported the smoke 75% of the time, 38% of the students in groups of three acted and only 10% when the subjects were in the presence of two confederates who appeared oblivious to the smoke.
The subjects were placed in a room to fill out a survey. During this time they heard a chair fall over and a woman's scream accompanied by claims of being hurt, moaning and crying. Subjects were either placed alone, with a passive confederate, with another subject they did not know or with another subject who they were friends with. 70% of all subjects offered to help. However only 7% of the subjects in the passive confederate condition intervened.
Money Theft (Hand in the till)-
Whilst awaiting an interview, male graduates were witness to a theft (actually a confederate), in one condition the subject was the sole witness and in another, two subjects were present. The 'thief' took money from an envelope on the receptionist's desk, placed it in his pocket and sat back down, when the receptionist left the room. Despite the obviousness of the crime, many subjects claimed they had not noticed the crime. 52% of the subjects who were in the alone condition claimed they had not noticed the theft, while 25% of the Together pairs said that had not noticed.
The robbers (confederates) either in a pair or singly entered the store and whilst the cashier is out back, they walk out the door with a case of beer. This is conducted when either one or two people are in the store and at least one of them at the counter. On the cashier's return, the number of bystanders who; spontaneously mentioned the robbers (20%), reported the crime after prompting from the cashier (51%) and did not report it at all were measured.
Figure 4. Percentages of Single Subjects or Group Helping (Latané & Darley, 1970, pp. 88).
Figure 5 further demonstrates the results of the Smoke Filled Room Experiment.
Figure 6 depicts the bystander effect in relationship to violent theft. Evidently, this is an issue due to the failure for people to act.