When studying research relating to the ‘diffusion of responsibility’, Latane and Darley carried out a study in which students in separate rooms discussed personal problems through an intercom. The discussion was between either two, three or six person groups. During the discussion, one of the participants simulated an epileptic attack. It appears that diffusion of responsibility also occurs in non- serious situations. Latane and Dabbs (1975) conducted 1500 trials with almost 5000 bystanders. In these situations, a person would, for example, drop coins or pencils in a lift. As predicted by the diffusion of responsibility hypothesis, results showed that the probability of helping behaviour in stage three- the probability of helping decreased with the number of bystanders present.
When considering ‘Pluralistic Ignorance’, Darley et al (1973) found that bystanders who stood face-to-face with other bystanders were more likely to help in an emergency than those who stood back to back. They concluded that the effects of pluralistic were stronger when in the back-to-back condition as bystanders were unable to see each others facial expressions, so were deprived of important interpretative cues.
Secondly, the arousal: cost-reward model by Piliavin et al (1981) suggests that when people come across someone in need, they work their way through various stages before they respond or walk away. The first requirement is for the bystander to experience physiological arousal. When we see someone in distress, we become physiologically aroused. This arousal is unpleasant so we are motivated to reduce it. The greater the arousal, the more likely it is that a bystander will help. When people are in a state of personal distress, they are motivated to do something about it, but first costs and benefits have to be calculated. This means weighing up the costs of helping against the costs of not helping. The benefits of helping must also be taken into great consideration.
A famous study relating to the arousal: cost-reward model called the ‘Subway Samaritan’ was carried out by Pallavin et al (1969). In this, one confederate collapsed on a New York subway train while observers recorded how many passengers offered to help. They found that the more people in the carriage, the more likely help was forthcoming. When the confederate appeared to be blind, help was quicker and more likely than when he appeared to be drunk, showing that deservingness was a critical characteristic of the victim. The costs of helping and not helping were studied by Clark (1976) in which students were asked to read to a blind student for five hours. The costs of helping were varied- students had to travel either long (high cost) or short (low cost) distances in order to carry out the task. The costs of not helping were also varied in that the blind student was either preparing for an important examination or completing part of his normal learning programme. The likelihood of students agreeing to help was higher when their costs were low and the costs of not helping were high. Helpfulness was much lower in all other conditions.
Many studies of bystander behaviour suffer from the same problems as studies of Altruism- they use studies of psychology students as participants, and some of the experimental set-ups may lack believability. There have, however, been a number of field experiments of bystander behaviour and such experiments have their pros and cons. The behaviour studied is real-life behaviour, and since participants are not aware of participating in an experiment, they do not change their behaviour in response to experimental cues. On the downside, it is more difficult to control extraneous variables. Moreover, field studies have also shown that people who are not in a laboratory tend to behave differently, which means that many of the laboratory findings reported may well lack ecological validity.