Theory of Social Impact
Bibb Latanè has been involved actively in trying to understand the influence of others on social behavior. His early work with John Darley demonstrated that people are less likely to help someone in an emergency if there are other people around. The concept of diffusion of responsibility explains the bystander effect by saying that responsibility for helping is equally distributed among all of the people present. Hence, if you are alone, the responsibility of helping or not helping is totally yours, but if you are one of four people, only 25 percent of it is yours. Latanè has also investigated the phenomenon of social loafing, which states that in a group of people each one contributes less than he or she would contribute alone. He found that when eight people clapped their hands, the sound was not eight times as loud as the sound of each one individually, and that in a game of tug-of-war the force was not multiplied by the number of people pulling on the rope. Latanè combined much of his research into a new theory called the theory of social impact. There are several principles included in this theory. First, the more people present, the more influence they will have on each individual. Additionally, the more important the people are to the individual, the more influence they will have on him or her. Second, the theory of social impact states that while the impact of others on the individual increases as the number of people increases, the rate of increase in impact grows less as each new individual is added. For example, if you are giving a presentation to three people and a fourth one joins the group, this is more significant than if you were giving a presentation to 31 people and one more joined. Third, each individual can influence others; but the more people are present, the less influence any one individual will have. Thus, we are more likely to listen attentively to a speaker if we are in a small group than if we were in a large group. Latanè has tested his theory of social impact in a variety of situations. In his 1981 paper, he reports that people tip more if they have separate bills than if they share in a group bill. In parties of six, if each person is given an individual bill, the tipping is about 19 percent, while in groups of six with a group bill, each individual contributes only about 13 percent. In another study, Latanè tested the hypothesis that television evangelist Billy Graham would be more effective in front of small audiences. He researched the numbers of people who responded to Graham's appeal for converts in various-sized audiences. He found that when the audiences were small, people were more willing to sign cards allowing local ministers to contact them than when the audiences were large. Social psychologists are just beginning to research the theory of social impact (Jackson, 1987). Already it has made many predictions that could be useful in understanding human behavior. Further research will test the validity of these predictions.