social impact theory

• Suggests that there’s three situational factors that affect social impact which therefore makes people obedient. One of them is strength of the source, this includes seeing the source as someone of a higher status, age, or a legitimate authority making us obey. Immediacy involves proximity of source and targets, we are more likely to obey orders when instructed from a closer proximity as the social impact increases and we feel the pressure more compared to if they were instructing from further away or through phone, text, indirectly.
• number or sources compared to number of targets, the more sources there are, the higher the social impact and therefore more obedience however, this only works for sources up to the 3 as the number of sources is divided by the number of targets, this is known as the divisional effect, so the more sources there the lower the social impact. This can be explained by the psychological law in terms of a light bulb, one bulb in a dark room will have a great impact, a second bulb will make it brighter but the more bulbs you add the less impact each additional one will have.
• All three situational factors are put into one simple formula: social impact = f(SIN) this is the multiplicative effect suggesting that an increase in any one of the factors would cause more social impact on the targets.
• One strength of this theory is that there is evidence supporting the effect of the three situational factors. In Milgram’s telephonic instructions variation, he made the experimenter give instructions to the teacher through the phone, telling the participant to continue administering shocks. He found that obedience levels decreased significantly as the participants would say they’re giving the shocks but, would not obey.
• strength - Obedience went from 65% in Milgram’s original experiment down to only 22% obedience in this variation. This is a strength as it shows how a decrease in immediacy caused a weaker social impact and therefore more evidence supporting the multiplicative effect. As a decrease in one of the factors would cause an overall decrease in social impact.  
• A weakness is that it is very reductionist by cancelling down complex human behaviours down to a simple formula. Social impact= f(SIN) suggesting that an increase in any of these situational factors will cause an increase in obedience. However, it doesn’t consider personality or cultural factors that could also affect obedience e.g., people with an external locus of control are more likely to obey than people with an internal locus of control as they tend to believe that their consequences are their own responsibility, and they oversee their own actions.