While Social Psychology was first mentioned in the late 19th century, it became a subject of serious study thanks to the Second World War, after psychologists realised that existing theories could not understand or predict why people behaved the way they did in the war.
The first new social psychology studies were used for fairly unethical (although arguably useful) purposes; they were commissioned by the military to find out how types of influence such as persuasion and propaganda worked. After the war ended, they began to study social problems such as racism and gender imbalance, later moving on to subjects like aggression. Their focus on human problems meant their studies needed to be conducted on humans, leading to years of horribly unethical experiments, until the invention of a new system of ethical guidelines in 1961, after the Nuremberg Trials
The most controversial psychology experiments have often been on obedience and conformity. Annoyingly, they are the also the ones which have told us most abut human behaviour.
One of the most famous social psychologists is Stanley Milgram: his obedience experiment is possibly the most-known experiment in psychology, and often the first thing psychology students learn about.
After WW2, most people believed that they would never do the cruel things the Nazis did, leading to the general belief that Germans were somehow “different”- that they were much more obedient than “normal” people.
Milgram’s study tested this “Germans were different” hypothesis by asking participants to give electric shocks to another participant for answering questions wrongly, until they reached a level of electric shock severe enough to kill the other participant. (Don’t worry, the shocks were fake…and so was the guy they were given to.)
When Milgram planned the study, the experts he consulted believed that fewer than 1/1000 people would shock up to the dangerous level (300v) and nobody would go to the death level (450v). In the actual study, 100% of people went to 300v, and 65% went to 450v-meaning 65% of people wound up believing they had just killed someone.
The important part is that the study wasn’t even done on German people- it was on Americans, the people who believed they would never be that obedient. Despite how stressful the experiment was, and people’s reactions to knowing they had potentially killed someone (one man had to be removed from the experiment with stress-induced convulsions), the participants involved were glad to have taken part, and almost all of them said they had gained important knowledge from it.
Although the experiment was incredibly unethical, in one way it can be seen as necessary; without the experiment happening, people would have continued to believe that Germans were the only people able to obey to the point of murder. This vewipoint could have potentially created widespread prejudice and hatred towards German people.
Milgram then went further with this experiment, trying to find what affected how much people obeyed. He also studied anti-social behaviour and prejudice, and came up with the “Six Degrees of Separation” concept. However, while he was doing this, other psychologists such as Asch and Zimbardo had begun to perform equally controversial studies.