Presence of other people change an individual's behavior? Norman Triplett
One of the seminal social-psychology studies, at the turn of the 20th century, asked a question that at the time was a novel one: How does the presence of other people change an individual's behavior?
Norman Triplett, a psychologist at Indiana University, found that when he asked children to execute a simple task (winding line on a fishing rod), they performed better in the company of other children than they did when alone in a room. Over the following decades, a new discipline grew up within psychology to further interrogate group dynamics: how social groups react in certain circumstances, how the many can affect the one.
The field reached a moment of unusual visibility in the mid-20th century, as practitioners, many of them Jewish refugees or first-generation immigrants from Europe, explored, post-World War II, the way group pressures or authority figures could influence human behavior.
In one simple study on conformity in 1951, the social psychologist Solomon Asch found that people would agree that one drawn line matched the length of another -- even if it clearly did not -- if others around them all agreed that it did.
In subsequent years, researchers like Stanley Milgram (who tested how people weighed their consciences against the demands of authority) and Philip Zimbardo (who observed the effect of power on students assigned as either prison guards or prisoners) rejected the traditional confines of the lab for more theatrical displays of human nature. "They felt the urgency of history," says Rebecca Lemov, a professor of the history of science at Harvard. "They really wanted to make people look."