‘Social Psychology’ is defined as the scientific and logical investigation of how an individual’s feelings, thoughts, and behavior is affected by the individuals around them and how an individual may feel, think, and behave towards other people around him. Social psychology experiments to study group behaviour were being conducted in as early as before the year 1900.

These experiments were conducted to logically, scientifically, and systematically measure and record the feelings, behaviors, attributes, thoughts, patterns, and attitudes of social behavior among human beings. By the year 1908, the first social psychology textbooks were published. These include several books written on an introduction to social psychology which outlines the principles which govern the field of social psychology.

The social psychologists, Kurt Lewin and Leon Festinger helped establish social psychology as a strictly scientific discipline and developed the need for experimentation and its approaches to studying behavior during the years 1940s and 1950s. Lewin is also known as “the father of social psychology” as he was responsible for developing several important ideas on social psychology on the dynamic interactions among groups.

During the Second World War, social psychologists tried to analyze and understand how Adolf Hitler was able to produce such massive and large-scale impact and gather obedience from masses to create such horrors on other people of their own same species or humans.