Final answer:
The classic Festinger et al., (1950) research conducted at MIT was about social pressures in informal groups and how they influence decision-making and individual behavior.
Step-by-step explanation:
The classic Festinger et al., (1950) research conducted at MIT was about social pressures in informal groups. This study aimed to investigate human factors in housing and how social pressures influence decision-making within groups. Festinger and his colleagues examined how group members conform to each other's expectations and how these social pressures affect individual behavior. The researchers found that people often conform to group norms and make decisions based on social pressures, even if it goes against their personal beliefs or preferences.