Mass hysteria is a psychological phenomenon where a group of people experiences similar symptoms or behaviors, often without a clear physical cause. This can include feelings of anxiety, panic, or even physical ailments that spread through a community. The phenomenon often occurs in stressful situations, where individuals may influence one another's reactions. Historically, mass hysteria has been observed in various contexts, such as during the Salem witch trials or in schools where students report fainting or illness simultaneously. These episodes highlight how social dynamics and collective emotions can lead to widespread, irrational behavior among groups of people.