When did the men start cutting their hair short and why?

Men began cutting their hair short in various cultures at different times, but a significant shift occurred in the early 20th century, particularly during World War I. The military favored short hairstyles for practicality and hygiene, as they were easier to maintain and less likely to harbor lice. This trend continued into the 1920s and 1930s as short hair became associated with modernity and professionalism. Over time, short haircuts became a symbol of masculinity and social conformity.