Chatgpt says it’s 4 parts: social norms, practicality, religious and cultural significance and fashion.

This seems like a reasonable nuanced set of reasons.

Text:

The hairstyles of men and women have varied significantly across cultures and time periods, and the idea that men should have short hair while women should have long hair is not a universal one. However, in many Western societies, short hair for men and long hair for women has been the norm for several centuries. This is likely due to a combination of social, practical, and cultural reasons.

1. **Social Norms and Gender Roles**: Historically, long hair in many societies was seen as a symbol of femininity and beauty in women, while short hair in men was often associated with masculinity and strength. These norms may have been reinforced by societal expectations and gender roles.

2. **Practicality**: There were also practical reasons for men to keep their hair short, especially in certain occupations. For instance, soldiers and warriors often had short hair to prevent it from being a liability in battle (an enemy could grab a warrior's long hair). Similarly, for manual laborers, shorter hair was more practical and safer. Conversely, women, who have historically been tasked with domestic roles, did not have these same constraints.

3. **Religious and Cultural Significance**: In many cultures and religions, hair length has significant symbolism. For example, in certain Christian sects, the Apostle Paul's writings in the New Testament were interpreted to mean that women should have long hair as a "covering" and sign of submission, while men should have short hair.

4. **Fashion and Aesthetics**: Fashion trends have played a big part in hair length norms as well. For example, in the 1920s, the bob cut became popular for women, which was a radical departure from the norm. In the 1960s and 1970s, it became more acceptable for men to grow their hair long.

It's worth noting that these norms have been changing and continue to change. Nowadays, there is much more acceptance of people choosing to wear their hair at any length they prefer, regardless of their gender. Men can have long hair, and women can have short hair, and both are socially acceptable in many societies.