A beard or long hair for men has always been a sign of rejection of conforming to social authority.

Hair is the best symbol of rebellion as it is difficult to defect from, takes a long time to grow long, and is accessible to everyone. You can recognize a hippie with their tie-dye shirt and reflective sunglasses. They signal to themselves and others that they are opposed to the Vietnam war and the establishment in general. But when they go to the office, for a swim, to the gym, etc. they go back to conforming to the rest of society. The hippie with long hair is at all times signaling their rejection to the establishment and is also signaling that they have been rejecting this for many years. The hippie who only commits to the tie-dye shirt and sunglasses can take it off when under scrutiny and put it back on when convenient.

Hair has no nerve cells. Cutting hair is completely painles. If someone won’t even listen to authority telling them to cut their hair, what makes you think they’ll listen to authority for anything else? Long hair subconsciously scares authority because the legitimacy of said authority is constantly challenged. This is my hypothesis for why being clean shaven and short hair has become a requirement in many militaries, but never a militia. It is the easiest way to get someone to subconsciously be comfortable with submitting to authority.

Some examples of "beardos" who use their hair as a symbol of rebellion:

• Koreans during Japanese Imperialism
• The Khalsa
• Indian saints, regardless of religion
• Hippies in the US
• Brazilian communists during the dictatorship