How did people cut their hair in the Stone Age?

In the Stone Age if a person wanted to cut their hair they probably first used sharp stones or animal bones. Later, once flint knives were created, they could use the sharper edge. Another option is obsidian glass. The few well-preserved remains of humans from the Stone Age show that most of the women would keep their hair long and braided. The men would keep their hair very short or be completely bald. Getting a close shave back then would take a lot of trust!

https://medium.com/@monikaindustryofficial/how-did-people-cut-hair-before-scissors-fb04dd6da49b
https://www.thenakedscientists.com/articles/questions/did-cavemen-cut-their-hair