The myth and theory about "long hair giving you power" may …

The myth and theory about "long hair giving you power" may be wrong.
I think its the opposite and based on the handicap-principle and signal-theory.
Its an external signal, that you are so strong and your ability to fight so good, that you even can afford to grow your hair long. Which normally is a disadvantage in a fight, especially in close combat.
Sonin my opinion the theory makes more sense backwards: long hair could only be afforded by the best and most powerful fighters.
This is why today a lot of theories suggest, that long hair gives you special abilities. Maybe thats true as well, but I think the handicap-principle as an underlying reason makes more sense.
This may also be the reason why samurai had to cut their hair when defeated. It was analagous and symbolical for death and that the fighter lost and couldn't afford the long hair. Cutting the hair of was a peaceful compromise instead of death. Similar to a dog showing his throat.