Think about head hair. Everyone says it exists to keep our heads warm.
But as skin colour has adapted to the sun, head hair remains, from the Inuits to the Arabs to the Melanesians. Why?
Maybe head hair actually has a ‘helmet effect’ where it deflects/absorbs hits to the head. It would be evolutionarily adaptive. if you look at hair, it covers the area of the brain neatly (except the forehead).
This theory could even explain why men have facial hair, if they are more likely to be hit in the face, in battle, fights, etc. It’s not a totally crazy theory: eyebrow hair exists for a protective effect.
If you are a scientist, please test this hypothesis. I imagine a series of experiments with sharp and blunt trauma, with direct and glancing blows. (Warning! : The ethics committee might not like it if you use a real head – get a wig and a mannequin instead.)
The results might be useful in improving helmet design. Imagine if the Bret Mckenzie hair helmet was legislated!
That is all.