Why do muslims wear head-scarves?

Heas scarves are more cultural than religious. Although for women it is recommended that they should cover their head with cloth, so their beauty can only be seen by their closed ones, like a jewel. In my opinion, even there are christians in India, Arab countries and Pakistan who wear head scarves, so it is not religious, it is cultural thing. I can be wrong but this is my opinion and I believe in it.