Why Wedding Ring is Worn Over 4th Finger?

When your hands are as such do this:

Pull your thumbs apart. (this represents the parents) Your thumbs will open because you and your parents are not destined to be together forever. At some point they will leave you in your life. Now put your thumbs back together.

Repeat the same motion with your index fingers (this representing your siblings). Of course your index fingers will also separate because you are also not destined to be with your siblings for the rest of your life. They will move on and have families of their own. Now put them back together.