Why should the wedding ring be worn on the fourth finger?

Why should the wedding ring be worn on the fourth finger? There is
a beautiful and convincing explanation given by the Chinese.....

Thumb represents your Parents
Second (Index) finger represents your Siblings
Middle finger represents your-Self
Fourth (Ring) finger represents your Life Partner
& the Last (Little) finger represents your children

Firstly, open your palms (face to face), bend the middle fingers
and hold them together - back to back
Secondly, open and hold the remaining three fingers and the thumb -
tip to tip (As shown in the figure to the right):

Now, try to separate your thumbs (representing the parents)...,
they will open, because your parents are not destined to live with
you lifelong, and have to leave you sooner or later.

Please join your thumbs as before and separate your Index fingers
(representing siblings)...., they will also open, because your
brothers and sisters will have their own families and will have to
lead their own separate lives.

Now join the Index fingers and separate your Little fingers
(representing your children)...., they will open too, because the
children also will get married and settle down on their own some day.

Finally, join your Little fingers, and try to separate your Ring
fingers (representing your spouse).
You will be surprised to see that you just CANNOT....., because
Husband & Wife have to remain together all their lives - through
thick and thin!!