why we shake hands???

This is very interesting. i think we do it as a sign of friendship. Its like giving someone a pat on the back or a hug, but it's just more formal. I only shake hands with older people like my employers though. Otherwise I just say hello and wave my hand. I think a smile is enough to show friendship to someone. I'm not a big fan of shaking hands because I imagine the germs that transfer from one hand to the other. You won't really know what the other person has been holding, right?

It's part of a social practice to shake hands especially in formal gatherings where people are introduced or meet the first time. There is really no hard and fast reason...I guess it's a practice that is passed on from generations. Instead of asking why we should shake hands, we should instead ask, what's wrong with shaking hands? It's most appropriate and there's really nothing wrong with it.