Where does a package get more damaged?

As I was sitting here waiting for a package to arrive, I began to wonder where in shipping does most of the damage happen.  Is there a specific shipping method that is better?  Is there a specific service that is better?  Or does each shipping method have flaws?

Take for instance 1 or 2 day shipping.  These quick methods rush your packages from the point of shipping to the destination.  With all this movement, there is probability that the company is switching between vehicles quickly, which would cause them to be less careful to fulfill the shipping requirements.  They must get the package to you within the quoted time.

On the flipside, those shipping methods that take longer (think 5-8 days or so) have no rush in getting the package to you.  Your package stays in shipping much longer, so there is a higher probability that other items may damage the package in transit.  Perhaps the airplane has packages on top of yours. 

I am not sure which way damages packages more, but I always think about it when I’m ordering something.  I know I will be thinking about it this holiday season.