This was not,in many ways, dissimilar from the spankings given by our lady teachers. In some ways the elements of a tender and caring correction were present with the ladies, whereas with the males it was not.
I think pulling our pants up and baring our bottom cheeks, was in some sense a reminder to us of our little boy status, and that we were not big enough not to have our bottoms bared and smacked. In as sense, I suppose, bringing us down to earth, and quashing any over-weening sense of our own importance.
It certainly worked if that was the intention.