The author writes, "Americans hug friends of the opposite sex, but during this hug only their shoulders touch, and participants end by rubbing each other’s back

The author writes, "Americans hug friends of the opposite sex, but during this hug only their shoulders touch, and participants end by rubbing each other’s backs as proof that the hug was nonsexual." This is so true. There are 3 types of hugs: the sideways hug (as the author mentions), the "A" hug where just the tops of the bodies meet, and the full on bear hug. If you get an "A" hug after a date, that's not a good sign. ;-)