As previously discussed, tickling is a strange phenomenon that I believe may have something to do with BDSM. Another Slate article:
Its importance begins in infancy. “When people say they hate being tickled and there’s no reason for it, they forget that it’s one of the first avenues of communication between mothers and babies,” he says. “You have the mother and baby engaged in this kind of primal, neurologically programmed interaction.” Or the father: I tickle my son; he shrieks; I tickle him more; he shrieks more; I tickle him yet more; he starts wailing. I apologize.
In a sense, this is our first conversation—how we manage to talk with someone despite being preverbal. The content here is socioemotional, and as a form of social binding, it preceded the development of language, Provine says.
New research suggests that many mammal species tickle (or can be tickled), including humans, chimpanzees, squirrels, elephants and even rats. There’s a back and forth to tickling play that suggests the back and forth of BDSM: figuring out the boundaries between pleasure and pain, between intimacy and invasion, between the self and the other. It’s a symbolic attack.
Being Canadian, I’m always interested in Canada’s contributions to the sexual edge of culture. I was delighted to stumble across the story of 
