Good article. I liked the artwork at the top too!
As usual, scientific investigation of tickling produces ambiguous results. E.g., the link to humour is there and not there: I laugh easily in humorous situations, and watch a lot of comedy with great pleasure, and I am also very ticklish. Yet is there a link? I have always found being tickled a far from funny or pleasurable experience, rather like the author of the article, and MRI scans apparently show that it is indeed not analogous.