This brought to mind an article in my set of Britannica. Bear with me while I type in a few paragraphs; I'll get to the point afterward.
Humor and Wit
In all its many-splendoured varieties, humour can be simply defined as a type of stimulation that tends to elicit the laughter reflex. Spontaneous laughter is a motor reflex produced by the coordinated contraction of 15 facial muscles in a stereotyped pattern and accompanied by altered breathing. Electrical stimulation of the main lifting muscle of the upper lip, the zygomatic major, with currents of varying intensity produces facial expressions ranging from the faint smile through the broad grin to the contortions typical of explosive laughter.
[included the introductory paragraph simply because such a dry description of humor is humorous itself; at least I find it so]
...
Why tickling should produce laughter remained an enigma in all earlier theories of the comic. As Darwin was the first to point out, the innate response to tickling is squirming and straining to withdraw the tickled part -- a defense reaction designed to escape attacks on vulnerable areas such as the soles of the feet, armpits, belly, and flank. If a fly settles on the belly of a horse, it causes a ripple of muscle contractions across the skin -- the equivalent of squirming in the tickled child. But the horse does not laugh when tickled, and the child not always. The child will laugh only -- and this is the crux of the matter -- when it perceives tickling as a mock attack, a caress in mildly aggressive disguise. For the same reason, people laugh only when tickled by others, not when they tickle themselves.
Experiments at Yale University on babies under one year revealed the not very surprising fact that they laughed 15 times more often when tickled by their mothers than by strangers; and when tickled by strangers, they mostly cried. For the mock attack must be recognized as being only pretense, and with strangers one cannot be sure. Even with its own mother, there is an ever-so-slight feeling of uncertainty and apprehension, the expression of which will alternate with laughter in the baby's behaviour. It is precisely this element of tension between the tickles that is relieved in the laughter accompanying the squirm. The rule of the game is "let me be just a little frightened so that I can enjoy the relief."
Thus the tickler is impersonating an aggressor but is simultaneously known not to be one. This is probably the first situation in life that makes the infant live on two planes at once, a delectable foretaste of being tickled by the horror comic.
--- end of article citation ---
The thought patterns brought up by reading that would seem to be somewhat along the lines of what Frans was evidently experiencing by what he'd read. Maybe.
Anyway, one connection to the discussion I'd like to make is that we see young animals playing with their siblings all the time. They quite often engage in mock attacks with each other. They seem to enjoy such play for the most part. But it's not necessarily pure play -- if they were in the wild (and sometimes under our care anyway) this is good practice for them and a means of honing their survival skills.
Another connection is that while Joe Blow might well be able to tickle his German Shepherd's belly and make her wildly kick her hind leg when he finds that "sweet spot", I would most likely have a hard time even getting my hand near her belly unless maybe she knew me very well or he was also closely present and indicating to her by his body language that I was no threat to either of them.
To the possibility of animals having hope, it seemed to me on occasion that my little tomcat buddy (may he rest in peace) would show signs of hope as he waited patiently by the hole in the ground into which he'd chased Mr. Charles Monk.
That was a good exercise. I did quite well transcribing the article excerpt but did consistently mis-type "tickle" in all its forms. Weird.
