This comes near the end of "Beyond This Horizon" by Robert Heinlein. I can't find a link to post.
On a similar occasion but much later an event occurred which was quite as disturbing, but a little more
productive. Felix and the boy had been splashing in the surf, until they were quite tired. At least Felix
was, which made a majority with only one dissent. They lay down on the sand and let the sun dry them.
Presently the salt drying on the skin made them itch, as it has a habit of doing.
Felix scratched Theobald between the shoulder blades- that awkward spot-and reflected to himself how
catlike the child was in many ways, even to the sybaritic way in which he accepted this small sensuous
pleasure. Just now it suited him to be petted; a moment later he might be as haughty and distant as a
Persian tom. Or he might decide to cuddle.
Then Felix lay on his stomach, Theobald straddled his back and returned the favor. Felix was beginning
to feel rather catlike himself-it felt so good!-when he began to be aware of a curious and almost
When one human monkey does another the great service of scratching him, delightful as it is, it never
quite hits the spot. With infuriating obtuseness, despite the most careful coaching, the scratcher will
scratch just above, just below, all around the right spot, but never, never, never quite on it, until, in sheer
frustration, the scratchee will nearly dislocate his shoulder going after it for himself.
Felix was giving Theobald no instructions; in fact, he was nearly falling asleep under the warm relaxing
ecstasy of his son's ministrations, when he suddenly snapped to attention.
Theobald was scratching where Felix itched.
The exact spot. An area of sensation had only to show up for him to pounce on it and scratch it out of