slave Branding in the Books

I have wondered upon occasion why brands are used on Gorean slaves. Surely Goreans have at their disposal means for indelibly but painlessly marking the human body. My conjecture, confirmed to some extent by the speculations of the Older Tarl, who had taught me the craft of arms in Ko-ro-ba years ago, is that the brand is used primarily, oddly enough, because of its reputed psychological effect.
In theory, if not in practice, when the girl finds herself branded like an animal, find her fair skin marked by the iron of a master, she cannot fail, somehow, in the deepest levels of her thought, to regard herself a something which is owned, as mere property, as something belonging to the brute who has put the burning iron to her thigh.
Most simply the brand is supposed to convince the girl that she is truly owned; it is supposed to make her feel owned. When the iron is pulled away and she knows the pain and degradation and smells the odor of her burned flesh, she is supposed to tell herself, understanding its full and terrible import, I AM HIS.
Actually I suppose the effect of the brand depends greatly on the girl. In many girls I would suppose the brand has little effect besides contribution to their shame, their misery and humiliation. With other girls it might well increase their intractability, their hostility. On the other hand, I have known of several cases in which a proud, insolent woman, even one of great intelligence, who resisted a master to the very touch of the iron, once branded became instantly a passionate and obedient Pleasure Slave.

2) Outlaw of Gor pgs: 189 | Chapter: 21

The thighs and the lower left abdomen are the brand sites recommended by Merchant Law. Masters, of course, may brand a girl wherever they please. She is theirs. Sometimes brands are placed on the left side of the neck, on the left calf, the interior of the left heel, and on the inside of the left forearm. The customary brand site, incidentally, is high on the left thigh. That is the site almost invariably utilized in marking Gorean kajirae.

14) Fighting Slave of Gor pgs: 349

"You're going to be branded," he said, "and put in a collar."
I reguarded him with disbelief.
"But so, too, will the other girls," he said. "You will all have your brands and collars."
I could not speak.
"Such things are prescribed by merchant law," he said.

22) Dancer of Gor pgs: 62 | Chapter: 4