Chalker, Rings of the Master series - has a change; brilliant rebellious woman was given a lush body, and more hormones/sex-drive (continuously pregnant?) - as a means of punishment/control, iirc.
She was the sort of woman men fantasized about: small but perfectly
proportioned, her face one of classical Han beauty, her gestures and
movements somehow always erotic. Her looks masked her extreme
intelligence: Her IQ off the measurable scale, and she was an authentic
genius whose mind worked so fast and on so many levels it often seemed
more computerlike than human. She was not without flaws; as the oldest
child of the chief administrator of the Han district, she was spoiled rotten,
and her intellectual and physical development had not been accompanied by
any real emotional growth; there she was almost childlike, a situation her
parents kept excusing because of her age, although she had just turned
For example, you have high hormonal levels, but your
psychosexual level is quite low, meaning that you don’t think of physical
sex as very important to you. Now, that energy has to go somewhere, so it
goes into aggression, a drive to work or achieve, that sort of thing. It’s all
interrelated, and it shows up quite clearly on my monitor here.
The psychochemistry was simple, less than child’s play to the masters of
Melchior. Eliminate the blockers, shift the hormones, create others that
would be manufactured ever after. She was not merely oriented back to
female, she was reoriented to very female. She would be like an animal in
heat, single-minded and insatiable, until a pregnancy occurred. No test
would be needed. Once the brain received notification and began the
preparatory processes, those animal urges would cease. She would be
normal, in full control, and since she would retain her old memories and
basic personality, and since she would find her animal self unnerving if not
somewhat frightening, it was predicted that during the whole period she
would probably prefer women as company, friends, and lovers. Once the
child was born, her body would begin a repair and reset, and when it was
prepared once more, in a month, perhaps two, the cycle would begin again.
It would continue this way until she ran out of eggs, perhaps thirty years
"Another guy, a kind of leader for some kind of rebel group, was turned into a woman with low IQ to keep him from continuing his rebel activity."
It's convoluted, but maybe OP is mis-remembering.
This character is originally female, takes on identity of one of two boys who were only remaining survivors of a tech-cult. Mind-print and superficial body changes (lower waist), to escape.
It took almost four hours to clear and secure the technologist cell. At the
end, forty-seven had been killed and almost twice that number wounded, but
all but two of the three hundred twenty-four technologists had been killed.
Those who were not killed in the defense committed suicide, taking their
families with them. The only two survivors were young boys who had been
felled in an explosion and had been presumed dead by their own
She selects logic-only mind-set:
The sense of strong sexual identity faded but was not replaced. She had no concept of maleness or femaleness; gender was an irrelevancy, without meaning to her. The anger, too, faded quickly, and she felt totally calm, unable even to relate to the emotions she had experienced up to that point. She was like a machine: aware, intelligent, but without passion, without any feelings at all about anything. Yet she was as clearheaded, as logical, as she could ever be.
Stripped of her animalism, she stared at the patterns in the hologram and
almost immediately grasped their logic and meaning based upon what she
had seen so far. At this level, where even pleasure and pain, fear and love,
were mere terms, she analyzed her situation. She was being reprogrammed,
but this level was the most efficient for undertaking an escape. There was no
hatred, no bitterness, no feeling of any sort that was relevant to her. Escape
was mandated because this stage was the optimum one for her potentials,
and it was illogical to abort it.
"I would like to perpetuate my current physical and mental orientation until
otherwise instructed. Then stand by until I am able to contact you here
She swaps for boy:
"The younger of the two is close to your size, and with preparation and in
transport clothing you might pass for him. While they will not look too
closely so long as the paperwork is correct, some extreme adjustments
would have to be made to you in order for you to sustain the masquerade all
the way to the spaceport. Additionally, something must be done with the one
whom you will replace, and adjustments must be made to the other, for he
will know immediately that you are not his cousin and is most likely to
I can make some basic physical and chemical alterations in you within
two hours. Because of the time involved, much of it will be synthetics and a
basic shell, but it will be authentic and convincing. It is not possible to
actually switch minds, nor desirable in this case in any event, because your
psychochemistry and physical requirements are so different, but I can lay his
template atop my alterations and reinforce the illusion with hypnotics. You
will act like him, think like him on the conscious level, walk and talk like
him. You will not be him, but you will think you are. I will then use a strong
hypnotic on the other and replace the mental image of Chu Li with what you
will look and sound like, and he will accept you as his cousin even in the
face of true physical evidence to the contrary.
She's put in cell with other boy:
"It is the same with me," Chu Li responded. In Han and many other Oriental
cultures, cousins of the same generation regarded one another as brothers
and sisters and acted accordingly. The two boys were close. "My head is
crowded and confused, almost as if . . . "
"As if what?"
As if there is another also inside my head, he thought, but he couldn’t say
that. "I just wonder if they messed with our minds, and if they did, would we
Memories of brutish guards beating and torturing for the slightest
infractions. Memories of one of them.
"There is no pain," Chu Li told his cousin. "It is not right, though. I shall
have to pee sitting down for a while, I think. I do not know what awaits us,
but it cannot be any worse than here. Even death is better than here."
Genitals are not correct for her mindprint/hypno as a boy:
"Only half a man," he responded, not realizing how much truth there was in
that description. Because she had told him her ultimate shame, he felt not
only that he could tell her his secret but that it might give her some idea that suffering was not exclusive. "The guards beat me terribly where that which makes me a man is, leaving it battered, bruised, and perhaps broken. There is no pain, but it will be a long time before I know. That is what I was too embarrassed and ashamed to say before."
The hypnotics held. When he emerged and looked at himself in the mirror,
he still saw the image of a young boy, not the image that was actually there.
He was led to the bathroom, and he sat, holding his head in his hands. Then
he looked down and put one of his hands down between his legs. Suddenly,
some of the conditioning broke away and was gone. They have emasculated
me! He unbuttoned his tunic and looked at and felt his chest. Two huge
nipples atop small, perfect breasts. He quickly got up and disrobed
completely, examining his body as if for the first time. The smooth skin, the
curves . . . A girl! They have changed me into a girl!
Other character mind-printed as ape to gain compliance (the low iq portion).
Lazlo Chen had indeed taught Hawks the true meaning of "primitive." He
had restored the two women, and after having them fully mindprint recorded
so they could be restored later, he had wiped them basically clean and
imprinted on them the mindprints of female apes of some kind.
Chen had ordered him imprinted with the bull ape imprint but otherwise left
alone. He knew, and he had to watch those he loved act as animals and react
to them so, as well. It was the most miserable, unhappy experience in his
However, very little horse-riding in that book, and none by altered people.
Quotations are partially out of order, to support points.