In a completely uncivilized society, the weakest males would have been killed off before they could reproduce. Male aggression would have been similar to other mammals where only the strongest men and the best hunters were allowed to SURVIVE let alone reproduce.
Yet even in ape and monkey cultures, the omega males survive by emulating the behavior of females. They help with the children, they act subservient, and they REPRODUCE by having sex with a female while the alpha males are fighting it out.
India has had Hajiri, boys who become women, often running away from home to join the Hijri before they go through puberty.
In many cultures, those who voluntarily had themselves castrated were considered mystical, magical, and wise. Many of the Oracles in various cultures may have been castrati, transgender people who had themselves castrated. Much easier to guard the virginity if she is incapable of having vaginal sex.
The magical and mystical characteristics may have happened because they would help the women gather food and plants, learning which would be good and safe to eat, and which could make you sick, and which could kill you. With such knowledge, it would be easy to put a bully in his place by making him deathly ill with tainted food prepared by others, then to "Cure" him, because only you know the antidote.
On the flip side, alpha males, in civilized societies, often were quick to go to war. They could fight and kill each other, and the result would be a shortage of alpha males. Even beta males would be killed because they were less able to fight in wars. This would result in a few alpha males and many omega males who were clearly unfit to fight in a war.
Given 20-30 thousand years of this kind of evolution, the omega males would reproduce more often, with their sons being even more feminine. The violent and aggressive alpha male would be considered a criminal. United States prisons are full of alpha males who could not control their aggression and their anger.
Even the hormone therapy was possible. For many years, transgender women used to take a medication called Premarin, which actually stand for PREgnant MARe urINe. Castrati who wanted to grow breasts and live in a harem, usually as servants, would drink the urine of pregnant animals to enable themselves to grow breasts, because it was extremely high in estrogen. This may also have been used to prevent pregnancies - the earliest version of what we now know as birth control pills.
We know that there are genetic conditions such as XXY chromosomes, Androgen Insensitivity Syndrome, and a few other genetic disorders that can produce an omega male, which would most likely prefer life among the girls to life among the boys.
In addition, modern medicine has also been a contributing factor. From the early 1950s until the early 1980s, many women who were at risk of miscarriages were given an extremely strong dose of estrogen known as DES. The medication flooded the mother's bloodstream with estrogen which got passed on to the baby. If the baby was a girl, no problem, except a higher risk of breast cancer, uterine cancer, and ovarian cancer. If the baby was a boy, the body would be so flooded with estrogen that the baby would form not only a female brain, but a female skeletal structure. Many transgender women had the biological characteristics of women even though they had male reproductive organs.
Transgender Girl Biology
The male reproductive organs are formed late in the pregnancy, and many of those with any of the biological indicators have smaller than normal penis and the testicles are still up inside, sometimes not even in the inguinal canal. in some cases, the doctors may not even know, without an MRI or CAT scan whether the reproductive organs are ovaries or testes.
The shocking part is that there are about 100 different forms of "gender ambiguity" with almost as many different causes, often a combination of factors. As many as 1 in 15 males may have been born with some version of gender ambiguity.
The biological brain of a transgender woman very similar to the brains of MOST cisgender women. They have a smaller limbic system, which means they are more calm, more observant, less inclined to fight, less violent, and less competitive.
This can be a big problem for a transgender girl who is still living as a boy. Because they don't fight back, they are often the target of ALL of the other boys in a group. The alpha considers him an easy target, someone who can be easily intimidated. The beta male considers him an easy way to gain rank within the male hierarchy. As a result, as omega males, they are often violently attacked on a very regular basis.
If it's just slapping or taking a toy, it's not a big deal, but often the damage is far more severe. Ruptured spleen, damaged kidneys, damage to liver, intestines, and other vital organs are entirely possible. Examine school records and you will often find that transgender girls living as boys have been to the nurse's office, doctor's office, and hospital far more than normal. Often they are sick more often and for longer periods as well.
Most transgender girls living as boys don't tell their parents or teachers or other authorities anything about the attacks. The other boys make it quite clear that any attempt to report them will result in even worse violence. Furthermore, because the attacks usually involve a large number of boys, many of whom have influential parents, the school authorities can do very little to prevent such attacks or to prosecute the group of violent criminals.
Transgender girls living as boys often prefer the company of other girls whenever possible. They prefer the games the girls play, and often act like girls even though they appear to be boys.
ALL of this is biological, not social. The irony is that trying to make the transgender girl look more like a boy, by shaving his head, putting him in over-sized pants and flannel shirts, just makes the problem worse.
During this pre-transition phase, which can last anywhere from a couple of years to several decades, transgender girls become very isolated. Parents often don't like that their daughters are playing with a boy, the girls often "close ranks" and exclude transgender girls who appear to be boys.
The result is that transgender girls become very perceptive. They are keenly aware of what boys do (they hate it but have to participate due to social pressures) and what girls do (they love it but are usually forbidden), and they struggle to understand this strange world that treats them like a boy.
When a child in 3 or 4 years old, she might say "I'm a GIRL", but if adults try to correct them, to humiliate them, or to punish them, they may change this to "I wish I was a girl", wishing on stars, wishing on birthday cakes, wishing for Christmas, going to church and praying, yet publicly saying "I want to be a girl"
With enough negative reinforcement, they will stop talking altogether. They may even appear slightly autistic, avoiding people, avoiding eye contact, reading intensely, writing, music, computers, technology, a variety of hobbies, sciences, and so on. They may even become a bit like Sheldon Cooper on Big Bang Theory, intellectual and full of factoids, so they can keep people from finding out the secret they are forced to keep.
Often, as puberty starts, a transgender girl who has been repressed will become self destructive. They may try to castrate themselves, they may start drinking and drugging, often to the point of overdose. Only their closest few friends will realize how close they come to killing themselves or having someone else kill them. Police investigations of teen suicides suggest that more than half are gay boys or transgender girls who have been bullied and harassed.
To a transgender girl, the prospect of growing hair all over, of a deep voice, of erections and ejaculations, is a nightmare, a fate worse than death, because it could mean spending the next 50 to 60 years in the horrible isolation they have already experienced.
The more severe the dysphoria, and the more repressed, the higher the risk of suicide. A transgender girl who secretly would castrate herself, living in a Fundamentalist Christian home where there is zero tolerance for any LGBT issues, has nearly a 100% chance of being dead before their 30th birthday.
Those who do find support, even if only from a spouse or one parent, have a better chance. Often, a mother will encourage the feminine expression in socially acceptable ways, doing housework, helping with shopping, and encouraging socialization through music, theater, dance, and other non-threatening environments.
The transgender woman living as a man is more likely to suffer from obesity, alcoholism, heart conditions, stroke, and cancer, because he is living in constant stress.
Transition can reverse many of these issues. Once they are perceived as being girls, they will tend to be happier, more socially interactive, they listen more, they laugh more, they care about their bodies, so they may exercise more and eat a healthier diet . I've seen 60 year old men transition and literally get younger and younger, medically as well as physical appearance.