I am going to answer your so called hypothesis in this ping
http://www.network54.com/Forum/204096/thread/1255888075/last-1255888075/Gikuyu%2C+Mumbi+and+Nine+daughters. with a brief social and spiritual History of the Kikuyus. What you do with it is your choice.
"In the beginning Ngai, who is the God and the divider or the universe, called Gikuyu the father of the tribe. Ngai gave Gikuyu a share of his land with rivers, valleys, forests rich with fruits and animals of all types. Then Ngai went to stay on Kirinyaga. ---. Then Ngai said: 'You will at times be in need of my help, when the time arises, slaughter a goat for sacrifice, then raise your hands towards Kirinyaga and Ngai or Kirinyaga and Gikuyu will come to your help.' (Rose Mwangi, Kikuyu folk tales: their nature and value 1970, 1983, Kenya literature bureau.
According to Kikuyu legend, in the beginning God created a man called Gikuyu and took him to the top of Kirinyanga (current Mt Kenya) and showed him all the surrounding land and bestowed it to him commanding him to establish his home there. God then provided Gikuyu with a wife by the name of Mumbi and they had nine daughters, from which the 9 principal Kikuyu clans namely; Achera, Agachiku, Airimu, Ambui, Angare, Anajiru, Angui, Aithaga and Aitherandu originated from.
Almost all Kikuyu women have their name emanating from one of these clan names. Legend has it that when the daughters were of age for marriage, Gikuyu offered a sacrifice to God under a fig tree (sacred to the Kikuyus) and God provided husbands for the nine daughters.
The Kikuyus base their organization on the family unity (nyumba). Several families are combined to form a homestead (Mucii) which is part of a sub-group (Mbari). The sub-group makes up nine clans (muhiriga). A tenth clan is sometimes added but only nine are counted because it is supposed to bring bad luck to count people, children or livestock.
Before a young man (mwanake) could become a warrior he had to undergo the rite of passage. A warrior would eventually graduate to the council of elders (kiama) of which a few composed the secret council (njama). The council was responsible for settling disputes. Disputes that the council could not resolve were determined by the ordeal of the hot knife. The extent of the blistering on the tongue determined guilt or innocence. Alternatively the culprits would take an oath on the githahi stone.
The Kikuyu man is known as Muthuri, meaning someone who can choose or discern evil from good and the woman is called Mutumia which means someone who retains family secrets and practices. Traditionally the Kikuyu society was polygamous, but this practice is no longer practiced due to their adopted Christian faith and for economic reasons. A man could only take a second wife in consultation with his wife and only if he could effectively provide for both of them.
The Kikuyus also practiced surrogate parenting where if a woman was barren, she could marry another woman to have children for her with her husband but the children would be considered hers. The surrogate mother would remain in the homestead but she would be subject to the woman not the husband. This similar to what the Hebrews practiced in the Old Testament.
The family lived in a homestead (mucii) with several huts for different members. The huts were constructed in a way that during the cold season the interior would be very hot wile in the hot season the hut would be cold. The husbands hut was called thingira and this is where he gave instructions and taught his children on family norms and traditions. History was passed on orally from generation to generation through teaching by parents using proverbs, and by folklore.
The husband also discussed serious family issues with his wives in his thingira. Each wife had her own hut where her children and her slept. After the boys went through the rite of passage ceremony, they moved out of their mothers hut into the young mens hut. The Kikuyus had a systematic method of family planning. A father would only have another child with his wife after the youngest child was at an age where the mother could send him to look after the familys herds or goats.
The Kikuyu practice a rite of passage for boys at around age 13-16, which involves them going through a circumcision ceremony and being taught by older men what it means to be a man, and subsequently being ushered in to manhood. Traditionally, the rite of passage involved boys of the same age groups participating in the event. The group would be named after an important event happening at the time of their passage. For example there is an age group associated with syphilis (gatego) because it happened when the Europeans are alleged to have brought syphilis to the Kikuyus.
Traditionally, girls went through a similar ceremony and had older women teaching them what it meant to be a woman as well as ushering them into womanhood. They also went through a circumcision ceremony. One of the things that was lost and has had negative consequences is the rite of passage for girls. Due to the colonialist pressure to discard the practice of female circumcision, the Kikuyus eventually did away with the practice but with nothing to replace the rite of passage.
In the form of entertainment the Kikuyu young men and women could travel to isolated areas for dance and feasting. Discipline was however strictly enforced and no man was allowed to touch a lady sexually. The young men mingled and danced with the ladies who eventually became suitors.
The community protected the honor and purity of a girl and had rules that ensured that a girl was not sexually exploited by a man. The grandmother had a critical role of checking if any man had unwound the inner garment (muthuru) of the young ladies. The grandmother had the responsibility of tying the garment tightly and safely to protect against any form of promiscuity in young women. Women who engaged in sex or got pregnant before marriage could only be married as a second wife (gichokio). The man responsible for the pregnancy had to pay a penalty fine to the father of the girl.
Today, a woman who has a child outside wedlock is still viewed negatively even though there appears to be no sanction against the man. The responsibility on the woman is high, yet, unlike the male, the rite of passage is missing since the traditional one has not been replaced with something else at a communal level. Aunties are encouraged to step in to counsel young girls.
The Kikuyus are deeply spiritual people with great reverence for God. They had prophets and priests with similar roles as those in the Bible. It is said that one of the prophets by the name of Mugo Wa Kibiru prophesied of the coming of the Europeans long before they arrived in the coast of Kenya. It was said that there would come people from a different land having the color of the frog of the banana plantation something close to the color of the Caucasians. He also predicted the arrivals of airplanes which would be like butterflies in the sky.
They believed in blood sacrifice for atonement of sin and for thanksgiving. They prayed facing Mount Kenya because they believed God lived on the mountain. Men approached God not for personal needs but only on behalf of a social group. The whole tribe did this to avert a drought or an epidemic. The family would call on God on the four crises in human life; birth, initiation, marriage and death and only as a group affected by these events. The form of prayers used by elders at public gatherings beseeched God for wisdom, health, tranquility and the increase of the fields and flocks.
In his book, Facing Mt Kenya, Jomo Kenyatta, the 1st president of Kenya, a Kikuyu by tribe, writes concerning the worship of God by a certain sect of the Kikuyus in the 1900s,
"Their prayers are a mixture of Gikuyu religion and Christian; in these they add something entirely new to both religions. They perform their religious duties standing in a picturesque manner. In their prayer to Mwene-Nyaga (God) they hold up their arms to the sky facing Mount Kenya; and in this position they recite their prayers, and in doing so they imitate the cries of wild beasts of prey, such as lion and leopard, and at the same time they tremble violently. The trembling, they say, is the sign of the Holy Ghost, (Roho Motheru) entering in them. While thus possessed with the spirits, they are transformed from ordinary beings and are in communion with, Mwene-Nyaga (God).
From this Histroy I don't see any place for incest,sodomy or homosexuality. It is my submission that what we are witnessing is as a result of us abandoning our culture and adopting a culture that has lost its way. Where are the Kikuyu elders today to train the young men on what entails manhood? Where are the women?
We were a community which took care of one another but we have now adopted the selfish and individualitistic culture of the West and this is the consequence. We are cpmpeteing on who is more Westerenised than the other. God help us all.