Clarified and narrowed down as requested!
The following guidelines have already been established for the world. These are presented so you get an idea of the people we are dealing with:
1. The members of this society are humans who evolved from social sapian creatures, just like us.
2. Total human population is about 2-3 million people total. These are grouped together in villages or hamlets of up to 1500 people. These villages are permanent settlements. No more than 3-5 days of travel separates each village.
3. The planet they live on is Earth-like, but with an extra cold climate. There are 4 seasons just like parts of our world, but milder. Temperatures range from 45-65 degrees Fahrenheit (7-18 °C) in summer to as low as negative 70 (−57 °C) in winter. Precipitation is moderate year-round. Plants and animals adapted to survive in these conditions are the same as those on our Earth that can live in these conditions (think north-american or siberian).
4. Villages are centered around agriculture, with the humans devoting their energy in the "warm months" to growing and stocking food. Food is hardy, cold-resistant stuff like cabbage, carrots, chives, radishes, etc. Sheep and goats are the domesticated animals of choice, providing wool, milk, and meat to keep them fed and clothed through the winter. Wild game is hunted only for fur, creatures like buffalo, rabbits, elk, etc.
5. Though each village has certain unique cultural traditions depending on their location, history, etc, the human culture as a whole is the same. They are united and do not war against one another. Trade and communication have been well-established, as well as a basic "global" economy.
6. Technology-wise we are looking at roughly Bronze Age. Mostly spears or bows & arrows for weapons. Armor is rare because the thick layers of fur commonly worn by people to keep warm provides sufficient protection against attack. Metal is used for plows, pots, and tools, not warfare.
7. Medicine however, is very advanced, and lifespans are close to current First World levels (70 years or so), due to an over-abundance of healing herbs. This planet happens to have an impressive list of hardy, cold-resistant herbs. Natural birth-control, blood coagulation, natural antibiotics, congestion, allergies, bowel irritation, etc. These herbs are documented and cultivated by specialized farmers. Now surgery, setting bones, and other physical hands-on remedies would still be incredibly dangerous, but at the very least they can provide herbs to numb the pain and to stave off infection.
The guidelines above are firmly established for this world and not part of the question, just meant to help out. The following three concepts are the concepts of "marriage" or domestic partnership that I am considering for this society as a whole.
A. Partnerships are temporary and flexible. Men & women are both in control of the "transaction" so to speak. Men and women will court and flirt with whatever partner they like. The partnership can last for a single night, or several months, but longer than that is considered weird or even taboo, and under no circumstances do they move in together. Because birth-control is available, each woman gets to decide when and with whom they will have a child, with each woman being "expected" by societal pressure to have at least ONE baby, most having multiple. Men are not involved in the raising of their biological offspring. Instead, each household consists of brothers and sisters, the children of the sisters, and the grandchildren of those daughters. Men remain in their mother's households for life, and are responsible for helping to raise their nieces and nephews. In this way, men can always be assured they are caring for their own blood and helping the next generation to grow up protected, and women can always be assured they are never raising children alone without financial support.
B. Marriage is between two men and one woman. Each woman would marry two eligible men. Whether they have a choice in the matter, or if this is an arranged marriage doesn't really matter, but let's assume the initial partnership is amicable to all three. The woman would have sex with both men, but not have sex outside of her marriage, same for the men. Any children born of the arrangement could be either husband's child. Therefore, each husband is supposed to assume the baby is theirs, and care for their wife and child(ren) cooperatively with the other husband. In this way, a woman would always have two men working to put food on the table, and if one of them should grow sick or be killed somehow, she and her children are not left bereft and without someone who can provide for them.
C. Men and women are kept separate from one another and no formal partnership exists. There are no "family" households, but rather large dormitories where men and women sleep. Village work is assigned to each gender and men and women are kept separate for most of the day. Meals, meetings, village discussions, etc take place in a large communal building or setting, this being the only time that the genders intermingle. Men and women are free to choose whatever sexual partners they please. Sex in general is seen as an optional and enjoyable activity, not something for the purpose of reproduction. Pregnancies would be by choice, or perhaps would be "assigned" to each woman upon reaching her fertile age. Infants are taken care of by the women, but as soon as they are weaned they are split up by gender. The whole gender is then responsible for rearing "their" children and mothers and fathers are out of the picture. The "takes a village" model applies here, with every woman being responsible for the raising and disciplining of girls, and every man raising and disciplining boys. ____________________________________________________________
How would society as a whole view sex, sexuality, and gender identity in each scenario? I.E. how open are people with sex and their bodies, how would society react to or treat homosexual relationships, would there be openly transgender or transsexual individuals, how could they be viewed by others?