A community starts with your family. Many people have bad families and go on to form new families or join other communities.
Our belonging to society is conditional on our contribution. We are cared for, when we have downtime, because we contribute. Typically in most western societies, if you are unwell, the government ensures you get healthcare and can continue to survive when you cannot work.
Most western governments have this contract with their population, we need you and we will help you when you need help. Women need this contract because it is expensive to take off time from work when raising children. It is a detriment to her career yet she is expected to give birth and raise her children most often for free or with her husband's help in the US. Other countries will contribute to the women by helping her finance raising her children.
Her contributing children to the population aids in the long term success of the society. Children will grow up to replace older generations by doing the work, repairing the infrastructure of the society, producing the next generation of technology, and go on to produce the successive generations.
In light of our need for society, and we reap benefits from being part of that society, our society is a mechanism for sharing our skills, resources and time.
I help you, you help me.
We are also lazy creatures, our bodies like to conserve energy, so in the evenings when we come home from a hard day at work we turn on the TV and watch other human being interact with each other. This way we don't have to go to the trouble of interacting other other human beings and deal with the problems they have.
While we ask each other how the other is going, we mostly want to hear everyone is doing well and the day-to-day problems people have should be just background noise on our lives, not unless its major, then we'd probably like to be kept in the loop, but this is just for our acquaintances.
Real friends know about what is really happening in our lives. Real friends know your favorite colour, real friends probably even know what you ate for dinner. Real friends don't ostracize us on a whim and if they do, they are expected to explain why. If they don't it leads to people doubting there is real friendship to begin with.
Corporations leverage our desire to belong to sell us stuff. People pay a lot to belong to Apple world. I remember when the iPod came out, people were telling me how awesome their iPod was with its fancy price tag and having numerous faults. I had an MP3 player that never had a problem, held more songs than I ever played, was plug and play so I could also transport my PhD thesis, sundry files easily.
Other corporations have developed worlds too, Disney, Virgin, you buy the product so you feel like you belong.
Furthermore these worlds are yours forever to belong to until you choose not to anymore.
Our need to belong spills over into our tribalism. We form teams because this is how we survive. Do not underestimate the damage you do when community members are ostracized without explanation. Nor forget that you benefit more from society than the money you receive in exchange for your time, skills and resources. You get to survive because of it, something that money cannot buy.