Ever since I was a kid I have found interesting how it is possible to find a relation between any to objects. As many others, I had been following the news about the Higgs Boson. Cycling to my university, I was trying to sort out the new ideas of quantum physics that I have learned in this process. Not that I understand a lot of it but I remembered quantum physics still have problems to explain one of the most obvious forces that keeps the universe together and beautifully ordered, gravity.
Yes, Higgs Boson explains the universe not being just a disperse wave of energy with any structure. But this particle is a micro force unable to keep the earth going around the sun. So, they have several theories including gravitons. It is not that quantum theory is incompatible with gravity, there is just not a well proven theory but most of the scientists accept its existence.
So, there, culture. What keeps a culture together? Why do we recognize and feel different when are surrounded by the ones we considered members of our culture? The majority find this place just comfortable. A few express totally the opposite, a repulsive effect. There is good explanations of collaboration between individuals. There is also evidence of the strong cohesion between small groups, according, around 12 . “Furthermore, the maximum number of people with whom we can develop relations of trust regulated by face to face interaction and the presence of a mutually respected leader, during any time, is several hundred people”‘  And that is more or less the size of most of the companies in the world.
Then, we have countries but I will stop here because not sure what to say about cohesion of countries. We have very uniform ones, as the one in Nordic regions and we have Guatemala, for example. With 20 different languages and a bigger number of identities. Furthermore, a clear distrust on the government after the war in the 80s (considered genocide by many). If I were a governor, I would definitively would like to be in a country with a uniform culture. So, what is that force that keeps people together?
 Evans, Susan. Ancient Mexico and Central America. Third Edition. pp 27.