Introduction:In the natural world, from the very onset of its existence, life has been sustained through a constant battle of what biological arrangement or form can stick it through the challenge(s) that a given environment—which is ever-changing in our universe—throws its way. It's from this earthly-pervasive phenomenon, that the now common saying of "survival of the fittest" was coined, once the human mind was eventually able to pick it up [think for example, Darwin].
In a given environment, some biological units died out, and some managed to live on. In the biological world, this was made possible by what are—technically speaking—errors in DNA coding during the attempt at self-replication, i.e. another but crucial mode, by which life has been able to sustain and preserve itself to this point.
So, as it turns out, we humans and practically every other known life form owe our very existence to "imperfection" in the natural world. Without these "mistakes", it is safe to say that we would not be here. Yes, there are schools of thought which will argue otherwise and say that we owe our existence to a purposeful conscience, which has pre-programmed life to ride along the way it has, but that's another discussion [for related matter, see: link]. It's perhaps then natural to see why many multicellular organisms are competitive with one another, whether within or across species; why we see animals marking their territory for the attentive minds of those from both within and out of their own species, competing for a mate and for food. Humans are apparently no exception to this basic arrangement of existence: It's perhaps why humans would rather kill their own kind for natural resources than share, and for the purpose of the present entry, why we have so many more competitive or antagonizing social events than consolidating or unifying social events.