Any person is like an onion -- you have to peel back the layers to find what is really underneath the exterior. Of course, unlike an onion, the layers are artificial where people are concerned. Those things which are used as yardsticks and signposts as to who or what you are, are hung there by others, and, sadly, we tend to believe them after a time when they have been used repeatedly to describe us. We look in the mirror and see only the layers, and not what lies beneath.
When society does this, it is only with the intent to ensure that we can differentiate "us" from "them": the famous from the average, the beautiful from the plain, the lithe from the heavy, the light from the dark. Society divides people up finely, into smaller and smaller gradations, as if trying to fit people to some Dewey Decimal System of humanity, as if attributes tell the whole story of what a person is and what they represent to the whole. When you can apply a name or a tag or an epithet to another, you can keep them at bay, avoid having to treat them as a human being with feelings, emotions, and, above all, value.
We catalog many things: stars in the sky, elementary particles of matter, the animals and plants of the kingdoms of life. No matter what something is or how we divide it, that thing is still intrinsically one thing. White dwarf or red super-giant, they are all stars; barracuda, earthworm, hibiscus, or rabbit, they are all life. A catalog may help us describe the variety of things, but it does not, should not, reduce those things to their descriptors. The fiery heart of any star is undergoing the same processes as any other, variant only in the type and amount of fuel being consumed to generate the radiation that streams away into naked space. It cannot be said that Aldebaran is better than the Sun is better than Betelgeuse... they are all stars, filling their role in their great variety. To say one is better than another is to make a value judgment that the universe itself does not make.
While it may seem hyperbolic to compare the variety of humans to the gaseous furnaces that are stars, it is no less apt. People are what they are, based on factors malleable and static, from the environment in which they survive to the genetic material handed to them down the generations. We may need to differentiate them for purposes of identification, but beyond that, when we take those differentiations and apply them as traits, this leads to discrimination. There is no reason to believe that the things that people do as part of society are simply because of "how they are." For the labels we apply go from being merely labels to internalized feelings of worth or worthlessness, as if society is the ultimate arbiter of who we are, and we have no business straying out of our assigned group.
Truly, if we are to divide human society based on any measure, then the one that best fits is a person's level of concern for their fellow human beings. For we can differentiate people easily enough by the care and compassion they show for others, either before our eyes or through their good works. The dividing line, if it can be said there is one, is between those who, even in the slightest, identify with the plight of their fellow humans, and those who wish to separate themselves from humanity, insulating themselves from the mass of Mankind, content in their own fortune, and unable to empathize with any who do not meet their standards.
And even there, that line must of needs become indistinct, for while we might revile those who would look down upon us, they, too, are human and deserving of sympathy, compassion, and empathy, even more so, given that they cannot find it within their hearts to reciprocate.
We must bring down the barriers between us; they serve no purpose save division, and as was so aptly put by Abraham Lincoln: "A house divided against itself cannot stand." We, as a species, will surely fail if we cannot learn to cast aside those things that chain us to a primitive past, for we face an uncertain future, whose course remains uncharted, but cannot be navigated without each of us doing our part. To survive, we will have to do this -- to continue in our current course, only leads to peril and eventual extinction.