So why do people so readily recognize differences amongst those around them? I came to realize a few points that could be made about this. One way that this could be advantageous is the idea of genetic genetic altruism. Another reason for this recognition of differences could be that it is how we define ourselves. Lastly I think noticing differences amongst those we view is a way for us to take initial stock of an individuals strengths and weaknesses.
First off, I must give my wife credit for teaching me much in the way of biological reasoning. This is the idea that our biological needs have shaped us as a species into the habits and forms we now possess. By genetic altruism I am referring to a persons interest in benefiting those of similar genetics then those of more differing genetics. As humans we tend to be very superficial when it comes to racial ambiguity. Unfortunately, this means that often times we show more interest in benefiting those that look and act more like us then we do in benefiting those who are more genetically like us. An example of this could be that we would socialize and group ourselves with people who share the same skin color and religious preference as opposed to putting energy forth to benefit a distant relative who happens to have a different skin color. However more often then not a person that looks and acts similar to us is going to share portions of our genetic makeup and by helping that person we are in some way continuing our line through them. My wife told me a story about closely related apes that will take care of their siblings young as a mechanism to continue the genetic line. the theory behind this idea is contained here http://www.genetics.org/cgi/content/full/176/3/1375?maxtoshow=&HITS=20&hits=20&RESULTFORMAT=&searchid=1&FIRSTINDEX=0&displaysectionid=Perspectives&resourcetype=HWCIT It is quite a bit of reading but it does explain what I am trying to say here clearer then I am capable of.
The second reason that we recognize the differences between people so readily could be that as individuals differences are how we define ourselves. No two people look and act exactly the same. This is because all humans are individuals. We all look, think, and behave differently. This difference is the way that humans express their individuality amongst the groups they belong to. Last night my wife and her friend watched the movie "Pretty in Pink". this movie is set in the 80's and it portrays a very socially segregated high school where, for social reasons, the "Mutants" are not allowed to mingle with the "Richies". In this movie the mutants find very extravagant and varied ways of altering their physical appearance in an attempt to stand out in some way. However this leads the richies to view them as different and to completely shun them.
Finally, the first time you meet a person you always make an initial judgement of them. Sometimes this is a physical inspection and some light conversation. Or, other times there is no conversation and you make a judgement of a person on a purely physical appearance basis. Either way you come away from the exchange with an initial impression of that persons strengths and weaknesses. In the past this was a very important survival instinct. Waiting to get to know the animal that is about to devour you is not a luxury that our species has always enjoyed. Those who were able to quickly gauge an adversary's strengths and weaknesses were often the ones that saw the sun rise the next day and were able to continue their genetic line. However those that could not make snap judgements of another creature were not so fortunate.
So, the point of this post is not to say weather discrimination is right or wrong but to hypothesize on some possible reasons why we as humans are so quick to judge another person as different. To act on this judgement in a modern society is a completely different discussion.
I am truly sorry this rant ended up being so long. Sometimes when you get into a groove you just have to roll with it. Please feel free to let me know in what ways my ideas and observations differ from yours. I am always interested in integrating another persons perspective into my own to make my views more refined.