Human beings exhibit a curious need to be able to identify others in such a way, that those others fit comfortably within a specific category. Scientists debate if the primary identification -- one that every infant makes when exposed to humans other than their mother -- make: is the other male or female? Because infants lack vocabularies that allow us adults insight into much beyond the moods and cravings of infants, no one really can say for certain if this is true instinct, or a learned behavior.

Even as we age, most people identify others' sex (male or female) automatically. Yet, when people see someone, say in a crowd in public, who is not easily identified as male or female, they will find themselves looking repeatedly at that individual, trying to determine which category they belong in.

As our culture has progressed, we are beginning to reach the point that traditional native (around the globe) were at, thousands of years ago: not everyone fits into those two categories in an exact, easily-defined manner. For we all are humans, a diverse group at that.

Still, we have some people who find it rather discomforting when others do not "fit" into one of the categories that they have filed in their minds. They have a limited number of files in which to place things ranging from gender roles, and things such as "race" and ethnic identity.

Hence, when we expand human behavior to include such things as "politics" and social structures, those with so few files in their heads have a compulsive need to "identify" others, especially those that they do not understand -- who thus create some level of discomfort -- and that is where we see the "name calling" in society, including DU, come into play.

Name-calling rarely is an accurate mode of identifying others; however, it always identifies the individual engaged in it as having limited mental capacities.