The Beauty of Brutal Honesty

Urban Dictionary defines "brutal honesty" as follows:
(1)Tactless, hurtful, candid openness completely disregarding another’s feelings, hopes, dreams, or desires.
(2)What guys use to get you to look over the fact that they're being total and complete assholes

While I'm smiling on the inside, these two definitions are very thinly based in fact. There is however, some truth in the above definitions. 

Why do people (myself included) present as brutally honest? What is the gene or DNA strand that makes certain people this way?

It has been suggested that one way that people, such as myself, become brutally honest is that they had hypercritical parents. When submitting a piece of artwork in grade school, instead of being praised for the attempt, the art is picked apart and overly-criticized for its obvious flaws.
This does not fit my upbringing.

A second theory is that "overtly" honest individuals use their honesty as an offensive weapon or a defense mechanism to deflect from their own shortcomings. While I have known individuals who use their honesty this way, it still does not apply to me personally. Although I do have many shortcomings.

Thirdly, it has been stated that those of us who are brutally honest have no social filter or lack tact. This fits me. 
While I don't consider myself socially awkward, I fully recognize the fact that I have little tact when dealing with people on a day-to-day basis. This trait was simply never fully developed in me as I was always told to "be honest". I understood this to mean that honesty superseded any social protocol; such as telling a woman that what she has on makes her look like she's for rent.  

I have always found that forthrightness cuts through most of the red tape used to cover and hide one's own insecurities. In fact, in my experience, I have found that the majority of people prefer brutal honesty to tap-dancing around uncomfortable issues and situations.
Here's a large difference to my take on it......I typically do not actively seek out people to offend. If asked my opinion, I will give it; and it will lack a definite amount of sugar.

If you are afraid of the answer you might get, don't ask the question.......:)