Billy and Gene, the two brothers who are at the opposite ends of neutral behaviour; Billy the good, and Gene the bad (and somebody-somebody the ugly). Billy is the one with principles who thinks and makes fairly rational decisions most of the time, but Gene is the one who sees himself as being the queen bee and is therefore very ignorant of other people's feelings and opinions.
First of all, Gene is certainly the less favoured character of the two, for he has a bad record of actions and decisions throughout the story. For example, early in the story Billy mentions Gene's little incident with their father's new 1966 Chevy Impala, which was less of an incident, and more of a "totalling off" of a brand new vehicle . Another event that contributes to Gene's rating of total jerk is when he tries to rape Nancy Williams, his date, in the back seat of the car they were driving to the dance in, while she shouted things like "Gene! Well for chrissakes, relax!" trying to make him stop . Gene had no interest in hearing what she had to say (or scream) because of his selfish character, which allowed him the (selfish and ignorant) pleasure of analyzing Nancy's shapes and curves, even without her consent. Without knowing those facts and many more, people would and do confuse Gene for a human being.
In contrast to those events, Billy has a much cleaner record. Nobility is noticeable in this character when his brother refuses to go out and get the girls, but he comes through; "Oh, Christ" he says, "I"ll go get them, Gene. It's such a big deal." . He goes out into the blizzard and fetches the ladies in that freezing weather because that is the way it is done in a land where people with principles live, and Billy knows it because he is the one with principles in the story.
How can such ignorance interact with such principles? How can such good be related to such evil? Unison by blood is always very strong and in this case, inevitable.