A pattern is a subtle manifestation of an inner state. Pop psychology tends to focus on behavior and that makes sense, but when you're dealing with an Enneagram pattern, don't be misled by one dramatic behavior.
A pattern begins with perception. I have a favorite device in some situations. I tell a story and ask people to tell me the story back. I know the story thoroughly so I notice what they leave out and what they emphasize. Sometimes that tells me a perceptual pattern. When they're talking about "just a story," the student or client isn't focused on some important reality (like hunger or they're late). So what they forget here can be what they forget all the time.
Each Enneagram style is held in place by some polarizations. Polarization is being acted out on national TV every day: The left and the right hold rigid, exclusive positions on most issues: immigration, the Iraq occupation, taxes - the list can be extended. Within individuals we take an issue or problem and break it into two incompatible extremes. For instance, I may not own a gun because I don't believe in murder. I abstain from all alcohol because I don't want to be an alcoholic. I don't try to be friends with him because nobody likes me. I coach a number of sales people who don't make any phone calls because they have too many to make if they're going to reach their quota.
Our Enneagram style often is shaped by an idealized self-image. Each style deals with it differently, but it usually functions as a substitute for real spirituality. I may consider myself liberal or conservative. If you ask me what that means, you will get all good qualities for my position and all bad qualities for the other one. If I am conservative, I am moral, responsible, patriotic and God-fearing. That may leave out certain balancing attributes that put me in jail intermittently. The dynamic works for liberals, too.
One Enneagram pattern is a narrative that we tell ourselves. We only do the things that fit our storyline. I have to be in favor of people carrying guns, because I am a cowboy bringing truth and justice to the world. Cowboys need guns for lots of reasons, and those reasons keep happening to me. "That's the story of my life," he says, as he is fixing a tire on his truck (in downtown Chicago).
The strongest desire in every Enneagram style is the desire to be right. People fly airplanes into towers, poison themselves with Botox, wear high heels or work 70 hours a week because they are convinced it is the right thing to do. People will argue over the relative merits of a car or candidate for hours more to prove they are right than anything else. The desire to be right is central to every Enneagram pattern.