How to deal with a "difficult" person

In Diana McLain Smith's article Today's Trojan Horse, she explains how we can be part of the problem when dealing with so called "difficult" people:

...the idea that a person operates the same way—that is, badly—under all circumstances is quite simply wrong. In fact, cognitive psychologists call it the Fundamental Attribution Error: the tendency to attribute behavior to a person’s disposition instead of situational factors. True, some people are more difficult than others more often than others, but there’s always a good deal of variability within that person depending on the circumstance. That means it matters how you interact with a so-called difficult person: You’re part of the situation that’s influencing his or her behavior.

So what can you do?

...stop focusing so much on the other guy’s personality and start focusing more on the patterns of interaction the two of you create. The more you understand these patterns, the more you can avoid unwittingly reinforcing or escalating behavior you don’t like...