Some people go to extraordinary lengths to be difficult. Think of the diva actress whose on-set needs can never be met or the boss who keeps moving the goal posts. The difficult person elevates the deliberate provocation to an art form. The underlying message is often, "Unless you agree with me and go along, you'll regret it."

One clue that a person is attempting to intimidate or manipulate you is the use of unpredictable, or protean, behavior—acts that are random and seemingly out of the blue. A dictator keeps his minions guessing—and scared. Some forms of despotism are much subtler: Duke Ellington was known for provoking heated rivalries and feuds among his bandmates in the belief that such strife would make the music hotter.

Erratic behavior is a powerful weapon because it defies accurate prediction. Often, the behavior comes as a surprise even to the person generating it.

Flying into a or staring you down and dismissing you summarily are common strategies to keep you off-kilter. Unpredictable actions serve the purpose of confusing potential usurpers and avoiding responsibility. Your boss freaks out, throws things and yells. Some might call him irrational. But the irrationality gives him a leg up.

Erratic behavior served adaptive ends in our past, and it still does. Just as a minnow might cut a zigzagging path to avoid being snapped up by a larger fish, the boss alternately screams and stonewalls to avoid having her motives laid bare.

Protean behavior evolved to prevent people from being psyched out. That's not to say that fickle acts are always openly hostile and aggressive. The difficult person can just as easily be solicitous or seductive: Think of femme fatales from biblical Judith to Mata Hari. Unpredictable behavior is at heart about , and it's just as likely to be as conscious.

If such behavior comes from a boss or a spouse, you've got some tricky choices to make. There are several problems confronting you at once, since you're juggling competing . Your ego tells you to stick up for yourself, but you want to avoid an unnecessary argument.

Usually we can't resist getting riled up in our own defense. The ease with which we fall into dueling dyads is a remnant of a "culture of honor" that most of our ancestors needed to adopt. Our circuitry equips us to immediately jump to our own defense. The Neanderthink urge to rectify an injustice kicks in automatically, lest we accept abject defeat. The immediacy of the "me versus you" and "us versus them" reaction hinders a more intelligent and considered response.

We usually regret having charged into battle—or at least we wonder what we were thinking. And that's just it: We weren't thinking. An emotional reaction bypasses thoughtful deliberation. No rational person today would engage in an argument with a random person on the street. But if someone bumps into us, blocks our way or otherwise wants to hassle us, our immediate inclination is to freeze, fight or flee. Similarly, our immediate response to the verbal slights or manipulative barbs of a difficult person is often to fight back. Your immediate reaction is, "I can't stand this crazy, insulting behavior."

We too quickly jump to our own defense when we feel insulted. We do so because we have evolved a hypervigilant concern for our standing among peers. This focus on status makes sense as a play for dominance and power, qualities that translate into real options. The need to retain status is an example of Neanderthink. This knee-jerk demand for status can push us to get outraged and to lose focus on larger goals, such as keeping your job or your mate. We want to prove that we are correct—but doing it angrily and intolerantly can hinder your major objectives. Dominance at every turn is good, but not a necessity.

Still, we're so captivated by displays of dominance that we pay boxers millions of dollars to watch them square off and even pay to see professional wrestlers play-act a power struggle.

This is not to say that everyone has the immediate urge to lash out in self-defense. Some people freeze when confronted with criticism, telling themselves, "I must not be criticized" or "I must be above criticism." Temporary paralysis in response to a physical threat may once have kept you alive; but freezing in the face of a verbal onslaught won't help you make your case.

To cope with a difficult person, you need to learn to question your automatic defensive philosophies, such as "I will not be treated that way; I won't let you get away with this" and "My reputation is on the line if I fail."

Resisting the trap set by difficult people is easier if you're aware of your vulnerability to getting hurt and then feeling angry. That tendency is a vestige of Neanderthink, because there was a time when your status was more closely linked to life or death than it is today.

Better to check your fight, flight or freeze reactions and refuse to be a part of a duel in which you're an inadvertent participant. Sure, you need to stand up for yourself, but do so without demanding that you be above criticism at all costs. Remind yourself of your long-range goals: saving time, energy, hassle and maybe even your own hide.

Staying Rational When Confronting the Difficult Person