are a part of our everyday life. Even if you're not a by or training, you've got to admit that there's something to be said for the idea that everyone engages in some form of at least some of the time. The question is—can you detect the form of deception that you, your friends, colleagues, and family are using at any given moment?

We'll take a look at the nine most common defense mechanisms but first, let's set the record straight on two counts. First, it was a Freud, but not Sigmund, who defined the defense mechanisms. Anna Freud defined in detail the defense mechanisms sketched out by her father in her book, "The Ego and the Mechanisms of Defense."

Second, defense mechanisms aren't just an protective measure to prevent you from connecting with your ravenous instinctual desires. They also protect you from the of confronting your weaknesses and foibles. You can now add these two points to the 25 surprising facts about psychology I wrote about in an earlier post.

1. Denial. You can consider this the "generic" defense mechanism because it underlies many of the others. When you use denial, you simply refuse to accept the truth or reality of a fact or experience. "No, I'm just a social smoker," is a good example; similarly people can apply this to any bad habit they wish to distance themselves from including excessive or substance use, or gambling, and the like.

"Just say no," in this case means that you protect your by failing to acknowledge your own behavior. Denial may also be used by victims of trauma or disasters and may even be a beneficial initial protective response. In the long run, however, denial can prevent you from incorporating unpleasant information about yourself and your life and have potentially destructive consequences.

2. Repression. One step above denial in the generic classification scheme, repression involves simply forgetting something bad. You might forget an unpleasant experience, in the past, such as a car accident at which you were found to be at fault. You might also use repression when you "forget" to do something unpleasant such as seeing the dentist or meeting with an acquaintance you don't really like.

Repression, like denial, can be temporarily beneficial, particularly if you've forgotten something bad that happened to you. But as with denial, if you don't come to grips with the experience, it may come back to haunt you.

3. Regression. From repression to regression—one little " " makes all the difference. In regression, you revert back to a childlike emotional state in which your unconscious fears, anxieties, and general "angst" reappear.

In Freud's theory of "psychosexual" development, people develop through stages such as the oral, anal, and phallic so that by the time they're five or six, the basic structures of are laid down. However, every once in a while, a person either reverts back to a childlike state of development, particularly under conditions of . That road rage you see when drivers are stuck in traffic is a great example of regression. People may also show regression when they return to a child-like state of dependency. Retreating under the blankets when you've had a bad day is one possible instance.

The problem with regression is that you may regret letting your childish self show in a self-destructive way. Driving badly or refusing to talk to people who've made you feel bad, mad, or sad can eventually get you in worse trouble than what you had when you began.

4. Displacement. In displacement, you transfer your original feelings that would get you in trouble (usually ) away from the person who is the target of your rage to a more hapless and harmless victim. Here's the classic example: You've had a very unpleasant interaction with your boss or teacher, but you can't show your anger toward him or her. Instead, you come home and, so to speak, "kick the cat" (or dog). That's not very nice imagery, but you get the picture.

Any time you shift your true feelings from their original, anxiety-provoking, source to one you perceive as less likely to cause you harm, you're quite possibly using displacement. Unfortunately, displacement may protect you from being fired or failing a class, but it won't protect your hand if you decide to displace your anger from the true target to a window or wall.

5. . The first four defense mechanisms were relatively easy to understand. (I think.) Projection is more challenging. First, you have to start with the assumption that recognizing a particular quality in yourself would cause you psychic pain. Let's take a kind of silly example. For instance, you feel that an outfit you spent too much on looks really bad on you. Wearing this outfit, you walk into the room where your friends stare at you perhaps for a moment too long (in your opinion). They say nothing and do nothing that in reality could be construed as critical. However, your insecurity about the outfit (and distress at having paid too much for it) leads you to "project" your feelings onto your friends, and you blurt out "Why are you looking at me like that? Don't you like this outfit?"

In a less silly case, you might project your more general feelings of or insecurity onto friends—or worse—people who don't know and love you with all your projected flaws. Let's say you're worried that you're not really very smart. You make a dumb mistake that no one says anything about at all, and accuse others of saying that you're dumb, inferior, or just plain stupid. The point is that no one said anything that in reality could be construed as critical. You are "projecting" your insecurities onto others and in the process, alienating them (and probably looking somewhat foolish as well).

6. Reaction formation. Now we're getting into advanced defense mechanism territory. Most people have difficulty understanding reaction formation, but it's really quite straightforward. Let's say that you secretly harbor lustful feelings toward someone you should probably stay away from. You don't want to admit to these feelings, so you instead express the very opposite of those feelings. The object of your lust now becomes the object of your bitter hatred.

This defense mechanism could be subtitled the "lady doth protest too much," that wonderful quote from Hamlet. A less highbrow example is "Church Lady," the old Dana Carvey character from Saturday Night Live. Her secret obsession with became reversed into her extreme scorn for all things sexual. In short, reaction formation means expressing the opposite of your inner feelings in your outward behavior.

7. Intellectualization. You might also neutralize your feelings of anxiety, anger, or insecurity in a way that is less likely to lead to embarrassing moments than some of the above defense mechanisms. In intellectualization, you think away an emotion or reaction that you don't enjoy feeling.

For instance, rather than confront the intense distress and rejection you feel after your roommate suddenly decides to move out, you conduct a detailed financial analysis of how much you can afford to spend now that you're on your own. Although you aren't denying that the event occurred, you're not thinking about its emotional consequences.

8. Rationalization. When you rationalize something, you try to explain it away. As a defense mechanism, rationalization is somewhat like intellectualization, but it involves dealing with a piece of bad behavior on your part rather than converting a painful or negative emotion into a more neutral set of thoughts. People often use rationalization to shore up their insecurities or remorse after doing something they regret such as an "oops" moment. It's easier to blame someone else than to take the heat yourself, particularly if you would otherwise feel shame or .

For example, let's say you lose your temper in front of people you want to like and respect you. Now, to help make yourself feel better, you mentally attribute your outburst to a situation outside of your control and twist things so that you can blame someone else for provoking you.

9. Sublimation. We've just seen that people can use their emotions to fire up a cognitively-oriented response. Intellectualization tends to occur over the short run, but sublimation develops over a long period of time, perhaps even throughout the course of a person's . A classic example is that of a surgeon who takes hostile impulses and converts them into " " other people in a way that is perfectly acceptable in society.

This is perhaps putting things in terms that are too extreme. More realistically, sublimation occurs when people transform their conflicted emotions into productive outlets. They do say that psychologists are inherently nosy (not true!), but it's possible that people who go into human services fields to help others are trying to "pay forward" to compensate for difficulties they experienced in their early lives.

In short, defense mechanisms are one of the most common ways of coping with unpleasant emotions. Although Freud and many of his followers believed that we use them to combat sexual or aggressive feelings, defense mechanisms apply to a wide range of reactions from anxiety to insecurity.

Which defense mechanism is most adaptive? In general, the more "mature" defense mechanisms include intellectualization, sublimation, and rationalization. According to research by George Vaillant, people who use these defense mechanisms more often than others tend to experience better family relationships and work lives. You may never rid yourself of all your defense mechanisms, but at least you can grow from understanding what they can, and cannot, do for you.

Copyright 2011 Susan Krauss Whitbourne Ph.D.