http://personalityspirituality.net/articles/the-michael-teachings/chief-features/self-deprecation/

Self-deprecation means belittling yourself, or running yourself down, both internally and in the eyes of others. It is a drive to make yourself small or even invisible.
Self-deprecation is defined as:

• The disparagement of one’s own abilities; [1]
• Communication that expresses something negative about its originator; making negative statements regarding one’s own appearance or abilities, such as saying “I’m so fat” or “I’m such an idiot”; [2]
• Expressing disapproval or being critical of oneself. [3]

As with the opposite chief feature of arrogance, self-deprecation is a way of manipulating others’ perceptions of yourself in order to avoid taking a ‘hit’ to your self-esteem.


In this case, however, the basic strategy is to get in first—to launch a preemptive attack on your own failings before anyone else can do so. While the arrogant person tries to deny their imperfections by feigning perfection, the self-deprecating person believes their own imperfection is absolute: I am simply not as good as other people… And it’s perfectly obvious to everyone else, so there’s no point denying it.
Like all chief features, self-deprecation involves the following components:

1. Early negative experiences
2. Misconceptions about the nature of self, life or others
3. A constant fear and sense of insecurity
4. A maladaptive strategy to protect the self
5. A persona to hide all of the above in adulthood

Early Negative Experiences

In the case of self-deprecation, the early negative experiences typically revolve around failing to live up to parents’ high expectations.
Perhaps the parents are perfectionists and expect the child to measure up to an impossible standard. Perhaps the parents are over-achievers and cannot accept having a child who isn’t similarly talented or driven. Either way, the child can never be up to scratch.

Misconceptions

From such experiences of being constantly below standard, the child comes to perceive himself as something fundamentally flawed, basically inadequate.
Again and again, the child in this position learns that “who I am is not good enough.” The love, care and attention that he craves is unavailable, and the reason for this is—apparently—his own deficiency as a person. His constant sense of failure, and of being a constant disappointment to others, give rise to a fundamental sense of shame.
Hence:

Who I am is not good enough. Nothing I can do will ever be good enough.
I should feel ashamed of myself just for being me.
Even before I try, I know I’m going to fail—so there’s no point in even trying.
At least I will always be right about one thing: my inadequacy.
I have nothing of value to offer anyone. I don’t belong here. I am an impostor. 

Fear

Based on the above  misconceptions and early negative experiences, the child becomes gripped by a specific kind of fear. In this case, the fear is of inadequacy—never being good enough to please or satisfy others, never being good enough to deserve success or love or happiness.
The child feels like a gatecrasher in life, an uninvited guest, an interloper, and constantly fears being caught and exposed.
His attempts at living a normal life cause great internal conflict because he feels a normal life is not something he deserves, being below standard as a human being.

Strategy

The growing individual becomes hyper-sensitive to the possibility of being exposed as inadequate, and sees the threat of this exposure everywhere.
His basic strategy for coping with this threat is to manipulate others’ perceptions in advance. Typically this involves:

• avoiding others’ attention if possible: he will try to divert attention away from himself, keep the focus on other people or things;
• managing others’ expectations: to lower others’ expectations, he will tend to apologise in advance for every forthcoming “failure” and deliberately act as inadequately as possible so that no-one expects anything else.

Remember, the individual with self-deprecation truly believes in their own inadequcy. They see little point in denying it. Their ploy, then, is one of damage limitation:

I cannot succeed in life, I cannot feel good about myself, I cannot get on with others. The best I can hope for is to limit the damage by hiding myself from view.
If I am belittled, I probably deserve it. But at least if I belittle myself first, I leave others with nothing to belittle me about.

As they enter adulthood, they come to rely on this strategy more and more.

Persona

Emerging into adulthood, the individual probably does not want go around being overtly afraid and insecure about their fundamental inadequacy. Hence the defensive strategy of self-deprecation puts on a mask of invisibility. He will tend to make himself small, silent and invisible; he will tend to talk very quietly, cover his face, look downward. This mask or persona continually says to the world, “I am not here. Look the other way. Pay me no attention. And if you do happen to notice me, don’t expect anything special.”
Outwardly, he also pretends to be the most inadequate person in the world—so that anything he then manages to do just adequately or even better comes as a nice surprise to everyone and might even elicit praise.
He might even become so adept at deliberate self-deprecation that it develops into a personal style of humour, much enjoyed by other people. His obvious lack of arrogance will also be attractive to some. If he completely identifies with the sense of inadequacy, however, this could have a debilitating effect. Whenever he receives praise or appreciation, he will simply not believe it.
All people are capable of this kind of behaviour. When it dominates the personality, however, one is said to have a chief feature of self-deprecation.