The Self-Castigator gets upset with himself and then becomes negative. He finds fault with his work performance, appearance, career progress, socioeconomic status, educational background, and so on. He has a very low self-concept and often say to himself, "You idiot! Why did you do that?" or "What's wrong with you? You should have known better." Quite often it is his perception about himself that is the problem. On paper, he is doing pretty well, but he never sees it that way. His favorite saying to other is "I'll take the blame, and I could have done better." Here's an example:

Supervisor: You know, Elliott, this wasn't your best work.

Self-Castigator: You're right. I can never do anything right. I hope you don't fire me for this.

Supervisor: Elliott, I have no intention of firing you. You usually do excellent work around here.

Self-Castigator: You're just saying that. I know the truth. I'm not really that good. I'll try harder though.

Supervisor: Whatever you say, Elliott.

The Solution

Find any strategy to build up this person's self-esteem. He is in desperate need of some ego boosts. You could also gather evidence to prove that they are wrong about themselves and then present him with that evidence.