Okay fine. Yes, maybe I did really do that- I did take that last beautiful Lindt chocolate ball from the baby when she wasn’t looking… It was just so good I couldn’t resist! Any normal human being in that situation (well perhaps they never would have gotten there…) would feel guilty (sorry I forgot to feel guilty while I was enjoying the sweet milk chocolate melt in my mouth). What is “guilt”? It is an emotion in the general category of negative feeling states such as grief and loneliness. What is the evolutionary purpose of guilt and can it be taken too far?
As we are social animals, usually living in communities together, guilt is the feeling that will make us more compatible with each other. If you stole someone else's food, yet then showed remorse, it would be easier for that person to forgive you. Being forgiven will stop the community from rebelling against you and perhaps casting you out of the safety of the group. In addition, it will maintain reciprocal altruism. For example, I'll give you some of my food even though I'll go hungry because I expect you to do the same in the future. You most likely will because you would feel guilty if you didn't. Therefore, guilt helps us maintain beneficial relationships, a necessity for our survival.
As all things taken to the extreme however, guilt can turn into a crippling feeling. It manifests in anxiety disorders, particularly, depression, social phobia, obsessive-compulsive disorder, eating disorders such as anorexia, body dysmorphic disorder, bipolar mood disorder, and in schizophrenia it has been described as being one stage in the construction of delusion.
Oh, and by the way, stop looking at me like that… Yes, you, reader. I know you’re judging me behind the safety on the computer screen. I won’t justify my actions to you! Not when it comes to chocolate!