It's just not confined to yourself. Guilt is tied into some kind of interpersonal context. The writer also points out that guilt helps people in close relationships control each other's behavior. So you could use guilt to control people. Guilt is a good strategy for the weaker person in the relationship.
Guilt is a power-equalizing strategy.
If you feel guilty over not taking out the garbage, chances are your spouse who wanted the garbage taken out will feel better knowing that. In this way, emotional equity is restored because bad feelings are restored to the person who caused them. Feeling guilty is a way of showing that one cares. Then he makes an interesting departure from the more pragmatic approach to guilt. Well, the data are converging on two sources.