Emotional abuse is the systematic diminishment of another. Emotional abuse can be as random as the fallout from a nuclear explosion. In matrimonial battles, for example, the children all too often become the battlefield. I remember a young boy, barely into his teens, absently rubbing the fresh scars on his wrists. His mother and father were locked in a bitter divorce battle, and each was demanding total loyalty and commitment from the child.
Emotional abuse can be active.
I'm ashamed you're my son. It also can be passive, the emotional equivalent of child neglect a sin of omission, true, but one no less destructive. And it may be a combination of the two, which increases the negative effects geometrically. Emotional abuse can be verbal or behavioral, active or passive, frequent or occasional. Regardless, it is often as painful as physical assault.