The point is that abuse increases a child's risk of developing a number of health and psychological problems. 15 Children have different levels of resiliency or hardiness and different personality attributes, so different children respond differently to similarly abusive situations. That's why the lists of warning signs above seems so general. None of the symptoms above is diagnostic of child abuse - i.e., the presence of any of the signs above does not prove that abuse has occured. Also, a child may endure abuse without developing any of the symptoms above.
Abuse simply increases the risk for all of the symptoms.
Basically, children are supposed to learn everything they need to thrive in this world from their caretakers. Abusive parents provide the opposite of what children need. Instead of teaching and nurturing growth, they distort and destroy.