Abuse isn't the only way to harm a child. Neglect can be as destructive, says CyberShrink. Children need constant care and affection, and parents are the ones who have to supply this. He also says that children can be damaged by being overlooked by parents and adults who pay no attention to what they're doing. Or who only pay attention to the child when it gets into trouble.
In such situations, children learn no positive community and personal values, and indeed may only feel important when they create a crisis. Such children are being deprived of a childhood - a very important time when skills are learned and attitudes are developed. Children who have troubled childhoods carry what they learn into adult life. In short, being a parent is a huge responsibility and not one that should be taken on without being fully aware of this.