It is communicating that their performance is never quite good enough - it can always be better. Some kids figure out early that they can't win the battle for their parents' love and approval and so they give up trying. Instead, they act out their pain with behaviors meant to prove to everyone that they can't measure up. Children who give up often become the scapegoat, or black sheep of the family, letting family members heap all the blame for everything that's wrong in the family on them. Have reasonable expectations for your child.
Several factors are important here.
First, know what is age appropriate behavior. Perfectionistic parents often feel anxious about behaviors in their children that are quite appropriate for their age level. Just because a toddler throws her oatmeal on the floor today, doesn't mean she will continue that behavior at 35. Books, classes and parents' support groups can help you stay in touch with what's normal for your child at various levels of development. Secondly, get to know and accept your child for who he is.