There are many different symbiotic relationships in "A Child Called It". The characters that have been mentioned were David, the child being abused, his mother, his father, and David's two brothers. One of the major relationships is the relationship between David and his mother. You could call this type of symbiotic relationship parasitism, because David is being physically and mentally abused by his mother, and his mother feels good about beating her son, calling him her slave. His mother likes his brothers more than David. This relationship would be a form of mutualism, because his mother treats David's two brothers as actual people, and her son. David's father left David, after telling him that he would try to help him escape. This could be another type of parasitism, because David's father left that situation, and was probably feeling better, and leaving David to still be physically and mentally abused by his mother. David's brothers don't really pay any attention to David, and just see him as an object, but treat him far better than his mother does. I am predicting by the end of the book, that his brothers acknowledge what is happening to David, and try and help him through his struggles, and report what is happening to him to people outside of the house.