A proper pitbull has ZERO human aggression!!!! The reason this dog most likely attacked the child is because it was a badly bred pit, that is usually what we are seeing today. Because any moron is allowed to breed a dog, genetics and temperment are rarely taken into account, so you are now seeing human aggressive pits, which is NOT what they are supposed to be. Back in the day when they were used for pit fighting, the human aggression was taken very seriously, think of it, if you had to pull a dog out of a ring in the middle of a fight you do not want it attacking you. So back in the day human aggression was not tolerated at all and dogs that displayed any human aggression was culled. A true proper pit has no human aggression at all.
Nowadays this breed is discriminated greatly and there is a stereotype that these are vicious and aggressive dogs that are dangerous for people, dogs and other animals too. Such negative stereotypes exist because the breed is viewed as such by irresponsible media that perpetuates inconsistent and wrongly reported bite data. The myriad of facts tell about aggressiveness of these dogs. The chief reason for a Pitbulls' aggression is that their owners want their dogs to be aggressive towards humans and train them this way.
Why do dog's become aggressive? What are the warning signs of dog aggression?
Dominance is often the precursor to aggression. Often, humans do not understand what dominance in dog-human terms means, because some people are not used to interpreting canine body language and warning signals, letting things slide, often without meaning to - which results in canine aggression, where your dog will put on a threatening display to keep you in your place. This is not your dog's fault. He is acting as you have entitled him to: his position as the dominant or alpha dog has been confirmed, since the owner has not corrected his behavior, and therefore it is perfectly natural for him to back up his claim-staking with an aggressive display of teeth, hackles and threatening behavior.
Warning Signs of Dominant Behavior
toy guarding: snapping, growling at you when you come close
food guarding: he may chase you away from his immediate vicinity while eating, or snap at you
furniture guarding: he may mark one or several pieces of furniture as "his own" and refuse to make way for you or get off when asked
attention demanding: barking, whining, pawing at you for attention. This will be prolonged and you will not be able to get him to stop
dinner interruptions: he may howl or whine for scraps, and generally make an incredible nuisance of himself whenever there is food around. In some cases the dog may even actively take food from you (off a plate, out of your hand, etc) without you offering it to him first