Aggressive dogs caused by owner error?

There are also lots of dogs chained outside day in and day out starved for attention and sweet as can be. Jast as there are lots of dogs who are doted on day in and day out who have excellent manners. Aggression can be an inheritable trait and can show up at any point in a dogs life. Some breeds are more prone to aggression then others. You are also getting into the debate "Nature vs Nurture". Is the dog aggressive because the way it was raised? Is the dog aggressive because of its breed and genetics? There is NO one answer for these questions as it is a combination of things that lead to aggression in animals as well as people.