I believe it can be both: You should not breed a dog that is overly timid or has fear aggression, but I think that it is the way the dog is raised mostly (on a chain, no socialization, hitting, or kicking, starving, and any neglect are what cause aggression. There are some breeds that are more prone to bite, but not beacuse they are aggressive but because they were bred to guard and they will protect what they feel they should even if it requires biting. I do not like to recommend dog breeds to anyone without know them. I guess if I had to I would recommend an ADULT from a shelter, if the person was instant on a breed I might recommend a Standard Poodle, Beagle, or maybe even a Pug. I would choose a medium size dog that is intelligent and eager to please, that does not have major grooming issues. I would not recommend most large breeds, but I definitly would not recommend any Bully Breeds (including Boxers, Bulldogs, PittBulls, Staffshire Terriers, ect), or Shepards, Rottweilers, Shar Peis, Chows, Terriers, Huskies, Malamutes, or any Mastiffs. The reason being is I love most of these breeds, especially the Bully Breeds, and I have seen way to many who are abandoned, because people are not able to train them. The owners are not strong enough leaders and the owner is not able to control and train the dog. This causes the dogs to remain unsocialized and untrained which can lead to disastrous situation. It is what also causes alot of owners to hit, kick, beat, and tie the dog out on a chain until they grow tired of it and dump it for someone else to deal with. I would never recommend a puppy for a first time owner, because they are so difficult to raise. That is just my opionion. Sorry about mispellings, spell check not working.