I've seen a lot of both labs and goldens with aggression issues. We refer to them as "Mock-Labs" and Mock-Goldens". The majority of them with issues we've seen in this area have a very distinct look/behavior to them. Many are longer and leaner than the 'typical' retriever, with narrow, pointy heads, high pitched barks, and off-the-wall energy. And I'm not refering to field-bred variations of the breeds; this is something totally different. I'm sure there are some beautiful looking examples of the breeds that also have those aggression issues, but it does seem most of them have that look. It is really scary how quickly a breed can mutate from their original type to something so far removed from it.