Much would depend upon which animal it was. Primates have different social structures (broadly) than ungulates, rodents, carnivores, etc. If I had to guess, I'd say that the need for security underpins aggression. Every order has unique needs, and strategies to ensure immediate survival.

But increased intelligence might bring an expanded awareness of their species and concerns for its survival, as well. So even a normally docile species could evolve into a more aggressive or destructive one.

Take as an example, animals whose continued presence on the planet depended on overwhelming predation pressures with huge litters of offspring. Maybe the more dextrous ones would develop building behaviors (like the beaver, ants or termites did) to protect their societies.

Or maybe some species would develop weapons. Both strategies served humans well, right away.

Ungulates might be better served to continue their domestic roles, but as partners, rather than servants, of humans. The docile herd mentality could be beneficial to us as an adjunct to our shortsighted, selfish tendencies.

It's an interesting thread. Also, it's 0230 and I need sleep. :O)