Well, for one, our bettas don't survive in the wild for the most part. The long-tailed, pampered pretty boys that we keep in our homes are the result of years, decades and centuries of specialized breeding. The wild fish are not nearly as vicious and territorial as our pet bettas are. Centuries ago, they were bred for fighting, so their vicious streak was brought out. Even today, there are some in Thailand that are bred for fighting.
In the wild, they ARE territorial, but not nearly as bad as the ones we have in tanks in our homes. They generally have a small territory that they patrol and the rice patties they live in are HUGE, so there is plenty of room for them to spread out and not infringe on one anothers territory. Wild caught bettas are known for being able to be kept in tanks together with no problems for the most part, so in the wild, they're really pretty much like any other highly territorial fish.
I think all that is right. It's how I understand it. Someone else might have some more insight....
