Jim,
capturing the "correct" personality assumes that you know what it is. Often, a one or two-hour photo session isn't enough time to get to know an animal so well that you can tell a "false" personality from the "correct" one. So I pretty much assume that what the animal shows me is what he/she is. And, when it comes to dogs at least, I have magic hands so I get good interaction from them. I've also shot my fair share of rescues and, generally speaking, if I can get them to show some personality -- which is the objective since we're trying to get them adopted -- it is in fact a true representation of what the dog is really like.

While I do agree that it's easier to find the right expression when you really know the animals well, I don't think that getting animals to be animated in a portrait session forces them to show an "incorrect" personality. Under those circumstances, that's how they behaved. There's nothing incorrect about that. However, I think you are more likely to capture the true essence of a particular animal if you reduce the stress of the situation by shooting them in their home environment, with available light, with things and people they love, etc. Unfortunately, we can't always do that. So what we get in our studios with strobes flashing away is what they are in that environment at that moment in time. Which is also part of their personalities.

Jim