When I was a teen, my best friend's grandfather owned a zoo. He used to walk into the large cat cages and pet them. I talked with him about it, and he said that basically the only major difference between a lion and a housecat is size: otherwise, they're much the same, behaviorally. So when a lion is well fed and cared for, mostly it will behave like a big kitty... you just have to be careful that it doesn't try to act on funny ideas that a little kitty wouldn't, like trying to drag you around by the scruff of your neck. Of course, the main difference between a large cat in a zoo and a large cat in the wild is that one in the wild is hungry and sees you as prey, one in a zoo is well fed and sees you as "part of my food delivery staff."

At the MGM casino in Vegas, every day you can see lions in a big glass enclosure playing (just like huge kitties, playing with bouncy rubber balls etc) with their keepers, who occasionally come out to answer questions. I saw someone ask them how they determine which keeper will work with which lion. The answer was, "we let the lions choose which keeper they want to work with. We find it isn't a very good idea to try to work with a lion who doesn't like you."