I got through watching another bad Ben Steller movie, this one featured an alien invasion, there was an alien within it who decided to betray their own kind and fight alongside the humans to prevent the invasion and save humanity, now there was the suggestion that he was a bit of a freak and into human ladies but he stated that he was impressed with humanity and was why he was making that call.
It got me thinking, its not the first time I've seen that theme, I remember in the original (decent) series of V there was an alien collaborator in the human resistance who was a religiously motivated outcast who didnt eat meat like the other lizards and who was prepared to betray his people to defend humanity too. There was also an episode of either the outlimits or twilight zone in which a guy discover that he as a deep cover agent for an invasion fleet, I think in the end being revealed as a giant ant headed bug or some kind, he goes totally crazy because he cant accept he's an alien and totally believes he human.
So my question is if you were an alien from another, vaguely humanoid species, part of an invasion force, are there enough redeeming qualities about humanity to make you want to betray your own? What would it take for you to think this way? What would the relevent criteria or factors be for you feeling how you feel?