It is an interesting question, to me, i think it has to do with we as humans when we see the “underdog” losing a small part of us wants to see a win pulled out, and to break the over confident one who looks and often seems to be the winner before it begins. My husband has admitted to me more than once when i am losing to another he finds it hot and sexy but as it becomes clear i am going to lose he cheers me on harder to come back.
And in matches where i was going to clearly walk out the winner he has secretly hoped my opponent would get that second strength and pull off a win. (None of which i get mad at him for) but i find the times i lose and he wanted to see the other Oman win, i want a rematch that much more. As for instinct? I would have to guess it falls in the same order, beit the animal kingdom or human, we choose the dominate alpha but there is that side that thinks , hopes, maybe prays the less alpha shows what she/he is really capable of. Lets face it even a timid rodent trapped in a corner will fight and bite back.