INFJ view of it: For good or bad, I can't stay mad / hold a grudge / not forgive when forgiveness is pleaded. When my trust has been betrayed, I will probably show it much more intensely than an INFP, but when the emotion cools down, it's gone. It doesn't mean it couldn't take a long time if the betrayal has been severe, but I tend to forgive, cause I don't feel the emotion for long and I can understand the justifications for the person's actions. Not to say there are things that I would probably never be able to forgive - haven't come across for anything like that, but it'd prolly have to do with my values or if the person violates that trust in the first place over and over again and uses my forgiviness that way. I think.
I think it's a Fi Fe thing. When ISFP and I have fights, she tends to hold on grudges for a long time, probably forever, although she will always forgive if you mean the sorry - but I think she has some sort of map inside of her head which has blueprints of our every fight.
But I kind of agree with the poll - INFPs are probably more forgiving. Yes.