The question posed here has had me thinking. Having witnessed it with my parents, dealing with it in my own marriage, and reading about it, it seems to me that even though Dr. Harley has stated that we are all wired for an affair, it is simpler than that.

We are Human and therefore imperfect by nature. Our grace/goodness comes from the ability to recognize this and our ability to forgive and love others despite their mistakes or flaws.

Or another way to put it is turtles may have different shells, size, color, thickness etc.. but in the end they are all still turtles.