My father was one of the most noble human beings I have ever known. He was a man of the most sterling integrity, profoundly honorable and honest, a heroic patriot in his military career and self-sacrificing in his personal life. I never knew him to tell a lie.
Yet he told me that the reason he was so honest is that in every single exchange he had he was tempted to lie, to take the easy way out. He had to constantly guard his tongue and monitor his words so he would say what was accurate, rather than embroidered, exaggerated, evasive, or completely untrue. For his whole life.
The result was that he was unfailingly honest, to the very penny, in all of his public and private dealings and in all his speech. Yet by the standard of these researchers, he was not honest because it wasn’t easy or natural.
My take is that you are what you do. Seems to me that your father was an honest man.
When I would see Dubya answering questions it would seem to me that he was measuring his words so to avoid lying. I thought him often evasive so to avoid lying. If I'm right then was he being honest or not?
Your father was telling you that he had the nature of a dishonest man, but chose to be an honest man. This might have been a very valuable lesson for you.
There are many examples of this kind of behavior. We call it "resisting temptation". It is so basic in humans, that we even have an example in the Bible, of Satan tempting Jesus, and Jesus resisting.
It is easy to behave correctly if you are not tempted, but requires an act of will when you are. The useful aspect of this Harvard study lies not in catagorizing people as "honest" or "dishonest" by nature, but in recognizing that one will get to a honest response in a different way, depending on the underlying nature. This is an important step toward developing a reliable lie detector.