In my view this submission is vapid to the point of being flag-worthy. Evidence: after two hours this piece has generated zero actual discussion.
Here's an interesting obvservation I've had about tenacity. My company has inspired a small niche in the conference industry. There is one other company that launched at the same time as us and six more that are copycats. One thing I've noticed is that the copycats are full of bluster but light on tenacity. I think having the original idea gives you extra backbone because you are tied to the change you want to see in the world. Copycats just see a business opportunity and start to doubt themselves when they hit rough patches.
Your environment can chisel an "edge" into your personality. Something like a chip on your shoulder. Doesn't this happen a lot in small teams? You against the world? Soldiers in small military units, startups, and again, sports see similar "effects".
Adversity or emotional abuse might produce a similar result. A parent telling a child that something isn't good enough or to not let them down on a task.
Isn't this loosely related to all those posts about not telling kids they're smart?
http://espn.go.com/blog/truehoop/post/_/id/11562/the-essenti...
This is about probable NBA hall-of-famer Reggie Miller and how he turned into a renowned trash talker. Apparently a lot of the drive came from growing up under the thumb of his even more successful older sister. The day he scored 40 points in a high school game was the day she scored 105. He couldn't beat her one-on-one until he was an adult. Now trash-talking is not the same as success, but it takes some tenacity to keep challenging people no matter how the game is flowing.
How many of us wish our parents and siblings were meaner?