2:47 one characteristic emerged as a significant predictor of success. And it wasn't social intelligence. It wasn't good looks, physical health, and it wasn't I.Q. It was grit. Grit is passion and perseverance for very long-term goals. Grit is having stamina. Grit is sticking with your future, day in, day out, not just for the week, not just for the month, but for years, and working really hard to make that future a reality. Grit is living life like it’s a marathon, not a sprint.
http://bridge-english.blogspot.jp/2012/09/blog-post_5537.html 不屈の精神を英語でなんと言うか?