Angela describes her first year of teaching Math to twelve and thirteen year olds and how some were quick to catch on to the math concepts she was teaching. After teaching the procedure for one problem, they would immediately work out the next one on their own. However, after the first grading period she was surprised that some of these talented students were not doing as well as she had expected them to. "In contrast, several of the students who initially struggled were faring better than I'd expected. These 'overachievers' would reliably come to class every day with everything they needed Instead of playing around and looking out the window, they took notes and asked questions. When they didn't get something the first time around, they tried again and again, sometimes coming for extra help during their lunch period or during afternoon electives. Their hard work showed in their grades....Talent for math was different from excelling in math class."
Most people think that math is a subject you are simply good at or you are not. Those who are more talented are expected to excel. But isn't effort important?
The next year, Angela taught at a high school. David was a freshman in her algebra class. The class she taught was the "regular" algebra class for students that hadn't scored high enough on a math placement test to be in the accelerated class. David was a quiet kid that sat in the back and rarely volunteered any answers. As the year progressed, he handed in assignments, quizzes and tests that were perfectly completed. David was clearly a student that needed to be in the accelerated track that led to the Advanced Placement Calculus class by senior year. David was switched over to the accelerated track. 
David described his experience after he was moved to the advanced class, "I was a little behind. And the next year, math--it was geometry--continued to be hard." When he didn't get A's he said he felt bad but didn't dwell on it. "I knew it was done," he said. "I knew I had to focus on what to do next. So I went to my teacher and asked for  help. I basically tried to figure out, you know, what I did wrong. What I needed to do differently." David went on to take the AP exam his senior year and earned a 5 out of 5. In college he earned dual degrees in engineering and economics, and then later a PhD in mechanical engineering. He now works as an engineer in the Aerospace Corporation. "Quite literally, the boy who was deemed 'not ready' for harder, faster math classes is now a 'rocket scientist'." (Duckworth, 2016, p. 16-20)

Angela Duckworth was curious to know the psychological make up of winners for the Scripps National Spelling Bee in Washington DC. She sent questionnaires to 273 spellers of the competition. Two thirds responded.
They completed the Grit Scale and answered some questions about how much time they devoted to spelling practice.  There was a lot of variation but the average practice time was 1 hour per day on weekdays and 2 hours per day on weekends. (Some hardly practiced at all and others practiced as much as 9 hours every Saturday.) Angela also conducted verbal IQ tests to a sample of the spellers. These results ranged from average IQ for their age to verbal prodigy. 
The winner of the spelling bee was thirteen year old Anurag Kashyap. He spelled APPOGGIATURA. Angela took the rankings of the competition and analyzed her data. "...grittier kids went further in the competition. How did they do it? By studying many more hours and, also, by competing in more spelling bees....there was no relationship at all between verbal IQ and grit. What's more, verbally talented spellers did not study more than less able spellers, nor did they have a longer track record of competition....Our potential is one thing. What we do with it is quite another." (Duckworth, 2016, p. 14)

As Angela Duckworth set out to develop a way to measure grit, she struggled with how she could measure something so intangible. "Something  that decades of military psychologists hadn't been able to quantify? Something those very successful people I'd interviewed said they could recognize on sight, but couldn't think of how to directly test for?"
She said, "I sat down and looked over my interview notes. And I started writing questions that captured, sometimes verbatim, descriptions of what it means to have grit. Half of the questions were about perseverance. They asked how much you agree with statements like 'I have overcome setbacks to conquer an important challenge' and ' I finish whatever I begin.' The other half of the questions were about passion. They asked whether your 'interests change from year to year' and the extent to which you 'have been obsessed with a certain idea or project for a short time but later lost interest.'
What emerged was the Grit Scale--a test that, when taken honestly, measures the extent to which you approach life with grit."
In 2004, the new cadets at West Point took the Grit Scale. Angela compared the grit scores with the Whole Candidate Score. There was no correlation between the two. The talent of each cadet had nothing to do with their grit. Most people think that it is the talent that makes a person endure, but as Angela explains in her book, "talent is no guarantee of grit."
"By the last day of Beast, 71 cadets had dropped out. Grit turned out to be an astoundingly reliable predictor of who made it through and who did not."
The next year, Angela returned to West Point to conduct the same study. In 2005, sixty-two cadets dropped out and the grit scale predicted who would stay again. 
"So what matters for making it through Beast? Not your SAT scores, not your high school rank, not your leadership experience, not your athletic ability.
Not your Whole Candidate Score. 
What matters is grit." (Duckworth, 2016, p. 8-10)

​"Each year in their junior year of high school, more than 14,000 applicants begin the admissions process. This pool is winnowed to just 4,000 who succeed in getting the required nomination. Slightly more than half of those applicants---about 2,500---meet West Point’s rigorous academic and physical standards, and from that select group just 1,200 are admitted and enrolled. Nearly all the men and women who come to West Point were varsity athletes; most were team captains. And yet, one in five cadets will drop out before graduation. What’s more remarkable is that, historically, a substantial fraction of dropouts leave in their very first summer, during an intensive seven-week training program named, even in official literature, Beast Barracks. Or, for short, just Beast.
Who spends two years trying to get into a place and then drops out in the first two months?”
Who makes it through Beast? Angela Duckworth, the author of Grit, set out to answer this question. She describes in her book how many psychologists tried to develop tests to determine who would stay and who would leave. None of the tests had a correlation with those who would drop out.
Angela continues, “Soon after learning about Beast, I found my way to the office of Mike Matthews, a military psychologist who’s been a West Point faculty member for years. Mike explained that the West Point admissions process successfully identified men and women who had the potential to thrive there. In particular, admissions staff calculate for each applicant something called the Whole Candidate Score, a weighted average of SAT or ACT exam scores, high school rank adjusted for the number of students in the applicant’s graduating class, expert appraisals of leadership potential, and performance on objective measures of physical fitness. …In other words, it’s an estimate of how easily cadets will master the many skills required of a military leader.
The Whole Candidate Score is the single most important factor in West Point admissions, and yet it didn’t reliably predict who would make it through Beast. In fact, cadets with the highest Whole Candidate Scores were just as likely to drop out as those with the lowest.”
Angela began interviewing individuals that were highly successful in business, arts, athletics, etc., to determine what made them unique. She discovered that what set them apart was that they keep going after failure, especially when it is not easy. “Even if some of the things they had to do were boring, or frustrating, or even painful, they wouldn’t dream of giving up. Their passion was enduring. In sum, no matter the domain, the highly successful (have) a kind of ferocious determination that (plays) out in two ways. First these exemplars were unusually resilient and hard working. Second, they knew in a very, very deep way what it was they wanted. They not only had determination, they had direction. It was this combination of passion and perseverance that made high achievers special. In a word, they had grit."
(Duckworth, 2016, p. 3-8)