People love personality tests, and I'm no exception, so I was thrilled to find a copy of the "grit scale" in Angela Duckworth's new book, "Grit."

Your agreement or disagreement with 10 statements, including "I often set a goal but later choose to pursue a different one" and "I have overcome setbacks to conquer an important challenge," produces a total grit score, which reveals how much passion and perseverance you typically display. (You can take a 12-item version of the scale here.)

Your grit score is important because, according to Duckworth, a professor of psychology at the University of Pennsylvania, it strongly influences how far you'll go in life.

Duckworth's research has found that the average American scores about 3.8 on a scale of 1 (not at all gritty) to 5 (extremely gritty).

Unfortunately, I scored a 3, putting me in the 20th percentile of the American population.

And while I could have given up right there, thrown the book away and declared myself a hopeless cause, how gritty would that be?

Not very — and not very wise, either. That's because Duckworth says grit is something that can be developed and worked on over time.

In fact, the book includes a copy of a graph showing that most 25- to 34-year-olds score between 3.4 and 3.5 on measures of grit, while those 65 and older score nearly 4.

Presumably, that's the result of the normal process of maturation. But Duckworth has lots of advice for people who want to actively grow their grit — and up their chances of personal and professional success.

When Duckworth visited the Business Insider offices in April, she said your grit score is "like a snapshot in time."

She continued:

I don't think of people as snapshots; I actually think of them as movies.

How you are today isn't necessarily how you were last year, and it's certainly not necessarily how you're going to be the following [year]. And so the question of, "Can I grow my grit?" I think is answered unequivocally by "yes."

Duckworth's research has identified four components of grit: interest, practice, purpose, and hope, which generally develop in that order.

Interest, Duckworth says, is the seed of passion. You have to find something you genuinely love and find meaningful, or else there's no chance you'll want to pursue it for the long haul.

Practice means constantly wanting to improve on the area that interests you, and committing to challenging yourself on a daily basis.

Purpose is about feeling like your work matters to you and to the rest of the world.

Hope, which Duckworth says characterizes every stage of grit, involves the ability to keep going even when the going gets tough.

Another key component of developing grit is finding a gritty mentor. Duckworth told us that your mentor can be anyone — your boss, your colleague, or your grandparent — who demonstrates passion and perseverance themselves.

She said gritty mentors must provide both challenge and support.

As for the importance of challenge, she explained, "One of the reasons we need mentors is they say, ‘You know, that wasn't good enough. Let me show you or tell you how that could be done differently or better.'"

A supportive mentor will let you know that they can help you and that they always have your back.

"Challenge without support is just discouraging and stressful," she said. "However, support without challenge is just complacency."

So all is not lost for those who take the grit scale and score lower than they would have liked. But grit won't magically grow — it's up to you to develop it, bit by bit, day by day, until you achieve your most important goals.