Tendency not to abandon tasks from mere changeability. Not seeking something fresh because of novelty. Not “looking for a change.”
And the other two could easily be rewritten as perseverance items for the Grit Scale.
Degree of strength of will or perseverance. Quiet determination to stick to a course once decided upon.
Tendency not to abandon tasks in the face of obstacles. Perseverance, tenacity, doggedness.
In her summary comments, Cox concluded that “high but not the highest intelligence, combined with the greatest degree of persistence, will achieve greater eminence than the highest degree of intelligence with somewhat less persistence.”
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However you scored on the Grit Scale, I hope it prompted self-reflection. It’s progress just clarifying your goals, and the extent to which they are—or aren’t—aligned toward a single passion of supreme importance. It’s also progress to better understand how well you’re currently able to persevere in the face of life’s rejection slips.
It’s a start. Let’s continue, in the next chapter, to see how grit can and does change. And, then, in the rest of the book, let’s learn how to accelerate that growth.
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I. If, for example, you scored 4.1, you’re grittier than about 70 percent of the adults in our sample.
Chapter 5
GRIT GROWS
“How much of our grit is in our genes?”
I’m asked some version of this question pretty much anytime I give a talk on grit. The nature-nurture question is a very basic one. We have an intuitive sense that some things about us—like our height—are pretty much determined in the genetic lottery, while other things—like whether we speak English or French—are a result of our upbringing and experience. “You can’t train height” is a popular expression in basketball coaching, and many people who learn about grit want to know if it’s more like height or more like language.
To the question of whether we get grit from our DNA, there is a short answer and a long one. The short answer is “in part.” The long answer is, well, more complicated. In my view, the longer answer is worth our attention. Science has made huge strides in figuring out how genes, experience, and their interplay make us who we are. From what I can tell, the inherent complexity of these scientific facts has led, unfortunately, to their continually being misunderstood.
To begin, I can tell you with complete conviction that every human trait is influenced by both genes and experience.
Consider height. Height is indeed heritable: genetic differences are a big reason why some people are really tall, some really short, and a bunch of people are of varying heights in between.
But it’s also true that the average height of men and women has increased dramatically in just a few generations. For instance, military records show that the average British man was five feet five inches tall about 150 years ago, but today that average is five feet ten inches. Height gains have been even more dramatic in other countries; in the Netherlands, the average man now stands almost six foot one—a gain of more than six inches over the last 150 years. I am reminded of these dramatic generational gains in height whenever I get together with my Dutch collaborators. They bend down solicitously, but it still feels like standing in a forest of redwoods.
It’s unlikely that the gene pool has changed all that dramatically in just a few generations. Instead, the most powerful height boosters have been nutrition, clean air and water, and modern medicine. (Incidentally, generational gains in weight have been even more dramatic, and again, that seems to be the consequence of eating more and moving around less rather than changes in our DNA.) Even within a generation, you can see the influence of environment on height. Children who are provided healthy food in abundance will grow up taller, whereas malnourishment stunts growth.
Likewise, traits like honesty and generosity and, yes, grit, are genetically influenced and, in addition, influenced by experience. Ditto for IQ, extroversion, enjoying the great outdoors, having a sweet tooth, the likelihood that you’ll end up a chain-smoker, your risk of getting skin cancer, and really any other trait you can think of. Nature matters, and so does nurture.
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Talents, in all their varieties, are also genetically influenced. Some of us are born with genes that make it easier to learn to carry a tune, or dunk a basketball, or solve a quadratic equation. But against intuition, talents are not entirely genetic: the rate at which we develop any skill is also, crucially, a function of experience.
For instance, sociologist Dan Chambliss swam competitively in high school but stopped when it seemed clear he wasn’t going to make it as a nationally ranked swimmer.
“I’m small,” he explained, “and my ankles won’t plantar flex.” Come again? “I can’t point my toes. I can only flex them. It’s an anatomical limitation. Which means, basically, at the elite level, I could only swim breaststroke.” After our exchange, I did a little research on plantar flexion. Stretching exercises can improve your range of motion, but the length of certain bones does make a difference in how flexible your feet and ankles are.
Still, the biggest impediment to improving wasn’t anatomy; it was how he was coached: “In retrospect, I look back now and can see I had horribly bad coaches in a couple of crucial places. One of my high school coaches—I had him for four years—literally taught me zero. Nothing. He taught me how to do a breaststroke turn, and he taught me incorrectly.”
What happened when Dan did, finally, experience good coaching, in part from hanging around the national and Olympic coaches he was studying?
“Years later, I got back into the pool, got in shape again, and swam a two-hundred-yard individual medley as fast as I did in high school.”
Again, same story. Not just nature, and not just nurture. Both.
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How do scientists know, with unwavering conviction, that both nature and nurture play a role in determining things like talent and grit? Over the past few decades, researchers have been studying identical and fraternal twins, raised in the same family or raised in different families. Identical twins have all the same DNA, while fraternal twins, on average, only share about half. That fact, and a whole lot of fancy statistics (well, not that fancy—more mundane, really, once a good teacher explains them to you), allows researchers to infer, from how similar the twins grow up to be, the heritability of a trait.
Very recently, researchers in London let me know they’d administered the Grit Scale to more than two thousand pairs of teenage twins living in the United Kingdom. This study estimated the heritability of the perseverance subscale to be 37 percent and the passion subscale to be 20 percent. These estimates are on par for heritability estimates for other personality traits, and in the simplest terms, this means that some of the variation in grit in the population can be attributed to genetic factors, and the rest can be attributed to experience.
I hasten to add that there isn’t just one gene that explains the heritability of grit. On the contrary, dozens of research studies have shown that almost all human traits are polygenic, meaning that traits are influenced by more than one gene. Many more, in fact. Height, for example, is influenced by, at last count, at least 697 different genes. And some of the genes that influence height influence other traits as well. In total, the human genome contains as many as twenty-five thousand different genes, and they tend to interact with one another and with environmental influences in complicated, still poorly understood, ways.
In sum, what have we learned? First: grit, talent, and all other psychological traits relevant to success in life are influenced by genes and also by experience. Second: there’s no single gene for grit, or indeed any other psychological trait.
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