Does Grit Predict Success Better Than Talent?

Every summer, roughly twelve hundred teenagers arrive at the United States Military Academy at West Point for six and a half weeks of training that everyone there calls Beast Barracks. They get up before dawn, they are shouted at, they march, and a few of them go home. Each has already cleared an admissions process scoring school rank, college entrance exams, physical fitness and leadership. In the summer of 2004, on top of all that, they were handed a short questionnaire and asked to rate statements like «I finish whatever I begin».

The questionnaire belonged to Angela Duckworth, then a doctoral student in psychology at the University of Pennsylvania. It measured what she named grit: passion and perseverance for long-term goals. When she looked at who left that summer, her twelve questions did better than the admissions score.

The paper reporting this, written with the Michigan psychologist Christopher Peterson and two West Point officers, Michael Matthews and Dennis Kelly, has been cited thousands of times (Duckworth, Peterson, Matthews & Kelly, 2007). It grew into a TED talk watched more than 38 million times on TED’s own site, a bestselling book, and a line that most people can now recite without knowing where it came from: talent is overrated, grit is what counts.

So does grit predict success better than talent or IQ? The material for an answer is sitting in the same papers that made grit famous, plus one meta-analysis that read all of them at once.

The number in the abstract that nobody quotes

The 2007 paper contains six studies: two samples of American adults, one of Ivy League undergraduates, two West Point classes, and one set of finalists at the Scripps National Spelling Bee. Its Table 3 sums them up in a single column headed «% variance in success explained by grit». The six entries read 4.8, 4.8, 6.3, 3.9, 1.4 and 3.8. The abstract puts it plainly: grit «accounted for an average of 4% of the variance».

Four percent is worth translating. Take a hundred cadets and everything that will decide how their first year goes: sleep, injury, homesickness, the platoon they land in, how good they are at maths. Grit is one strand in that rope, holding about a twenty-fifth of the weight. That is a genuine signal, roughly what a decent personality questionnaire usually buys you. It is not a searchlight.

The 4% is also an average. The lowest figure in the table, 1.4%, comes from the second West Point class, the same setting that made the finding famous.

Inside the founding study, talent won most of the races

West Point condenses its admissions judgement into one number, the Whole Candidate Score: high school rank, college entrance exam score, a leadership rating from extracurricular activities, and a standardised physical exam. If «talent» has an institutional definition, that is it.

In the class of 2008, 94.2% of cadets finished Beast Barracks and 5.8% left. Grit predicted who stayed. The Whole Candidate Score did not predict it at all. That is the result everyone repeats, and it holds.

Then the academic year began and the order reversed. Among cadets who stayed, the Whole Candidate Score predicted first-year academic grades at r = .64 and military performance at r = .42. Grit predicted academic grades at r = .06. Hold the admissions score and self-control constant, and grit’s link to grades vanished: partial r = −.01, which is a polite way of writing zero.

Read closely, the founding paper says something narrower than the slogan it produced. Talent, measured the way West Point measures it, predicted how well cadets performed. Grit predicted one thing: who packed a bag in July.

The arithmetic behind «99% more likely»

Two years later Duckworth and Patrick Quinn, also at Pennsylvania, shortened the scale to eight items and tested it on another West Point intake (Duckworth & Quinn, 2009). One sentence from that paper went everywhere: «Cadets who scored a standard deviation higher than average on the Grit–S were 99% more likely to complete summer training».

Read as ordinary English, that promises something enormous: your chance of surviving Beast Barracks nearly doubles. Read as statistics, it says the odds ratio was 1.99, and odds are not chances. When almost everybody finishes, the two numbers pull very far apart.

Marcus Credé, then an assistant professor of psychology at Iowa State University, worked out what the sentence means in cadets: «This interpretation is incorrect because approximately 94% of all cadets successfully completed the program.» Moving a completion rate from 95% to 97.5% doubles the odds too, and, as he put it, «this is only a 2.6% increase in the likelihood of completing the program» (Credé, Tynan & Harms, 2017).

A doubling of odds sounds like the gap between failing and passing. Here it is the gap between one cadet in twenty going home and one in forty.

What 66,807 people looked like once you added them up

Credé, with Michael Tynan of Iowa State and Peter Harms of the University of Alabama, pooled every grit study they could code: 584 effect sizes, 73 studies, 88 independent samples, 66,807 people. The correlations below are corrected for measurement error, which flatters grit rather than the reverse.

Grit and…	ρ	Samples / people
academic performance	.18	39 / 13,141
performance outside school	.21	7 / 4,116
staying in a programme	.18	10 / 11,163
cognitive ability	.05	21 / 11,513
conscientiousness	.84	22 / 18,826
self-control	.72	4 / 2,615
perseverance of effort → academic performance	.26	11 / 5,221
consistency of interest → academic performance	.10	11 / 5,221

The link with performance, .18, is small and real. Sort a lecture hall by grit score and then by grades, and the two orders would agree far more often than chance and far less often than the TED talk implies.

The number that broke the construct is further down: grit and conscientiousness correlate at ρ = .84. To feel the size of that, use the comparison Credé’s team drew. Two different questionnaires, both built to measure conscientiousness, typically agree at about ρ = .63. The grit scale agrees with conscientiousness measures more closely than conscientiousness measures agree with each other. Their phrase for this was «old wine in new bottles».

Put both traits into one regression and the consequence shows up. Overall grit «explains no variance in either overall academic performance or high school GPA after controlling for conscientiousness», and adds ΔR² = .004 to college grades. Four thousandths. Run it the other way and conscientiousness still adds something after grit is accounted for.

One half of the scale did survive. The grit questionnaire splits into perseverance of effort («I finish whatever I begin») and consistency of interest («my interests change from year to year», scored in reverse). Perseverance added ΔR² = .040 to overall academic performance and .085 to high school grades with conscientiousness held constant. Consistency added almost nothing, and its regression weights sometimes turned negative.

The passion half of «passion and perseverance» is the half that fails to earn its place. What is left is the ordinary, unglamorous business of finishing things, which psychology had already been measuring for decades.

Twins, and everyone who never applied to West Point

Two later studies attacked the weak points from opposite sides. The first went at the overlap with conscientiousness through genetics. Kaili Rimfeld and colleagues at King’s College London used 4,642 sixteen-year-olds, 2,321 twin pairs, from a long-running British twin study, and predicted their national exam grades (Rimfeld, Kovas, Dale & Plomin, 2016). Personality as a whole explained about 6% of the variance in grades. Grit added 0.5% on top. The genetic correlation between grit’s perseverance half and Big Five conscientiousness came out at 0.86: whatever inherited tendencies push one score up push the other up almost in step.

The second went at a subtler problem, which is who gets studied. West Point cadets, Ivy League undergraduates, spelling bee finalists and Special Forces candidates share a property. All of them have been filtered for ability. In a group already screened on talent, talent stops varying much, and anything that still varies looks strong by comparison. Statisticians call this range restriction: it is why a study of professional basketball players will tell you height barely matters.

Chen Zisman and Yoav Ganzach, then at Tel Aviv University, redid the comparison in a nationally representative American sample instead: several thousand people born in the early 1980s and followed by a federal labour-market survey, with intelligence measured in their teens and grit measured in their thirties (Zisman & Ganzach, 2021). Their finding, in their own words: «intelligence contributes 48–90 times more than grit to educational success and 13 times more to job-market success». Conscientiousness also beat grit, by a factor of about two.

They also explain the discrepancy with the earlier work, and the explanation is neat. In the Ivy League study, grit had correlated negatively with entrance exam scores, which looked like evidence that grit and talent are opposites. In a place with an admissions bar, students who got in on lower test scores had to be bringing something else through the door. Remove the bar and the correlation between grit and intelligence disappears.

What Duckworth said when the meta-analysis landed

The meta-analysis went public in May 2016, three weeks after Duckworth’s book reached number two on the New York Times bestseller list. She answered in emails to the education reporter Anya Kamenetz at NPR (Kamenetz, 2016), and the answers are worth reading, because she gave ground on the two points that carry the weight.

On the odds-ratio sentence: «Crede is right that I should have said [it that way] … but again, the tables and statistics are entirely correct, and the intent was not to mislead!»

On the size of the effect, she told NPR she did not disagree, and placed her own findings where personality psychologists place most findings: the small-to-medium range.

On conscientiousness, she said she would rather think of grit as «a member of the conscientiousness family», one with predictive power of its own. That is a considerably smaller claim than the one on the book jacket, and it is close to what Credé’s team argued.

Set that beside the sentence from her 2013 TED talk that most people carry around: «And it wasn’t social intelligence. It wasn’t good looks, physical health, and it wasn’t IQ. It was grit.»

The strongest test of the claim is Duckworth’s own

In 2019 she went back to West Point with a decade of records: 11,258 cadets across nine entering classes, each measured before training on grit, cognitive ability (entrance exam scores) and physical ability, then followed through to graduation (Duckworth, Quirk, Gallop, Hoyle, Kelly & Matthews, 2019). This is the design her critics had asked for: prospective, longitudinal, outcomes from official records.

The results split by outcome:

• Getting through Beast Barracks. Grit, alone. Cadets a standard deviation above their peers had 54% greater odds of finishing. Cognitive ability and physical ability did not reliably predict it.
• Academic grades across four years. Cognitive ability, by a distance (β = 0.41). It was also the best pre-training predictor of military grades (β = 0.16).
• Graduating within four years. Grit and physical ability (both OR = 1.18) beat cognitive ability (OR = 1.08).

The paper’s own summary of grit: it «contributed only modestly to academic, physical, and military performance but was the only reliable predictor of completing Beast Barracks».

There is a defensible version of the grit claim in there, and it is specific. Grit wins when the outcome is not quitting: surviving a short, brutal, voluntary ordeal, or finishing a long programme you have already entered. Talent wins when the outcome is performing: grades, rankings, how good the work is once you are in the room. Most of the time, when people say «success», they mean the second thing.

Where the count stands now

Grit did keep predicting retention outside the military. An earlier study by Lauren Eskreis-Winkler and colleagues at Pennsylvania followed soldiers in a Special Operations selection course, sales representatives, Chicago high school juniors and married adults, and found grittier people stayed in all four, over and above the usual predictors (Eskreis-Winkler, Shulman, Beal & Duckworth, 2014). The authors describe the effects as small or small-to-medium, which is the honest description and rarely the one that travels.

The largest tally so far comes from Kelly Lam and Mingming Zhou at the University of Macau, who pooled 137 studies, 156 samples and 285,331 students across many countries (Lam & Zhou, 2022). Overall grit and academic achievement: weighted r = .19. Perseverance of effort: .21. Consistency of interest: .08. Individualist and collectivist cultures gave the same picture: four times the data, the same shape as 2017.

Grit is one of a family of school-friendly traits that arrived with big promises and shrank under replication. We traced the same arc for Carol Dweck’s growth mindset once large pre-registered trials tested it and for the claim that emotional intelligence accounts for most of career success.

If you want the pattern rather than the case, the visual-auditory-kinaesthetic learning styles idea shows what happens when a construct is adopted by schools before anyone tests it, and our register of checked self-improvement claims keeps the running tally. Another idea from the same decade that shrank once the samples grew is power posing.

Sources

• Duckworth, A. L., Peterson, C., Matthews, M. D., & Kelly, D. R (2007). Grit: Perseverance and passion for long-term goals. Journal of Personality and Social Psychology. 92(6), 1087-1101; the founding paper. Grit accounted for an average of 4% of the variance in success outcomes (Table 3: 4.8, 4.8, 6.3, 3.9, 1.4, 3.8 percent). In the class of 2008, 94.2% completed summer training; grit predicted retention while the Whole Candidate Score did not, but the Whole Candidate Score predicted first-year academic GPA at r = .64 and military performance at r = .42, against grit's r = .06 for GPA and partial r = -.01 after controls. doi:10.1037/0022-3514.92.6.1087
• Duckworth, A. L., & Quinn, P. D (2009). Development and Validation of the Short Grit Scale (Grit-S). Journal of Personality Assessment. 91(2), 166-174; source of the sentence 'Cadets who scored a standard deviation higher than average on the Grit-S were 99% more likely to complete summer training' (p. 171), reporting an odds ratio of 1.99. doi:10.1080/00223890802634290
• Crede, M., Tynan, M. C., & Harms, P. D (2017). Much ado about grit: A meta-analytic synthesis of the grit literature. Journal of Personality and Social Psychology. 113(3), 492-511; 584 effect sizes, 73 studies, 88 samples, 66,807 people. Grit and academic performance rho = .18 (k=39, N=13,141); non-academic performance rho = .21; retention rho = .18; cognitive ability rho = .05; conscientiousness rho = .84 (k=22, N=18,826); self-control rho = .72. Perseverance of effort rho = .26 with academic performance against consistency of interest rho = .10. Overall grit explains no variance in overall academic performance or high school GPA after controlling for conscientiousness (delta R-squared = .004 for college GPA); perseverance adds .040, .085 and .023. Also corrects the '99% more likely' reading: approximately 94% of all cadets completed the program, an effect equivalent to about a 2.6% increase in likelihood. doi:10.1037/pspp0000102
• Rimfeld, K., Kovas, Y., Dale, P. S., & Plomin, R (2016). True grit and genetics: Predicting academic achievement from personality. Journal of Personality and Social Psychology. 111(5), 780-789; 4,642 UK sixteen-year-olds (2,321 twin pairs). Personality explained about 6% of variance in GCSE grades and grit added 0.5%; genetic correlation between grit perseverance and Big Five conscientiousness was 0.86, phenotypic correlation 0.53. doi:10.1037/pspp0000089
• Zisman, C., & Ganzach, Y (2021). In a Representative Sample Grit Has a Negligible Effect on Educational and Economic Success Compared to Intelligence. Social Psychological and Personality Science. 12(3), 296-303; nationally representative NLSY97 sample. Intelligence contributed 48-90 times more than grit to educational success and 13 times more to job-market success; conscientiousness contributed about twice as much as grit. Attributes earlier grit findings to range restriction in selected samples. doi:10.1177/1948550620920531
• Kamenetz, A (2016). MacArthur 'Genius' Angela Duckworth Responds To A New Critique Of Grit. NPR Ed. Duckworth's own published response to Crede et al., by email: she agreed on the '99% more likely' wording ('Crede is right that I should have said [it that way] … but again, the tables and statistics are entirely correct, and the intent was not to mislead!'), did not dispute the small-to-medium effect size, and said she would prefer to think of grit as 'a member of the conscientiousness family'. npr.org
• Duckworth, A. L., Quirk, A., Gallop, R., Hoyle, R. H., Kelly, D. R., & Matthews, M. D (2019). Cognitive and noncognitive predictors of success. Proceedings of the National Academy of Sciences. 116(47), 23499-23504; 11,258 West Point cadets across nine entering classes. Grit gave 54% greater odds of completing Beast Barracks (OR = 1.54) while cognitive ability (OR = 1.06) and physical ability (OR = 1.08) did not reliably predict it; cognitive ability was the strongest predictor of academic (beta = 0.41) and military (beta = 0.16) grades; grit and physical ability (both OR = 1.18) beat cognitive ability (OR = 1.08) for four-year graduation. doi:10.1073/pnas.1910510116
• Eskreis-Winkler, L., Shulman, E. P., Beal, S. A., & Duckworth, A. L (2014). The grit effect: predicting retention in the military, the workplace, school and marriage. Frontiers in Psychology. 5:36; grit predicted retention over and above established predictors among Army Special Operations Forces candidates, sales representatives, Chicago high school juniors and married adults; the authors describe the effects as small or small-to-medium. doi:10.3389/fpsyg.2014.00036
• Lam, K. K. L., & Zhou, M (2022). Grit and academic achievement: A comparative cross-cultural meta-analysis. Journal of Educational Psychology. 114(3), 597-621; 137 studies, 156 dependent samples, N = 285,331. Overall grit and academic achievement weighted r = .19; perseverance of effort r = .21; consistency of interest r = .08; no difference across individualism-collectivism. doi:10.1037/edu0000699