What Is Grit And How Important Is It?

Grit, the Big Five personality trait known as conscientiousness, impulsivity, risk-taking, the marshmallow test, procrastination, and ADHD (also here and here and here and here) all seem to track different nuances of the same basic phenotype. which has a common genetic source. The genetic component of these traits (notwithstanding the difficulty involved in finding particular genes leading to the observed hereditary effects, but see DRD2), in particular, seems to overlap. But, this cluster of traits seems to have only a second order effect on academic outcomes with IQ, which is more strongly genetic, playing a much larger first order role in educational outcomes.

Grit—perseverance and passion for long-term goals—has been shown to be a significant predictor of academic success, even after controlling for other personality factors. 

Here, for the first time, we use a U.K.-representative sample and a genetically sensitive design to unpack the etiology of Grit and its prediction of academic achievement in comparison to well-established personality traits. For 4,642 16-year-olds (2,321 twin pairs), we used the Grit-S scale (perseverance of effort and consistency of interest), along with the Big Five personality traits, to predict grades on the General Certificate of Secondary Education (GCSE) exams, which are administered U.K.-wide at the end of compulsory education. 

Twin analyses of Grit perseverance yielded a heritability estimate of 37% (20% for consistency of interest) and no evidence for shared environmental influence. Personality, primarily conscientiousness, predicts about 6% of the variance in GCSE grades, but Grit adds little to this prediction. Moreover, multivariate twin analyses showed that roughly two-thirds of the GCSE prediction is mediated genetically. 

Grit perseverance of effort and Big Five conscientiousness are to a large extent the same trait both phenotypically (r = 0.53) and genetically (genetic correlation = 0.86). We conclude that the etiology of Grit is highly similar to other personality traits, not only in showing substantial genetic influence but also in showing no influence of shared environmental factors. 

Personality significantly predicts academic achievement, but Grit adds little phenotypically or genetically to the prediction of academic achievement beyond traditional personality factors, especially conscientiousness.

Rimfeld, Kaili, et al.,"True grit and genetics: Predicting academic achievement from personality." 111(5) Journal of Personality and Social Psychology 780-789 (November 2016).

This study doesn't find much of an impact of the Big Five trait extraversion on academic outcomes, but it is another second order factor, with an importance comparable to conscientiousness in both impact and the extent to which it is genetic, in predicting lifetime socio-economic success in other studies.