Weisskirch (2016)

To investigate whether grit, self-esteem, learning strategies, and attitudes toward lifelong learning predict estimated and achieved grades in a particular course, and explore whether self-esteem, learning strategies, and attitudes toward lifelong learning predict grit.

Cross-sectional survey

N = 302 undergraduate students; 82% female; 42% Latino

Correlation, multiple regressions,

ANOVA

Grit-PE positively correlated with estimated grade & achieved grade.

Grit-PE and Grit-CI positively correlated with estimated grade, but only Grit-PE significantly predicted it.

Self-esteem, attitudes toward lifelong learning, and GSL were predictors of Grit-PE.

Self-esteem and general strategies for learning were predictors of grit.

Latinos had higher Grit-CI and GSL score than others.

West, Kraft, Finn, Martin, Duckworth, Gabrieli & Gabrieli (2016)

To examine relationships between non-cognitive skills of charter and district school students and their academic achievement.

Cross-sectional self-report survey, with administrative and longitudinal data

N = 1368

8^th graders from 32 public schools in Boston

Correlation,

Two Stage Least Squares (2SLS) regression

Grit was positively related to attendance, behavior, math and ELA test-score gains between 4^th and 8^th grade at the student level.

Grit was not related to test-score gains at the school level.

Tucker-Drob, Briley, Engelhardt, Mann, & Harden, (2016)

To investigate how a variety of character variables (among which grit) relate with one another, with fluid intelligence, academic achievement and verbal knowledge.

Cross-sectional survey

N = 811, twins and triplets from the Texas Twin Project, 3^rd-8^th grade;

51.2% female; 61.4% non-Hispanic White;

(380 twin pairs and 51 pairs from triplet sets): 141 monozygotic (MZ) pairs, 147 same-sex dizygotic (DZ) pairs, and 143 opposite

sex DZ pairs

Correlations, regressions, CFA, EFA, SEM,

Cholesky decomposition

Character and BFI showed small associations with fluid intelligence, and larger associations with knowledge/achievement.

Character was significantly correlated with knowledge/achievement outcomes in 89% of the pairs.

Grit loaded on “Conscientiousness” as one latent factor, which was found to be 57% heritable.

After controlling for fluid intelligence, the genetic component of character, but not the environmental, was still associated with variation in the knowledge/ achievement factor.

Farruggia, Han, Watson, Moss & Bottoms (2016).

To explore what non-cognitive factors predict college success, and whether the associations between these factors and student success vary as a function of race or ethnicity.

Cross-sectional survey

N = 1603 public university 1^st year students. (53% female; 28% Latino; 28% European American, 26% Asian/Pacific islander; 49% 2^nd generation immigrant students; father of 70% not born in the US)

Multigroup CFA, correlation, SEM

Grit-PE showed positive correlations with: academic self-efficacy, GPA, motivation, time management, and sense of belonging.

Grit-PE significantly predicted academic achievement, and consequently, first-to-second year retention.

Asian American students reported the lowest levels of grit. Asian American and White students were more successful academically than Latino and African American students.

Rimfeld, Kovas, Dale & Plomin (2016)

To investigate the genetic and environmental origins of individual differences in Grit within a large representative U.K. adolescent sample, and explore the power of Grit to predict academic achievement beyond the Big Five personality traits and the extent to which this prediction is mediated by genetic and environmental factors.

Genetically sensitive research design

N = 4642 participants at age 16 (2,321 twin pairs) from the UK Twins Early Development Study (TEDS) sample (883 monozygotic (MZ) pairs, 761 same-sex dizygotic

(DZ) twin pairs and 677 opposite-sex DZ twin pairs)

Factor analysis, ANOVAs,

correlation, hierarchical multiple regression, twin method (ACE), bivariate genetic analysis

Grit-PE and Conscientiousness correlated positively but weakly with GCSE, while

Grit-CI correlated very weakly with GCSE. Grit-PE significantly predicted GCSE independently of Grit-CI, but not vice versa. Together, the two Grit dimensions explained only 2% of the variance in GCSE grades.

Grit added little phenotypically/genetically to the prediction of academic achievement beyond traditional personality factors, especially conscientiousness.