Grit: The Power of Passion and Perseverance · chapter 4 · id grit-c4-07-grit-is-heritable-but-not-fixe
“Grit is heritable but not fixed -- approximately 37-48% of variation in grit is explained by genetics, leaving substantial room for environmental influence.”
TRUE, BUTconfidence: medium⚠ extracted by pipeline, re-audit pending
Receipts
PMC (2016) - True grit and genetics: predicting academic achievement from personalitysource alive
Grit was 37% heritable for perseverance of effort and 20% for consistency of interest, with about 50% of genetic variance shared with conscientiousness.
Polderman et al. (2015), Nature Genetics - heritability meta-analysissource alive
Across all personality traits, reported heritability averages 49%. Shared environmental influence is negligible for most personality traits.
Brookings Institution - Time to Flit the Gritsource alive
Shared environment has a negligible effect on grit, which means that current differences between families and schools explain little variance in grit development.
This claim is a stable, citable object. If you can falsify a verdict, tell us. Corrections are loud here.