Grit: The Power of Passion and Perseverance · chapter 5 · id grit-c5-04-the-maturity-principle-in-pers
“The maturity principle in personality psychology shows that people become more conscientious, agreeable, and emotionally stable as they age, and grit follows a similar pattern.”
CONTESTEDconfidence: medium⚠ extracted by pipeline, re-audit pending
Receipts
Journal of Demographic Studies - Does Aging Make Us Grittier?source alive
In cross-sectional studies, grit increases monotonically with age. But longitudinal data shows no within-person age-related increase, suggesting cohort effects rather than maturation.
Scientific Reports (2021) - Genetic and environmental architecture of conscientiousnesssource alive
The maturity principle -- that people become more conscientious with age -- is well-established in longitudinal personality research.
PMC (2016) - True grit and geneticssource alive
About 50% of grit's genetic variance is shared with conscientiousness, suggesting they develop along similar trajectories.
This claim is a stable, citable object. If you can falsify a verdict, tell us. Corrections are loud here.