Having "grit" is more likely a symptom of coming from privilege. The marshmallow experiment comes to mind. Some kids were able to resist the urge to not eat the marshmallow for the promise of getting two if they waited. Others could not. The kids that could defer reward ended up having better life outcomes. In retrospect it was a test for privilege. Kids from poorer backgrounds tended to go for the immediate reward of the marshmallow. The test really showed that privileged kids have better life outcomes than kids that don't have privilege. Not really a surprising outcome.