Sounds like it is predictive. Just not when: > Controlling for differences such as household income and cognitive abilities ... So it's a (predictive) IQ test

Sounds like it is predictive. Just not when: > Controlling for differences such as household income and cognitive abilities ... So it's a (predictive) IQ test. Perhaps it disavows the prior assumed basis of "deferred gratification", but not the predictive power of the test.