Question

In an Israeli study of seventh to ninth graders, after controlling for participants' age, researchers found that __________ fully accounted for early adolescent gains in propositional thought.

Answer 1

In an Israeli study of seventh to ninth graders, after controlling for participants' age, researchers found that years of schooling fully accounted for early adolescent gains in propositional thought

Answer 2

So basically the answer is pretty simple...Years of schooling !

There ya go, thats your answer.