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.

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

There ya go, thats your answer.

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

industry had made the u.s. the richest nation in the world at this time. the second industrial revolution caused growth in industry and transportation, which allowed increased trade between nations. click to let others know, how is it