Intelligence and the Holy Grail

Our inquiry might well end here, admittedly having failed to identify the Holy Grail through the study of self-esteem. We might instead entertain another search: Setting aside self-esteem, is there any other variable that does what we thought self-esteem did? Perhaps it is a variable overlooked or dismissed in the rush to raise self-esteem. Is there a variable that can work in synchrony with a wide variety of behaviors, influencing all of them, augmenting some (academic performance), changing the course of others (drug use)? Is there a variable that allows for a close reading of the external world with the level of accuracy that is needed to have this broad influence, the kind of variable that dedicated and hopeful self-esteem advocates thought they were getting with self-esteem?