One of the perceived truisms in education has been that student background characteristics are the most important determinants of student achievement. Indeed, as discussed in Chapter 1, this was one of the primary conclusions of the studies by Coleman and colleagues (1966) and by Jencks and colleagues (1972). It has also been assumed that, implicitly or explicitly, these background characteristics are largely impervious to change. Popular books such as Bias in Mental Testing by Arthur Jensen (1980) and The Bell Curve by Richard Heurnstein and Charles Murray (1994) have made elaborate statistical cases that background characteristics, particularly intelligence, are genetically based and can be changed little by schooling. In contrast, I believe that the research clearly shows that even some of most negative aspects of a student's background can be mediated by school-based interventions.

In Chapter 1, I supplied evidence that schools generally account for only 20 percent of the variance in student achievement and that student background characteristics account for the other 80 percent. But what if a school could do something about those background characteristics? In the next three chapters, we explore which student background factors schools can address and what they might do about them. What, then, are the student background characteristics that influence academic achievement?

Student-Level Factors: A Comparison Across Researchers