This report, one of a series which will become chapters of a larger study entitled "A Study of Our Nation's Students" (see TM 000 145 and TM 000 182), concerns itself with total variation between students (T), within school variation (W), and among school variability (A) in the dependent variables (Expectations for Excellence, Attitude Towards Life, Educational Plans and Desires, Study Habits, and Achievement) which are accounted for by Family Social Background and Process measures as one moves from one geographic locale to another. It was found that the relative roles of Family Social Background (SB) and Process (PRCS) variables can be considered roughly similar since the unique role of PRCS greatly exceeds that of SB for both Expectations and Attitude Towards Life in all geographic regions. This same assertion holds to a lesser extent for Study Habits since there are metropolitan-nonmetropolitan differences at the third and twelfth grades. For Educational Plans and Achievement, however, the relative roles of SB and PRCS are not even roughly similar: the role of SB at both the T and A levels for these variables is usually most pronounced where social and economic stratification on the basis of race or ethnicity is greatest (viz., the South and to some extent the metropolitan North). It is suggested that the aggregate effect of allocating students with similar SB into the same schools is to make it more difficult for the schools to overcome the cumulative effect of SB. (DG)