Abstract
Patterns of family size, family stability, and timing of family formation characteristic of Mexican-Americans are contrasted with those of Japanese-Americans, and consequences of their demographic differences for group achievement are explored. Mexican-Americans are found to have a demographic system marked by young ages at marriage, young ages at beginning of childbearing, high rates of reproduction, and high rates of marital instability. Japanese-Americans display just the opposite pattern of behavior on each of these variables. Using existing research on determinants of individual achievement, reasons are then suggested why the demographic environment encountered by Japanese-American youth is more conducive to educational and economic achievement than is that encountered by Mexican-American youth.