In conventional terms the standard of living has become practically synonymous with a material standard, and consequently the concept has most often been equated with and measured by per capita income. Yet it can be interpreted much more broadly to encompass the psychological and biological dimensions of human existence (i.e., the quality of life in all of its manifestations). Distinguishing among these components of well-being would not add much that is conceptually meaningful to our understanding of the past if they all correlated positively and perfectly with one another. But recent empirical evidence has tended to show the importance of not conflating them into one concept.

Historians have begun to explore ways to illuminate this issue from another perspective, namely by considering the biological standard of living as an equally valid measurement of human well-being (Komlos 1989). One approach has been to study the health of historical populations, though this avenue is obviously limited by the scanty systematic evidence at our disposal (Riley and Alter 1986). Another approach has been to consider mortality an integral component of welfare and, in fact, to incorporate mortality into the conventional index of the material standard of living (Williamson 1981, 1982; Davin 1988). Yet this attempt to collapse the biological and material standards of living into a single index is vexed by the inherent difficulty of gauging the monetary value of human life.

Still another promising approach, and one with an abundant evidential basis from the seventeenth century onward, is anthropometric history, meaning the analysis of secular changes in human height, weight, and weight for height (Tanner 1981; Fogel 1987; Komlos 1987; Ward 1987; Riggs 1988; Cuff 1989; Floud and Wachter 1989).