Cantril's Self-Anchoring Scale (1965)
Princeton researcher Hadley Cantril developed the 'Cantril Ladder'—a 0-10 scale asking respondents to rate their lives from worst to best possible. Working with Lloyd Free through the Institute for International Social Research, he collected cross-national happiness data decades before the WVS.
The Cantril Ladder became the standard instrument for measuring life satisfaction, enabling systematic cross-country comparison.
The scale remains the primary metric used by the Gallup World Poll and the World Happiness Report, directly enabling the research that the WVS and later studies built upon.
The measurement tools developed by Cantril made the WVS's 40-year tracking project technically possible. Without standardized scales, comparing happiness across time and cultures would be impossible.
