Quality of Life Over the Past Four Decades: The Public Rates Their Present, Past and Mean ratings on 0 to 10 scale
But part of the methodological elegance of this famous battery, developed about a half-century ago by Princeton University psychologist Hadley Cantril, is that respondents aren’t asked, directly, to evaluate their own progress in life. Rather, they are asked to imagine a ladder with ten steps, with 10 representing the highest possible quality of life for them and zero the lowest. Then they’re asked which step of the ladder they feel they’re on at the present time; which step they were on five years ago; and finally, which step they expect to be on five years from now. People aren’t asked to make “better” or “worse” judgments. They’re simply asked to assign numerical ratings to their life at three different points in time.
For example, in the 2006 Pew survey (taken this summer), Americans on average gave a 6.1 score to their lives five years ago; a 6.8 score to their present quality of life; and a 7.8 score to the lives they expect to be leading five years from now. That adds up an aggregate average of 1.7 rating points worth of forward progress between five years ago and five years hence.
Quality of Life Over the Past Four Decades:  | The Public Rates Their Present, Past and  | Future  | Mean ratings on 0 to 10 scale  | 10.0  | 9.5  | 9.0  | 8.5  | 5 years from now  | .8  | 8.0  | 7.5  | 7.0  | Present life  | 6.5  | 6.0  | 5.5  | 5 years ago  | 5.0  | 1964 1970 1976 1982 1988 1994 2000 2006  | Source: Research Surveys from 1964 to 1985 by Gallup; 1987 to 2006 by Pew  | Research Surveys Center. 