The textbook refers to a single question that was used to measure happiness. The question was: ""Imagine a ladder with steps numbered from 0 at the bottom to 10 at the top. The top of the ladder represents the best possible life for you and the bottom of the ladder represents the worst possible life for you. On which step of the ladder would you say you personally stand at this time?"" What is the name of this single question that was used to measure happiness?

Cantril Ladder

Explanation:

Cantril ladder approach was developed by Hadley Cantril. The approach is a method of assessing the well being of individuals. The cantril scale is represented by an imaginary ladder with steps numbered from 1 to 10 wherein each step denotes a happiness level.

For example, level one would relate to poor well being i.e the case of individual being least happy whereas level 10 would represent highest satisfaction in life and happiness.

As per the research conducted across the globe, the cantril scale of well being and happiness correlated really well with the income of the respondents indicating, that well being and happiness are directly related to an individual's income level.