These trends are based on happiness as measured with a survey question like: "Suppose the top of the ladder represents the best possible life for you and the bottom of the ladder the worst possible life. Where on this ladder do you feel you personally stand at the present time? - 10 -- 0".
These trends are based on happiness as measured with a survey question like: "Suppose the top of the ladder represents the best possible life for you and the bottom of the ladder the worst possible life. Where on this ladder do you feel you personally stand at the present time? - 10 -- 0".
This is an incredibly confusing chart and the website it comes from to explain it is no less confusing.