Founder of the World Database of Happiness, Ruut Veenhoven explains the pitfalls of studying this essentially subjective topic – and who can benefit from the results.
Technologist: How do scholars define happiness?
Ruut Veenhoven: Studying life satisfaction can be traced from early Greek philosophy (Democritus) right up to the 18th century (Jeremy Bentham). But back then most philosophers used the term in the wider sense of “leading a good life”, where “good” meant morally sound. They emphasized moral qualities rather than the subjective enjoyment that scientists focus on today. The term happiness surfaced recently, both because of its increased relevance in our contemporary multiple-choice society and because it is measurable.
T. Science deals with the objective, but happiness is essentially subjective. Can you trust conclusions based on self-reported survey data?
R.V. Because happiness is a subjective phenomenon, it is best measured with subjective self-reports. It’s like headaches: though much simpler, they are also best measured subjectively, for instance by scoring on a visual scale. Subjective self-reports are useful and precise: self-reported health appears to be a better predictor of longevity than objective health screenings.
T. How exactly can you design studies to reveal these feelings?
R.V. The most common are large-scale surveys among the general population in a country in which some 2,000 randomly selected citizens answer hundreds of questions on many topics, one of which is how satisfied they are with their life as a whole, “taking all together”, expressed on a scale of 10. You can assess the correctness of the results, for example by asking the same question using different words, asking the same question a couple of weeks later or asking close friends or family to estimate how the respondent would answer. All these tests show that people typically understand the question and that their answers can be trusted.
T. How well do we understand the factors influencing levels of happiness?
R.V. We have a good idea what influences happiness on an individual as well as a national level. Of course, measures of happiness are subject to measurement error like any other measure. But if we look at two countries, around 80% of the difference can be explained by objective country characteristics such as wealth, the strength of communities or the quality of local TV.
I estimate that an additional 10% of the difference lies in objective conditions on which we have no quantitative data. Another 5% of the difference could be in measurement errors of the described country characteristics. That leaves us with about 5% of the variance due to inaccurate self-reports, like haphazard responses, overstatements of happiness and extreme responses.
T. What impact can these surveys have, beyond newspaper headlines?
R.V. Measuring happiness or life-satisfaction can help policymakers make the right choices on behalf of their populations. This development is just beginning: Great Britain is one of the first nations to use measurements of happiness to evaluate changes in policy. Measuring happiness might also reveal conflicts before they explode. During the five years leading up to the Arab Spring, the national happiness in Egypt went down 33%, even though GDP was rising steadily.
This is possible only because the field of happiness research has finally reached scientific maturity with a consensus of definitions, good methods for measuring happiness and a lot of robust data.