Happiness among American men and women reaches its estimated minimum at approximately ages 49 and 45 respectively.
To design effective social and economic policies, policymakers need a measure of individuals' "well-being." Yet while such things as real Gross Domestic Product, lifespan, height, and the incidence of cancer can be counted, it is a much more complicated task to objectively quantify psychological well-being and happiness. For example, recent statistical research has shown that countries like Denmark, Ireland, and the Netherlands are particularly happy, while nations such as Germany, Italy, and Portugal are less happy. However, one could argue that words such as "happiness" or "satisfaction" cannot be communicated unambiguously and in exactly the same way across countries, so it is not easy to know whether such cross-national well-being patterns are believable.
In Hypertension and Happiness across Nations (NBER Working Paper No. 12934), co-authors David Blanchflower and Andrew Oswald draw upon data on 15,000 randomly sampled individuals from 16 countries, and on other larger samples, to develop a measure of well-being related to the incidence of high blood pressure. They find evidence to suggest that happier nations report fewer blood-pressure problems. And, this seems to be true regardless of the dataset used in the analysis. Nor do the results seem to be caused by differing numbers of physicians across countries.
The authors' findings in this study rest on three assumptions: first, that it is reasonable to treat their survey evidence on high-blood-pressure problems as a proxy for true measures of hypertension. Second, that people report high blood pressure in a more objective way than they report levels of happiness. Third, that the patterns they find are not merely the product of something special for this particular sample of nations.
Of course, it is possible that the results of this study are not valid because an inherently cheery nation will be optimistic about everything. However, it is hard to believe that someone told by their doctor that they have high blood pressure would have an incentive to conceal or misreport that. For researchers in general, the attraction of a blood-pressure question in surveys is that it relies on medical facts given to the individual, and thus seems valuably different in character from conventional subjective questions about well-being. Furthermore, the authors point out that while psychological health cannot be measured easily, it is nonetheless high in Denmark and low in East Germany. While happiness and hypertension are linked, more research remains needed on how such connections may operate.
In Is Well-being U-Shaped over the Life Cycle? (NBER Working Paper No.12935), Blanchflower and Oswald study happiness and life-satisfaction data for half a million Americans and Europeans. They draw two main conclusions from the data: first, that psychological well-being moves along a U-shaped curve as we age. Second, that there are important differences in the reported happiness levels of different age groups.
The authors suggest that reported well-being is U-shaped in age. Happiness among American men and women reaches its estimated minimum at approximately ages 49 and 45 respectively. Among European men and women, life satisfaction levels are at their minimum at ages 44 at 43 respectively. The authors emphasize that, because their research controls for many other influences upon happiness and life satisfaction -- including income, education, and marriage -- these results should be read as truly describing well-being.
By definition, the authors caution, their study has one important limitation. The international datasets that they use do not follow the same individuals over the years. They also note that what truly causes the U-shaped curve in human well-being, and the noticeable regularity of its mathematical shape in different parts of the industrialized world, is not currently known. Potential answers, some more plausible than others, include the following: first, that individuals learn to adapt to their strengths and weaknesses, and in mid-life quell the unfeasible aspirations of their youth. Second, that cheerful people live systematically longer than those who are miserable, and that the U-shape somehow traces out, in part, a selection effect. Third, that a kind of comparison process is occurring - for example, I may have seen school-friends die and as a result eventually come to value my blessings during my remaining years. There are likely to be other explanations for the U-shaped effect, too.
-- Les Picker