Next time you wonder why your Uncle Bob smoked, drank, and was overweight, yet managed to live to a healthy 100, try to find a picture of his boat and inquire about the neighbourhood in which he lived. How much did he earn? Even if your uncle lived in a socialized and developed state such as Canada, and was fairly well off to begin with, his level of health and his risk of mortality, were both affected by each additional dollar. The more money he made, the healthier he became. This held true, even after he achieved the level of income at which he could purchase ten times the required daily dose of vitamins, and have a personal masseuse. According to research, the reason for Uncle's wellbeing was the way his socio-economic status compared to that of others.
It is a well-known fact that socio-economic status plays a role in health and longevity but it is usually attributed to differences in quality of life and access to health care. If these were the only reasons, the rule of diminishing returns would prevail and would assure that no big improvements occur past a certain level of wealth. In fact, gross national product per capita is an important determinant of mortality in developing, but not developed, nations. In addition, countries with a more egalitarian distribution of income have a significant tendency towards lower mortality. What does not fit into this model, is the relationship between longevity and personal wealth. Studies show a linear increase at all income ranges. As a matter of fact, life expectancy in the fanciest neighbourhood in a developed country is probably higher than it is in the second fanciest neighbourhood in the same country. This improvement in health and longevity beyond the elimination of any physical deprivation has been attributed to the psychosocial effect of 'relative wealth'. The way our status in society compares to the status of others, even where only a subtle difference exists, has a profound impact on our level of stress, self-esteem, and social relations, all of which may be extremely important determinants of our health and longevity.
Public health researchers usually control their studies for sex, age, and social class, knowing that these factors impact on health and longevity. Unfortunately, not many studies have looked at the reasons for these effects. The difference between male and female average life spans seems to be biologically programmed (see "Geriatric Superstar Chicks and why they live longer"; G&A; October 2000) but it varies between different societies and over time. This suggests some degree of social shaping by the allocation of roles, risks, prestige and material resources to men and women. Similarly, a relationship between age and health is often due to biological aging, but it may also be due to the social role allocated to people of different age-sets in a particular society. For example, retirement is often followed by depression. Could delaying retirement age and changing our view of elderly's role in society from passive to active, delay aging and the onset of diseases? Could the recent, sudden onset of a high mortality rate in Russia be due to the change in economics that led to massive lay offs of 40 and 50 year olds from the workplace; employees who have virtually no hope of finding another job? Or, could this increase in mortality be a consequence of perestroika and glasnost, which brought Russians a realization of the stark contrast between their economic condition and that of people living in the West?
Perhaps the most important question to ask is at what stage in life these psychological determinants of good health and longevity make the biggest difference? Will a person who has always ranked low on the income scale be better off than a person who lost his or her rank later in life? Alternatively, is it crucial to be born in a good neighbourhood and be driven to school in a fancy car, or can these things be acquired later in life and still have a strong impact on longevity? Certainly, every day is important, and the famous saying "better later than never" definitely applies, but some studies suggest that long shadows are thrown forward from specific socio-economic circumstances. For example, a study that examined the contemporary differences in death rates among three adjacent towns in Lancashire--Nelson, Colne, and Burnley&emdash;traced them to the differences in the socio-economic circumstances of these towns in 1911. On the other hand, interviewed centenarians often describe their life as having been stressful and full of crises, particularly during the first several decades. Also, a study of elderly people with the highest sense of wellbeing, described in the national bestselling book "Pathfinders" by Gail Sheehy, found that passing through a series of life crises, and downfalls in self-esteem, is an essential component of achieving a strong sense of wellbeing later in life.
We are just starting to understand how, and when, our socio-economic status, and its associated sense of wellbeing, affect our longevity. In most part, longevity is still a matter of chance. As the rapidly aging population attracts more attention to this area, future discoveries should bring us a recipe for extending our lives to 120 and beyond.
References
- MacIntyre S. Journal of Public Health Medicine. 1994;16:53-9.
- Wilkinson RG. BMJ. 1992;304:165-8.
