Richard G. Wilkinson

Socioeconomic determinants of health. Health inequalities: relative or absolute material standards?

That mortality in developed countries is affected more by relative than absolute living standards is shown by three pieces of evidence. Firstly, mortality is related more closely to relative income within countries than to differences in absolute income between them. Secondly, national mortality rates tend to be lowest in countries that have smaller income differences and thus have lower levels of relative deprivation. Thirdly, most of the long term rise in life expectancy seems unrelated to long term economic growth rates. Although both material and social influences contribute to inequalities in health, the importance of relative standards implies that psychosocial pathways may be particularly influential. During the 1980s income differences widened more rapidly in Britain than in other countries; almost a quarter of the population now lives in relative poverty. The effects of higher levels of relative deprivation and lower social cohesion may already be visible in mortality trends among young adults. A “feel bad” factor in the health divide? TONY WALLIS The existence of wide-and widening-socioeconomic differences in health shows how extraordinarily sensitive health remains to socioeconomic circumstances. Twofold, threefold, or even fourfold differences in mortality have been reported within Britain, depending largely on the social classification used.1 2 3 This series will illustrate some of the most important mechanisms involved in the generation of these differences. Fundamental to understanding the causes of these differences in health is the distinction between the effects of relative and absolute living standards. Socioeconomic gradients in health are simultaneously an association with social position and with different material circumstances, both of which have implications for health-but which is more important in terms of causality? Is the health disadvantage of the least well off part of the population mainly a reflection of the direct physiological effects of lower absolute material standards (of bad …

Psychosocial and material pathways in the relation between income and health: a response to Lynch et al

Much of the debate on health inequalities has centred on the damage done by poverty. However, evidence suggests that health is also related to inequality. Firstly, as the Whitehall studies of British civil servants show, there is a gradient in health among those who are not poor, indicating that the higher the socioeconomic position, the lower the morbidity and mortality.1–4 Whole population samples show that this gradient runs right across societies and that its magnitude varies between societies and over time. 5 6 Although absolute mortality has been falling in Britain, inequalities in mortality have increased. 7 8 Secondly, despite the health gradient within societies, there is little relation between average income (gross domestic product per capita) and life expectancy in rich countries. This suggests that absolute material standards are not, in themselves, the key. Thirdly, there is a strong relation between mortality and income inequalities. People living in countries with greater income inequality have a shorter life expectancy.9–11 Furthermore, a similar relation has been found for geographical areas within countries.12–15 #### Summary points Economic and social circumstances affect health through the physiological effects of their emotional and social meanings and the direct effects of material circumstances Material conditions do not adequately explain health inequalities in rich countries The relation between smaller inequalities in income and better population health reflects increased psychosocial wellbeing In rich countries wellbeing is more closely related to relative income than absolute income Social dominance, inequality, autonomy, and the quality of social relations have an impact on psychosocial wellbeing and are among the most powerful explanations for the pattern of population health in rich countries These observations support our argument that there are psychosocial pathways associated with relative disadvantage which act in addition to the direct effects of absolute material …

Health, hierarchy, and social anxiety.

Abstract: This paper suggests that the main reasons why populations with narrower income differences tend to have lower mortality rates are to be found in the psychosocial impact of low social status. There is now substantial evidence showing that where income differences are greater, violence tends to be more common, people are less likely to trust each other, and social relations are less cohesive. The growing impression that social cohesion is beneficial to health may be less a reflection of its direct effects than of its role as a marker for the underlying psychological pain of low social status. Low social status affects patterns of violence, disrespect, shame, poor social relations, and depression. In its implications for feelings of inferiority and insecurity, it interacts with other powerful health variables such as poor emotional attachment in early childhood and patterns of friendship and social support. Causal pathways are likely to center on the influence that the quality of social relations has on neuroendocrine pathways.

Income inequality and health: A causal review

There is a very large literature examining income inequality in relation to health. Early reviews came to different interpretations of the evidence, though a large majority of studies reported that health tended to be worse in more unequal societies. More recent studies, not included in those reviews, provide substantial new evidence. Our purpose in this paper is to assess whether or not wider income differences play a causal role leading to worse health. We conducted a literature review within an epidemiological causal framework and inferred the likelihood of a causal relationship between income inequality and health (including violence) by considering the evidence as a whole. The body of evidence strongly suggests that income inequality affects population health and wellbeing. The major causal criteria of temporality, biological plausibility, consistency and lack of alternative explanations are well supported. Of the small minority of studies which find no association, most can be explained by income inequality being measured at an inappropriate scale, the inclusion of mediating variables as controls, the use of subjective rather than objective measures of health, or follow up periods which are too short. The evidence that large income differences have damaging health and social consequences is strong and in most countries inequality is increasing. Narrowing the gap will improve the health and wellbeing of populations.

Social organization, stress, and health

© Oxford University Press, 2014. This chapter takes up the issue of biological plausibility. It addresses two issues: First, is it plausible that the organization of work, degree of social isolation, and sense of control over life could affect the likelihood of developing and dying from chronic diseases such as diabetes and cardiovascular disease? The various biological pathways that can plausibly change the risk of developing major disease are discussed. The second issue is more complicated - do any of the plausible biological pathways actually operate; that is, not could they cause disease, but do they? The evidence on this is incomplete and is an important topic for current and future research, but it is sufficiently suggestive to point to hypotheses for testing.

Wider income gaps, wider waistbands? An ecological study of obesity and income inequality

Objectives: To see if obesity, deaths from diabetes, and daily calorie intake are associated with income inequality among developed countries. Design: Ecological study of 21 developed countries. Countries: Countries were eligible for inclusion if they were among the top 50 countries with the highest gross national income per capita by purchasing power parity in 2002, had a population over 3 million, and had available data on income inequality and outcome measures. Main outcome measures: Percentage of obese (body mass index >30) adult men and women, diabetes mortality rates, and calorie consumption per capita per day. Results: Adjusting for gross national per capita income, income inequality was positively correlated with the percentage of obese men (r = 0.48, p = 0.03), the percentage of obese women (r = 0.62, p = 0.003), diabetes mortality rates per 1 million people (r = 0.46, p = 0.04), and average calories per capita per day (r = 0.50, p = 0.02). Correlations were stronger if analyses were weighted for population size. The effect of income inequality on female obesity was independent of average calorie intake. Conclusions: Obesity, diabetes mortality, and calorie consumption were associated with income inequality in developed countries. Increased nutritional problems may be a consequence of the psychosocial impact of living in a more hierarchical society.

Mortality, the Social Environment, Crime and Violence

Starting out from the relationship between income equality and indicators of social cohesion and social trust, this paper explores the social processes which might account for the relationship between greater income equality and lower population mortality rates. We note that: homicide shows an even closer relationship to income inequality than does mortality from all other causes combined; there are several reports that homicide rates are particularly closely related to all cause mortality; and that there is a growing body of research on crime in relation to social disorganisation. We use US state level data to examine the relationships between various categories of income inequality, median state income, social trust and mortality. The data suggest that violent crime, but not property crime, is closely related to income inequality, social trust and mortality rates, excluding homicide. The second half of the paper is devoted to literature on the antecedents of violence. Feeling shamed, humiliated and disrespected seem to be central to the picture and are plausibly related to the way in which wider income differences are likely to mean more people are denied access to traditional sources of status and respect. We suggest that these aspects of low social status may be central to the psychosocial processes linking inequality, violence, social cohesion and mortality.

People like us: ethnic group density effects on health

Studies examining the effects of neighbourhood characteristics have reported what has been called a ‘group density’ effect on health, such that members of low status minority communities living in an area with a higher proportion of their own racial or ethnic group tend to have better health than those who live in areas with a lower proportion. In this paper we survey published research on ethnic group density and health with the aim of stimulating further research. We situate the research question in the context of contemporary social epidemiology and provide a narrative review of studies of ethnic density and health. We go on to discuss processes which may underlie ethnic density effects, and highlight gaps in the literature and opportunities for further research. Although first recognised in studies of mental illness, ‘group density’ effects on physical health have been shown more recently. Generally, given individual material circumstances, living in a poorer area is associated with worse health. Members of ethnic minorities who live in areas where there are few like themselves are likely to be materially better off, and living in better neighbourhoods, than those who live in areas with a higher concentration. However, through the eyes of the majority community, they may be made more aware of belonging to a low status minority group, and the psychosocial effects of stigma may offset any advantage. If the psychological effects of stigma are sometimes powerful enough to override material advantage, this may have implications for our understanding of how low social status affects health more generally. As well as highlighting the importance of low social status, cultural isolation and social support to health and quality of life, this paper shows how an understanding of group density effects also has something to offer to our understanding of issues of prejudice, segregation, assimilation and integration in diverse societies.

Child wellbeing and income inequality in rich societies: ecological cross sectional study

Objectives To examine associations between child wellbeing and material living standards (average income), the scale of differentiation in social status (income inequality), and social exclusion (children in relative poverty) in rich developed societies. Design Ecological, cross sectional studies. Setting Cross national comparisons of 23 rich countries; cross state comparisons within the United States. Population Children and young people. Main outcome measures The Unicef index of child wellbeing and its components for rich countries; eight comparable measures for the US states and District of Columbia (teenage births, juvenile homicides, infant mortality, low birth weight, educational performance, dropping out of high school, overweight, mental health problems). Results The overall index of child wellbeing was negatively correlated with income inequality (r=−0.64, P=0.001) and percentage of children in relative poverty (r=−0.67, P=0.001) but not with average income (r=0.15, P=0.50). Many more indicators of child wellbeing were associated with income inequality or children in relative poverty, or both, than with average incomes. Among the US states and District of Columbia all indicators were significantly worse in more unequal states. Only teenage birth rates and the proportion of children dropping out of high school were lower in richer states. Conclusions Improvements in child wellbeing in rich societies may depend more on reductions in inequality than on further economic growth.

National mortality rates : the impact of inequality ?

Although health is closely associated with income differences within each country there is, at best, only a weak link between national mortality rates and average income among the developed countries. On the other hand, there is evidence of a strong relationship between national mortality rates and the scale of income differences within each society. These three elements are coherent if health is affected less by changes in absolute material standards across affluent populations than it is by relative income or the scale of income differences and the resulting sense of disadvantage within each society. Rather than socioeconomic mortality differentials representing a distribution around given national average mortality rates, it is likely that the degree of income inequality indicates the burden of relative deprivation on national mortality rates.