Image: Upside-down cake, Hollie at twigglebox.com
Is there such a thing as a team, a village, a community of equals? Generally not. The pattern of a leader and followers, or as the numbers of the unit increase, a small elite and a much larger mass of others appears universal.
French economist Thomas Piketty distinguishes three social strata – the top 10%, the middle 40% and the bottom 50%.
This chart of trends in income inequality from his very readable A Brief History of Equality (2022) illustrates the different fortunes of the lower and upper classes during the 20th century and the first decades of the 21st century.
Image: Thomas Piketty, 2022
Until 1980 the top 10% held a reducing share of the national income in both Europe and the US. Their share increased from 1980 to the present. Over the same period, the gradual increase from 1940 of the share accruing to the bottom 50% went into reverse after 1980. Again this was true for the lower classes in both Europe and the US.
When the hierarchy steepens – the few at the top gaining a larger share, the many at the bottom having less – there is an increase in violence.
A contemporary example is South Africa – a history of whites taking the opportunities to accumulate wealth has resulted in a society where a few have the majority of the country’s wealth. The top 1% of South African earners take home 20% of the nation’s income; the top 10% over half, or 65% of income. Homicide in South Africa is 42 per 100,000 – a very high level.
There is strong evidence that the relationship between high inequality and violence holds for countries, and also for the communities within countries. The United States has a high level of inequality and is an outlier (for wealthy countries) in its high level of homicide. Within the United States, states with a higher level of inequality have higher levels of homicide.
If there is a relationship between inequality and violence – is it a meaningful relationship or just one aspect of many factors that push violence around? The impact of “inequality” on violence seems to depend on the nature of the inequality. A 2020 review of 44 studies of European countries found “moderate” correlations (around .50) between economic inequality and homicide for Eastern European countries, but no effect in Western European societies.
The authors distinguished between relative and absolute inequality – in Western Europe, there is a safety net - even if you are at the bottom you still have access to the requirements for life. Your relative inequality is not a driver of violence. In Eastern Europe, if you are at the bottom you are without essential resources. Such absolute poverty appears to be a cause of violence.
This distinction between relative and absolute inequality was studied in the United States – comparing high homicide communities with no-homicide communities, matched on race. It was absolute inequality (lower median income, and in the US, a limited social safety net) that had the the most impact on the homicide rate. Relative inequality (relative income by state) was not irrelevant but of less weight.
Why would inequality, particularly inequality that reduces access to critical resources drive violence?
It is stressful not being able to access food, water, shelter and the other requirements for life. A trivial issue could trigger disproportionate violence in an individual experiencing this pressure.
Then there is our evolutionary history – male primates compete for mates. If you are a young male wired by evolution to compete, a world with limited resources is going to instigate more competition with local rivals – and as the stakes are raised, competition becomes more violent.
Inequality does not necessarily work in a simple and direct way. Poor people may be vulnerable to a range of stressors. Climate change is an increasingly significant issue, particularly for the poor. This could play out at the individual and also the social level. For example, heat inhibits the reception of serotonin (a neurotransmitter) and so limits inhibition – meaning those without aircon might be hot and hot-tempered, existing on more of a hair trigger.
At the macro level climate change results in more extreme weather, threatening the supply of clean water, resulting in more competition for this increasingly scarce resource. Communities can fight over access to water.
Lawrence Kuznar and Jeffrey Day put climate up against inequality in their relative effects on homicide rates; across 173 countries over the period 1960 to 2019. The “climate” was the mean temperature in these countries. Inequality was measured by the Gini coefficient (a measure of relative inequality – calculated in terms of the percentage of wealth held by each percentile of society) and absolute poverty (the percentage of the population below the country’s poverty line). Both Gini and absolute poverty were the standout predictors of homicide (.704 and .530 respectively – both “moderate” level correlations). The correlation with temperature was out of this moderate range, at .267 not irrelevant, but not as heavy-hitting.
But temperature correlated strongly with both Gini and absolute poverty. Countries that are closer to the equator are both hotter and generally where there are more poor people. Kuznar and Day considered social class (the three levels of poor, middle and wealthy) within the countries. For poor people, rises in temperature have a disproportionate effect on violence.
Economic inequality times climate change times other factors such as social class, and race-based or gender-based exclusion. For those who are squeezed out of opportunities – violence can seem worth the risk.