Inequality can hurt our economies, societies, and even our bodies. In a new article in the Scientific American, Robert M. Sapolsky of Stanford University draws on several medical studies to show just how inequality is hurting health outcomes.

He notes that across the world the widening gap between the rich and the poor has resulted in greater health and social problems. One study shows that as inequality has increased in OECD countries, a combined health index, which captures life expectancy, infant mortality and a range of other health issues, has become worse. This trend is true even in countries with universal healthcare, a system designed to equalize health outcomes.

According to Sapolsky, while poverty in itself hurts health, poverty among plenty (inequality) hurts health more. A broad range of research has shown that life in societies with disparities between rich and poor creates constant social and psychological stress for the poor that grinds down human bodies and brains.

For instance, studies have shown that inequality-induced stress affects the prefrontal cortex of the brain, critical for long-term planning and impulse control. This makes people more impulsive and less likely to choose long-term health over immediate pleasure.

This explains why people under stress tend to drink and smoke more.

Another common effect of stress is chronic inflammation in the human body which damages molecules and increases the risks of heart diseases. Stress by social circumstances can also have more deep-rooted effects by affecting human DNA, fraying chromosomes and causing premature aging.

For Sapolsky, the body of evidence linking inequality to health is strong enough to warrant serious attention. India, grappling with its own inequality problems, should be especially concerned.

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