We live in societies where some people are richer than others – though the extent of wealth inequality varies greatly around the world.
In general, it’s sad but true that poor people suffer more diseases. Within a given country almost all physical and mental illnesses are more common amongst the poor, although this isn’t always true between countries.
So if a certain disease is more common in rich people within a country, that’s big news because it suggests that something unusual is going on. Autism spectrum disorders (ASDs) have long been known to show this pattern, at least in some countries, but this has often been thought to be a product of diagnostic ascertainment bias. Maybe richer and better-educated parents are more likely to have access to services that can diagnose autism. This is a serious issue because autism often goes undiagnosed and diagnosis is rarely clear-cut.
An important new ...
