In the late 1860s, Charles Darwin proposed that being grossed out could have an evolutionary purpose. Disgust, he wrote, was inborn and involuntary, and it evolved to prevent our ancestors from eating spoiled food that might kill them. Darwin hypothesized that the early humans most prone to revulsion survived to pass on their genes, while the more nutritionally daring died off.

For many years afterward, though, scientists didn’t pay much attention to disgust. It wasn’t until the early 1990s, a decade when gameshows eagerly slimed contestants, that disgust garnered more attention in psychological and behavioral research. Since then, scientists have identified different types of disgust and have explored how they affect the way we behave.

The research shows