What is “disgust”? Molly Young, a journalist with The New York Times, considers the evolutionary and social uses of this “universal aspect of life” to identify the impact of disgust in its physical, psychological and linguistic manifestations.

Young explains the different forms of disgust, analyzing how the reactions they elicit play out in the body and mind, and why it is in many ways cultural. She explains how disgust shapes our behavior, technology, relationships and even political leanings. It’s behind everyday purity rites; the reason we use toilet paper, wash our hands and hold cutlery; it has shadowed the rules that have governed emotion in every culture throughout time.

Charles Darwin, the scholar William Ian Miller, the research psychologist Paul Rozin and the philosopher Aurel Kolnai, among the many others who felt compelled, Young explained, to investigate this most primal emotion.

This story was written by Molly Young and recorded by Audm. To hear more audio stories from publications like The New York Times, download Audm for iPhone or Android.