Why Smell is Our Most Overlooked Sense

September 20, 2026

AI Summary

5 min read

A 2016 survey of 16- to 30-year-olds found that a majority would rather give up their sense of smell than their mobile phone. That finding, cited by historian Dr. William Tullett at the top of this episode of Instant Genius, frames a conversation about why smell has been systematically devalued in modern life—and what we lose as a result. Tullett, author of Sniff: A History of Smell, argues that our olfactory neglect is not natural but learned, and that the past two centuries have seen a dramatic, often invisible transformation of the chemical world we breathe.

The Chemocene: How We Changed the Air

Tullett introduces the term chemocene to describe the period since the Industrial Revolution, during which humans have introduced vast numbers of new synthetic chemicals into the environment. This is a specific dimension of the better-known Anthropocene, focusing on the intentional and unintentional manipulation of airborne molecules. One striking example: in the 1940s, after a deadly school gas explosion, U.S. utility companies began adding mercaptan—the sulfurous molecule that gives rotting meat its smell—to natural gas so leaks could be detected. An unintended consequence was that vultures and coyotes began congregating at pipeline leaks, mistaking the smell for carrion. The chemocene is thus a story of engineered odors with ecological side effects, from industri

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What you'll learn

1 (01:50) **Introduction: The Overlooked Sense** - Host Jason Goodger introduces the topic and guest Dr. William Tullett, historian at the University of York, author of *Sniff: A History of Smells*.
2 (03:08) **Personal Origins: Why a Historian Chose Smell** - Dr. Tullett explains his path to studying the history of smell, rooted in childhood visits to smelly industrial and military museums.
3 (04:45) **The "Chemocene": A New Chemical Era** - Dr. Tullett introduces the term "chemocene" to describe how humans have intentionally and unintentionally altered the world's chemical and odor landscape since the Industrial Revolution.
4 (06:58) **How Historians Reconstruct Past Smells** - The host asks how Dr. Tullett researches what the past actually smelled like, given the lack of direct sensory records.
5 (08:53) **Scent, Memory, and the Home: The Case of Pine** - The discussion turns to the deep history of scenting homes, using the personal example of a grandmother's house smelling of bleach.
6 (11:11) **Smell, Class, and Inequality** - Dr. Tullett explains how smell has been a marker of class, from fashionable perfumes to the forced exposure of the poor to foul odors.
7 (14:24) **Quantifying Smell: The Cinema Experiment and the Olfactometer** - The host highlights a German study where a mass spectrometer analyzed cinema odors to guess a film's age rating based on stress molecules from the audience.

+ Full timestamped outline available in the app

Show Notes

Though often thought of as the poor cousin to our other senses, our sense of smell has played a key role in human life since its very beginnings. It helps us to determine whether certain foods are safe to eat, protects us from environmental dangers such as fire, mould and toxic chemicals, and has even been weaponised for use as a form of racial or economic discrimination. Without it, the world would be a vastly different place.

In this episode we’re joined by Dr William Tullett, an historian and author based at the University of York, to talk about his new book, Sniff – A History of Smells.

He tells us how advances in technology over the last several centuries have resulted in significant impacts on the odours that pervade our everyday lives, how many of us would rather give up our sense of smell than our phones, and explains how we can all reconnect with our sense of smell to widen our experience of the world we live in.

Take your curiosity further with a subscription to BBC Science Focus magazine. Every issue is packed with fascinating insights into the science behind everyday life, the latest breakthroughs and expert analysis, delivered straight to your door. Receive an extra £5 when you subscribe using the code SF5OFF, (minimum spend £20, see full terms and conditions on our website).

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