NOTE ON SMELL: A VERT SHORT INTRODUCTION (2020)

A Very Short Introduction: Smell, by Matthew Cobb, OUP, 2020.

Smell, location, and memory:

as scientific research has shown, smells can indeed release memories in a very powerful way. For example, there is good evidence that richer memories are evoked when adults are presented with childhood-related odours than with childhood-related images. The key aspect of memory that seems to be unlocked by smell-including in Proust’s fictional example is not simply a memory of a particular fact or a particular event, but of things or emotions that were experienced in a particular place and at a particular time. These memories do not have to be pleasant. In people with post-traumatic stress disorder, smells that are associated with trauma, such as napalm or blood, can evoke powerful fear-related memories. (65-66)

The underlying basis of these kinds of effects is that in most animals, smells are used to immediately label experiences, so smell memories are often linked to places to where a particular event occurred. (66)

There is growing interest in the significance of the link between spatial memory and olfaction. A recent study of humans found that greater ability to identify odours was associated with better spatial memory, with frontal areas of the brain, which are involved in both olfactory processing and spatial learning, playing a particularly significant role. (67) 

In 2012, by Lucia Jacobs of the University of California suggested that in all animals a primary function of olfaction is navigation. (68)

(Sea-faring birds such as shearwaters) studies have shown that birds with damaged olfactory systems cannot find their way home, (69)

Fish such as salmon and lamprey will migrate across thousands of kilometres of ocean to find their way back to the stream where they hatched (69-70). 

…as the fish comes closer to the source of its home stream–perhaps even while out at sea-olfaction comes into play. (70)

Humans clearly use other sensory modalities for most navigation, but when we return somewhere -home. or a place we have not visited for some time–the smell is both evocative and comforting. (70) 

…as our ability to process odours is sculpted by our experience. (72) 

Brain imaging studies of humans support this interpretation, suggesting that the olfactory cortex is actively involved in memory processing, and is not simply a site where odours are identified. (73)

When we stop responding to a continuous smell – The evolutionary explanation for this effect, generally known as habituation or adaptation, would appear to be that a continuous stimulus no longer requires attention to be paid to it–it can be safely ignored. (73) 

In general, olfactory learning seems to be very rapid, unlike the situation with vision. For example, if people are presented with an image to learn, followed by several other images, the later stimuli interfere with recall of the target image. No such effect occurs with olfaction. Smells and flavours are involved in one of the strongest and least-investigated forms of learning-one-trial learning, where something happens just once, and is never forgotten. (75) 

A similarly strong form of learning occurs in animals such as sheep, where the mother rapidly learns the smell of its offspring and will generally reject attempts by any other lambs to suckle. This effect lies at the heart of the old shepherd’s trick for pairing a ewe whose lamb has died with an orphaned lamb—the skin of the dead animal is placed around the orphan. (76) 

Human babies can identify smells that are associated with food their mother has eaten when they were in the uterine fluid, or, after birth, through the odour of breast milk.

Odours learned in the uterus or at the breast are often associated with positive memories and can be recalled for years afterwards—they may well underlie the transmission of cultural food preferences and the strength of some of our attraction to particular foods. (76) 

The ecology of smell: 

Our planet depends on smell. Because so many organisms can produce and detect smells, it is often a key channel through which species interactions occur, allowing for mutual benefit or exploitation and determining the shape of the world we live in. Some interactions are commonplace and simple, others are unusual and highly complex; all reveal the essential role that smell plays in making the ecosystem the way it is. (78)

Smell in culture: 

The ancient tradition of burning scented woods, resins, or gums has a direct link to modern uses of fragrance- the word perfume’ has its origins in the Latin words ‘per’ and fumum’; meaning by smoke. In antiquity the production of incense and the extraction of resins became a major industry-the ancient Egyptians burned different kinds of incense three times a day as an offering to the sun (resin in the morning, myrrh at noon, and a blend in the evening). 95

Beliefs in supernatural beings and locations also involved smells. The ancient Egyptians believed that the gods sweated incense: by covering a corpse in sweet smelling unguent, the deceased would become closer to the gods. For the Greeks, the gods on Mount Olympus smelled of ambrosia and nectar, which they both ate and anointed themselves with. Christian writers generally described Hell as being full of foul smells, while according to Buddhist belief évil flesh-eating demons give off a rank odour. In a number of contemporary cultures evil spirits are still described as emitting a stench, and in many cultures the dead body is anointed with perfume to attract angels and repel devils. (96-97)

In the Middle East and Europe, the first recorded Perfumes were based on tree resins and gums; then the trend moved toward flowers, such as iris scents from Corinth, or marjoram from Cos. Perfumes based on animal products, such as the glands of musk deer, civet, and beavers, became fashionable in the late Middle Ages. (98) 

The politics of smell:

Throughout history people have consistently used smell descriptors to present particular social groups, in particular immigrants or racial minorities, as ‘other’. In the USA in the 19th century, Chinese migrants were accused of engaging in the foul-smelling sub-culture of opium smoking,’ while black slaves were alleged to ‘stink damnably’; even long after emancipation, (100) racist southerners claimed to be able to detect black people by smell. (101)

in Mein Kampf, Hitler complained of the smell of the Jews, while in 1992 the French Prime Minister Jacques Chirac notoriously complained about the ‘noise and smell’ supposedly produced by Arab immigrants. (101)

Travellers’ accounts often reveal an appalled fascination with the smells of other cultures. (101)

In Aromatics and the Soul, the Scottish surgeon Dan McKenzie quoted a fellow-countryman as saying, ‘The East is just a smell! It begins at Port Said; before adding his own take, inadvertently revealing the powerful impact left on him by the olfactory delights of the exotic East: ‘Who can ever forget the bazaar smells of India, the mingled must and fust with its background of garlic and strange vices, or the still more mysterious atmospheres of China with their deep suggestion of musk?’ (101)

One consistent form of discrimination that has been linked with odour is the oppression of women. In European cultures, witches were thought to smell, partly because they consorted with evil spirits and partly because they were women. There were three reasons why it was believed that prostitutes smelled –they were women, their sexual activity was associated with odours, and they often used perfume. Strikingly, one of the words for ‘prostitute’ in Romance languages -pute in French, puta in Spanish–has the same root as ‘putrid’. From the ancient Greeks to Christian theologians, many people (most of them men) have claimed to be able to detect whether a woman is a virgin on the basis of her smell. In many ancient religious ceremonies, the bride was heavily perfumed, both as a way of hiding her supposedly naturally foul odour and as a way of repelling evil spirits, djinns, or demons. This is just one example of the use in many cultures of fragrances to mark rites of passage-puberty, marriage, death, and so on. (103)

Despite our western prejudices, and the power of English terms like ‘to see’ meaning ‘to understand, human senses are not necessarily organized with vision at the top and smell at the bottom. Much of how we think and speak about smells is culturally contingent. (106)

The smell of culture:

Although scent is evidently significant in so many aspects of so many cultures, until recently historians and intellectuals paid little attention to a sense that, in western culture at least, was considered to be of lesser significance than vision and hearing. (106)

All that changed in a little more than a decade, with the publication of two landmark books. In 1982 the French historian Alain Corbin published an account of smell in 18th- and 19th-century France, translated in 1996 as The Foul and the Fragrant. Beginning in the 1780s, with the country on the brink of revolution, Corbin traced the links between public health and olfactory perception. Then in 1994, Constance Classen, David Howes, and Anthony Synnott published Aroma: The Cultural History of Smell, which explored smell across time and space using anthropological and cultural data as well as historical insights (some of the examples in this chapter are taken from this book). Since then, many researchers have explored the role of odours in specific parts of history and culture, such as the history of Christianity, the history of the perfume industry, or the link between smell and flavour in world cuisines. (107) 

Literature can provide a particularly powerful impression of how people view-or rather smell-the olfactory world. As the British academic John Sutherland has pointed out, the work of George Orwell often uses olfactory imagery, from the opening passages of 1984 (‘The hallway smelt of boiled cabbage and old rag mats), to the smell of a house concubine in Burmese Days (‘A mingled scent of sandalwood, garlic, coconut oil and the jasmine in her hair floated from her’). For Orwell, odour was an essential component in describing a scene and conveying atmosphere. Not all writers are so sensitive to scent- there are only a handful of references to odour in Hemingway’s writings, and only one in all of Jane Austen’s work (in Mansfield Park). (107-8)

In 19th-century Europe, novelists such as Zola, Balzac, and Dostoevsky all used olfactory imagery to convey place in their writings, while for the French novelist Huysmans and the poet Rimbaud, smells were linked to sensuous, sexual feelings.

In Aldous Huxley’s 1932 dystopian novel Brave New World, smell plays a primordial role-‘scent taps’ distribute fragrances, specific odours are used to condition the different genetically determined classes, contrasting the contrived and artificial world of civilization and the grubby, but infinitely more real world of the ‘savages! (108)

The Tale of Genji, written in 11th-century Japan by a noblewoman, Murasaki Shikibu, the fragrances used in the home (soradakimono) play a key role, acting as metaphors for the characters as well as highlighting emotions and the passing of the seasons. (109)

Throughout the 20th century, western culture became increasingly deodorized. In the 18th century, philosophers such as Kant and thinkers such as Buffon had argued that the sense of smell had something of the animal about it, and that it was not part of the finer, aesthetic sense that humans possess. This intellectual disdain for smell was soon accompanied by growing deodorization. (111)

There was a growing focus on personal hygiene, building on paranoid fears about having bad breath or body odour. There have even been repeated and misguided attempts to persuade women to use vaginal deodorants and scented sanitary products. (111)

Even where odours have become important in western society, this often relates to cleanliness. In the 1960s, manufacturers discovered that merely adding lemon fragrance to a detergent led customers to perceive it as more effective at cleaning, although the formula had not changed. (111)

Conclusion

Andreas Keller’ 2016 book Philosophy of Olfactory Perception, and Ann-Sophie Barwich’s 2020 Smellosophy both explore the similarities and differences between smell and the other senses, in particular what it is that we smell when we smell. Building on the work of the philosopher Clare Batty, they both conclude that we do not simply perceive chemical objects; instead we carry out a perceptual categorization based on chemical stimuli and heavily modulated by experience. 

This helps explain the magical aspect of smell, how odours are so often attached to meaning, and how the same odour can have very different meanings to different people. (124) 

In 1985, the American physician Lewis Thomas published a brief essay entitled ‘On Smell’, in which he poetically explored the smell of smoke. “Tobacco burning, coal smoke, wood-fire smoke, leaf smoke. Most of all, leaf smoke: The scent of leaf bonfires, he feared, with its aroma of comradeship, was endangered in the modern world; if it were to disappear, part of us would disappear, too. (125)