We exist with odours all around us from the food we prepare.

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22 PERSONAL CARE November 2011

Murray Hunter – University Malaysia Perlis (UniMAP)FRAGRANCES

We exist with odours all around us fromthe food we prepare, buy and eat, theenvironment we live within, and theoffices, houses, apartments, toilets,animals, and people we come across dayin, day out. We make judgements aboutwhat we smell, where odour certainlyinfluences the proximity of ourrelationships with others. Body odours tellus a lot about a person’s disposition.Odour influenced public policy aboutsewage and rubbish collection and wasone of the main reasons the world’spopulation is no longer subject to greatplagues that hit earlier societies throughthe ages.

The ability to smell was one of ourmost primal senses, which was importantin helping us find food, give warnings ofdanger, and identify spoiled food, etc.Odour also masked our body odours andgave us a sense of pleasure andsensuality. The importance of odour hasdeclined in our age as most city buildingsand homes are relatively sterile or neutralin their odour. The majority of odours wecome across in the urban environmentare commercially produced in the bakery,from an air freshener, through the airconditioning system, or from a colleaguewearing an eau de toilette. Relatively fewpeople now directly appreciate the odourof new mown hay, the changing odour ofhanging jasmine on a trellis, or the smellof ozone after a thunder storm.

We must first understand some of thebasic concepts about the physiology andcognitive aspects of our olfactoryarchitecture to understand the myths andrealities about the psychology of smell.

Our olfactory architectureHow the olfactory system works has beenwell explained by other literature and thiswill only be briefly recanted here. Whenwe sniff something or just breathe inthrough our nose, we also inhale aromaticmolecules with the air. These moleculesare bundled together in their millions anddiffuse from their concentration accordingto Graham’s law (the rate of effusion of agas is inversely proportional to the square

root of the mass of particles) towardsareas of lesser concentration where theolfactory mucosa, a membrane with amucous surface contains the olfactoryreceptors at the top of the nasal cavity.Odour molecules are slightly water solubleand can pass through the lipid richmucous that immerse the receptors at theepithelium surface and interact witholfactory receptor neurons. The odorantsbind with the olfactory receptor neuronsand change the shape of proteins,creating ion flows which pass along theaxons of the olfactory nerve through thecribriform plate or skull to reach theolfactory bulb (alomeruli) which is anoutcropping from the inferior (bottom)side of the pre-frontal cortex of the brain.

The olfactory mucosa also containsanother sensory system made up oftrigeminal nerve receptors which are ableto sense tactile pressure, pain, andtemperature variation. They also existaround the mouth and eyes. Thesereceptors can sense hot, cold, tingling,and irritability, in a similar manner to theskin. It is through these receptors that wecan sense the coldness of menthol andthe warmth of methyl salicylate. Up to

70% of our odour perception travelsthrough this system of receptors.1

As mentioned above, aromaticmolecules must possess some watersolubility characteristics, have a highvapour pressure, and have the ability todissolve in fat. Molecules above amolecular weight of 300 cannot passthrough the mucous membrane, thus ourinability to smell any molecule with amolecular weight more than that. Eachneuron has only one type of receptor, ofwhich there are about 1,000 differenttypes. Even aromatic molecules withslightly different chemical structuresactivate different types of receptors, sooctanal smells like orange will bedifferentiated from the similar octanalacids which are sweeter. Larger amountsof aromatic molecules tend to bind awider variety of receptors than do smalleramounts of the same molecule. This mayexplain why concentrated amounts ofindole tend to smell horrible but lowerconcentrations smell somewhat sweet andflorally. Although the rate of odour flowdoes not affect the intensity of the odour,a concentrated odour molecule thatattaches to most receptors may prevent

The myths and realities of odour psychology

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the receptors sensing other odourmolecules bringing on a condition that aperfumer calls olfactory fatigue, where thesense of smell is lost to other odours for ashort period of time until the receptors arefree again.

It is estimated that a human candifferentiate between 5,000-10,000odours.2 This is probably possible throughsome method of combinational recognitionand processing scheme to encode theidentities of different odours, and a singleodour may be recognisable by a singlereceptor and different odourants arerecognised through different combinationsof receptors.3

However, just as a person can recogniseslurred vowels spoken by someone or readsentences that are spelt incorrectly, thebrain through the process of categoricalperception simplifies our perception loadsinto convenient odour groups orcategories.4 As we know, similarlystructured molecules do not necessarilysmell the same, and differently structuredmolecules may smell the same, thus it isnot easy to relate smell with thephysiochemical structure to our sense ofsmell. Our categorisation of odours actuallyputs limits and biases upon how we definethem through the various classificationsystems that have been developed over theyears. It is only when brilliant innovationsare recognised that our restrictedvocabularies are expanded. Fragrance wascategorised into nicely restrictivecompartments until Martin Gras wrote histwo seminal papers The Overdose and TheOverdose II that we could see beyond thecompartmental definitions we devised forourselves.5

Unlike the receptors in our sight andhearing, olfactory receptors regenerate.

Cognitive processingWhat happens next is much moreinteresting and relevant to the myths andrealities of odour psychology. Sensoryinformation from the olfactory bulb isdespatched to two different locationswithin the brain.

The first is the limbic cortex deep withinthe middle of the brain, responsible for ouremotions, moods, feelings, sexual arousal,and long term memory retrieval. It is alsoresponsible for the feelings of “high” orintoxication we feel from recreationaldrugs. The limbic cortex is very closelyconnected to the pre-frontal lobes, whichare responsible for our creativity andimagination.6 Both these areas, the pre-frontal lobes and limbic cortex, play a veryimportant role in our motivations, and thusbehaviour.

The second area that signals are sent tois the hypothalamus which is responsiblefor the restoration of the physicalmetabolism through balancing hormones,blood glucose, and regulating temperature.

In women, the hypothalamus synchronisesthe levels of oestrus which controlsmenstruation. In animals, thehypothalamus regulates sexual drive fromreceiving certain pheromonal stimuli, but todate this process has not been found inhumans. Pheromones tend to be odourlesschemicals to humans but in animalsinfluence behaviour in powerful ways. It isquestionable whether our olfactory systemwould detect them. The hypothalamus alsoreacts to blood-borne stimuli, which maybe an important issue in aromatherapy,discussed a little later.

Due to the fact that our olfactory systemconnects directly to the emotional part ofour brain, one would expect odour to evokeprimal behaviour in humans. This is not thecase, in fact the brain does not know whatany odour signifies until we learn what it isand through our life experiences connectparticular odours to our feelings andemotions. The meaning of fragrance is asocially constructed reality; just like welearn the meanings of words, sounds, andthings we see and touch.7

Just like everything else, odours are not encoded with any meaning at theperception level. Odours are compared tothe “database” of our life experienceswithin our long term memory to providemeaning. Prior to this socialisation, allodours are inherently neutral in beingpleasant or unpleasant and have noattached emotional or other meaningembedded within our memory. Thus, anymeaning attached to any odour is theresult of our experiences and socialisation,requiring associations between perception,the odour, the event, and our feelings andemotions about it. But due to the fact thatodour perception information flows directlyto the limbic cortex, odour acts very quickly,

Figure 1: The olfactory interpretation process from input to response.

Chempaka flowers (Michelia champaca) hasan odour quite popular in the West, but to aMalay it symbolises death.

Olfactory input

Other inputssight, hearing, touch and taste

Symbolism: Product/strategy attributes, advertising,

themes, symbols, logos, colours, social attitudes and acceptance etc.

Sensation: a sensory message transmission

of information about the environment to the brain

Transduction: convert physical energy into neural

Meaning:imagination, emotions,

fantasy and belief

To sensory receptors

Cognitive processing Memory retrieval

BehaviourShared meaning and fantasy

Interpretation

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prompting stimuli to retrieve memory andemotions.

The following examples show odour is acultural phenomenon. First, the odour ofchilli; to some this means somethingdelicious to crave for, Thai somtam forexample. To others, the smell of chilli (ormaybe more correctly, the associatedodours around a chilli based dish) acts as awarning: “Don’t eat this or I will sufferbadly”. Again a bakery in a shopping mallgives an Australian a sense of feeling good,but the smell of a good curry will give aSouth Asian that same sense of feelinggood and anticipation (however, with theglobalisation and move into cross-culturalfusion cuisines, culinary signals now workacross many cultures, rather than theculture that the dish originated from).Chempaka flowers have a deep rich, sweetfloral odour reminiscent of one of the finestfragrances, quite popular in the West, butto a Malay it symbolises death, as the treeis common in graveyards. Food and odourare social constructions.

We can see this socialisation in all thethings we smell. Lemon did not give theidea of “fresh” until we socially accepted itas so. Remember the heavy advertisingduring the 1960s about lemon cleaningpower. We had to learn that. Thesemeanings probably came from our earlierassociations with the environment and

socially spread across the globe, as newwonderments from other lands, just as teaand coffee were brought back from thenew world to the old world of Europehundreds of years ago through theexpeditionary vogues of the Portuguese,Spanish, Dutch, French, and Englishgalleons of the times.

Odour was not sensual in the beginning;it had to be connected to sensuality.8 Theearliest known use of fragrance for sensualpurposes was the use of fragrant plantsinfused into olive and sesame oils forointments around 7,000 BC. Around3,000 BC the Egyptians used myrrh fortheir pleasure and by 700 BC, Athens wasa mercantile trading centre for perfumes.9

Aristocrats during the first century AD inRome heavily imported frankincense andmyrrh. Nero was famous for his scentedparties – as no “orgy” was completewithout perfume.10

The commercialisation of fragranceResearch into cognitive olfaction draggedbehind the other senses until relativelyrecently.11 We cannot predict whatfragrance will be popular and sell well, asthere are no universal rules or secrets thatcan be employed because thepsychological effects depend so much onacquired associations. Remember Lt. Col.

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Figure 2: Product/strategy attribute profile.

Product/strategyattributes

Features Benefits

Intangiblebenefits

Tangiblebenefits

Signalattributes

Channels

Generalimpression

Spiritualimpression

Tactile andsensory

impression

Impact

Odour profile

Substantively

Ingredients(according to theme)

Efficacy

Efficacyaccording to theme

Pleasant and lastingfragrance

Romance

Health andwellbeing

Caring

Security

Lifestyleassociation

Concern

Strength

Performance

Variant

Indicator of use

Life status

Freshness

Association

Local

International

Consumerdemographics

Mainstream or specialised

Form ofpromotion and

association apt to

product theme

Bill Killgrove of the air cavalry in the filmApocalypse Now, played by Robert Duvall,where he said in that famous beachlanding scene: “Do you smell that son,napalm son...I love the smell of napalm inthe morning...it smells...like....victory”.Odour is associated with values andaspirations, dreams and hopes. Odour isour fantasy and brings memories, personalmeanings, and feelings to the present.Odour is a nexus between the past, presentand future, linking them in powerful waysthat strongly influence the way peoplebehave in the future.

Why is this so important? Because weare influenced by our internal cognitiveprocesses, our memory and the outsideworld. Product creation requiresimagination to construct the customerorientations necessary.12,13 But the essenceof opportunity also requires consumers tobe imaginative, by bringing the externalinternally; to imagine what it would be liketo live at Sanctuary Cove on the Gold Costof Queensland, Australia, to imagine what itwould be like consuming a Ferrero RocherChocolate, to imagine climbing the EiffelTower in Paris, France, to imagine skiing atBoulder, Colorado during the winterholidays, to imagine owning an AppleiPhone, to imagine wearing BeyoncePerfume, to imagine the benefits to thecommunity a cup of Starbucks Coffeewould have, and how that raffle ticketwould assist the fight against cancer.Imagination is an aid to practical thinkingand opens the door to making purchasingdecisions.14 All our hopes, enlightenment,fears, and desires come from imagination.Brands are able to give consumers a senseof identity and enrich their life experiences,a shared imagination or fantasy. Togetherthe internal and external determine ourbehaviour, which is what marketing isabout. Figure 1 schematises the olfactoryinterpretation process from input toresponse, highlighting the role of fragrancein the marketing picture.

Internally we are influenced by ourselectivity, what we put our attention upon,which is influenced by our motivations,emotions, curiosity, values, cognitive, style,experience, personality, and interests.Externally, we are attracted/distracted bythe symbols, meaning, peer acceptances,messages aimed at various characteristicsof our ego like “satisfying needs andwants”, “sensual pleasure”, ”statussymbols”, “feeling good”, “being attractiveto others”, “gaining admiration fromothers”, “power”, “fun”, “happiness”, etc.Product promoters try to create the imagesand symbols that we will connect to ouralter ego and stimulate our imaginationthat has emotional strength to influenceour behaviour. And it is when companies

Multifunctional Cosmetic Additives

The artof science

successfully develop a shared imaginationstimulated by the themes, images,symbols, and personalities they project intotheir products, that are supported by theattributes of the product, market successis within the firm’s grasp. Fragrance is oneof the most powerful of these attributes.Try walking past a Dunkin Donut storewhen they are making a fresh batch ofdonuts. Fragrance combined with the shoplayout, position, colours used, combine tocreate an influence that is hard to resist.Fragrance, when combined with the othersenses, is extremely powerful,15 andcompanies know that. They create theimages and symbols and try to embedthem within us.

So is it the odour that sells the product,or other factors? Somewhere, one hopes,the answer lies within the continuum ofthese factors. Without the other factors afragrance is not immediately meaningful.The role of fragrance is to help differentiatethe product from its competitors.16

Fragrance in cosmetics and personal careproducts helps to render a productdistinguishable to the consumer in the vastarray of products on the shelf. In highlydeveloped markets, cosmetics, toiletriesand household products have reached astage where differentiation of primaryproduct image builders (advertising,promotion, price, packaging) have becomedifficult to develop as a source ofcompetitive advantage over competingproducts. Secondary image builders(fragrance, colour, types of ingredientsused in the product) took on more

importance in the 80s and 90s.17 Nowthemes are the great productdifferentiators, of which fragrance is theprompting mechanism. Figure 2 shows aproduct/strategy attribute profile where bothprimary and secondary product attributesare merged to create the product’s imagewith consumers. If all the product attributestogether can successfully espouse atheme, then a very powerful productidentity will be created. Look at finefragrance marketing campaigns wediscussed above as an example.

We have been socially conditioned toassociate odour to particular emotions,stimulation of intense pleasure, efficacy,freshness, sensuality, gentleness, andsuccess, etc. This link between odour andemotion is so powerful that very oldmemories and vivid emotions can beevoked instantaneously like experiencesthat occurred yesterday.18 Fragrances aresignals which can communicate messagesto consumers.

Thus the product message must beconverted into an odour. The perfumer mustbe aware of the issues involved, wherevarious fragrance families can aid insuggesting gentleness, freshness, strength,and efficacy in a product. For example somecitrus notes can convey the concept offresh, which is important in dishwashingliquids, while laundry products may requiregentle, efficacy or freshness-efficacy,depending upon the target consumer. Ashampoo may require fresh and gentle orfresh and efficacy depending upon themessage the perfumer wants to get across

Figure 3: Psychological grid of fragrance interpretation.19

Fresh Efficacy

Gentle Strong

Citrus Family

Mint

Floral Family

Ambergris

OzonicMedicated

Coniferous

Spicy Metallic

Peach

Powdery

Balsamic

Musk

Woody

Agrestic

Green

Peppery

to the consumer. These are supported by,and also support the other product attributesthe company associates with its product.

Figure 3 shows a grid where differentfragrance families are plotted within thefour sectors denoting gentleness,freshness, strength and efficacy. Someindividual notes from within a family candiffer in their message from the rest of thefamily, as is the example in the floral familywhere some are gentle, others fresh, andothers signifying strength and efficacy.These are all subjective classificationswhich are culturally sensitive.

Myths and realitiesSo what are the myths and realities ofodour psychology? What does it mean tothe industry and the future of fragrance asan integral part of the product attributes?How does what we know about cognitiveolfactory processing alter what we believeabout odour psychology? Some of thesequestions are answered by merging thedisciplines of human physiology, cognitivescience, aromatic chemistry, psychology,and marketing as we have in this paper,which are summarised in Table 1.

w Note: A version of this article was first publishedby the Australian Society of Cosmetic Chemists.

PPCC

References1 Ohloff G. Scent and fragrance. Berlin &

Heidelberg, Springer-Verlag, 1994.2 Gilbert AN. What the nose knows: the science

of scent in everyday life. New York: HarperPerennial, 2008.

3 Malnic B, Hirono J, Sato T, Buck LB.Combinational receptor codes for odors. Cell 1999; 96 (5): 713-23.

4 Reed SK. Cognition: Theory and Applications7th edn. Belmont CA: Thomson Wadsworth,2007.

5 Gras M. The Overdose. Perfumer & Flavorist1990; 15 (6): 25-8.

6 Csikszentmihalyi M. Creativity: flow and thepsychology of discovery and invention. New York: Harper-Collins, 1996.

7 Herz RS, Beland SL, Hellerstein M. Changingodor hedonic perception through emotionalassociations in humans. Int J Comp Psychol2004; 17: 315-39.

8 Jellinek P. The Practice of Perfumery. London:Leonard Hill, 1954.

9 Poucher WA. Poucher’s perfumes, cosmetics and soaps, Vol 2: the production, manufactureand application of perfumes 9th edn. London:Chapman & Hall, 1993.

10 Burr C. The Emperor of Scent: A true story ofperfume and obsession. New York: Random-House, 2003.

11 Herz R. The scent of desire: discovering our

enigmatic sense of smell. New York: HarperPerennial, 2007.

12 Gabay J. Imaginative marketing. London: TeachYourself Books, 1998.

13 Postma P. The new marketing era: marketing tothe imagination in a technology driven world.New York: McGraw-Hill, 1998.

14 Brown S, Patterson A. Figments for sales:marketing, imagination and the artisticimperative. In: Brown S, Patterson A eds.Imagining marketing: art, aesthetics and theavant-garde. London: Routledge, 2000.

15 Wilson DA, Stevenson RJ. Learning to smell:olfactory perception from neurobiology tobehavior. Baltimore: The John Hopkins UniversityPress, 2006.

16 Miles JM. An integrated approach to fragrances andformulation. Drug Cosmet Ind 1989; March, p26.

17 Hunter M. The use of natural fragrances incosmetics: should it be considered? Cosmetics,Aerosols & Toiletries in Australia 1996; 10 (3): 47.

18 Goldemburg RL. Aromatherapy for wellbeing. Drug Cosmet Ind 1991; Sept, p42.

19 Hunter M. Essential oils: art, science, industry,agriculture & entrepreneurship: a focus on theAsia-Pacific. New York: Nova Science Publishers,2009.

20 Herz R (2009). Aromatherapy facts and fictions:a scientific analysis of olfactory effects on mood,physiology and behavior. Int J Neurosci 2009;119: 263-90.

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Table 1: What are the myths and realities of odour psychology?

w To our present knowledge there are noaromatic materials that act as pheromoneson humans. Human pheromones areconsidered a myth. Fragrance does notphysiologically sexually arouse people; ratherany effects are from emotional associationand suggestion based on society’s currentset of behaviours. The most importantsexual aid we have is our imagination.

w Any fragrance creation will not be deemednovel without reference to the acceptanceof peers and customers. Commercialsuccess rather than the beauty of theproduct itself is the criteria by which anyodour is deemed novel in the fragranceindustry. Therefore fragrance creativity has acompetitive streak through it incommerciality, taking it further away fromthe concept of art. This is contrary to whatthe “new age” natural perfumers aspire.

w Odour does stimulate behaviour through ouremotions but in specific situational waysthat may be unique to every individual,remember the Killgrove example. Due toolfactory signals going directly to the limbiccortex which also controls emotions,fragrance will always have an importantinfluence on humans that fragrance andcosmetic companies will continue to try toexploit. Perfumery will remain a multi-billiondollar commercially orientated industry.

w Just like any language is limited by itsvocabulary, fragrance novelty is limitedby the fragrance vocabulary andclassification systems of the day.Novelty only increases its bounds whenperfumers go beyond currentclassifications and create the need fornew classifications. In probability withthe commercial orientations of theindustry, breaking the bounds will be atruly rare occurrence that will happenonly a couple of times each century.

w Aromatherapy efficacy through inhalingodours depends upon the ability of theodour to connect with moods andemotions to be effective.20 As we areaware, the connection of odours toemotions is a social construction andthe way aromatherapy throughinhalation works is through the beliefs ofthe user. There is nothing wrong withthat because it is what one believes thatis reality, and the correlation betweenmoods and wellbeing is a strong one.The relationship between odour and thehypothalamus is still unexplored territoryat this point of time. Aromatherapythrough infusion and massage has theability to push more essential oils intothe body through digestion and skinabsorption respectively.

w Our olfactory receptors cannot distinguishbetween natural and synthetic odoursbecause, to all intents and purposes, themolecule is exactly the same, except forsome isomer differences. Theappreciation of something natural is avalue rather than being somethingphysiologically different. There is nothingwrong with having values about things,because without values the humanspecies would not survive.

w Odour is situational to people, places,and contexts. Due to the influences upon(air conditions, fatigue, concentrations,etc.), and architecture of the olfactorysystem, different people in differentcircumstances will smell an odourdifferently. This is also cultural specific,and contextual to different situations, i.e.,camphor is medicinal to Australians butused to embalm corpses in Malaysia,thus creating different imagery in people.

w Finally, a great perfumer must haveimagination, curiosity, the emotions ofinterest and passion, olfactory sensitivity,a prior knowledge of odourous materialsand their characteristics, knowledge ofoutstanding fragrance creations, practicalexperience, time, patience andperseverance, be an artist, psychologist,and marketing practitioner, all in one.