I have had a day filled with scents. You might even call some of them bad smells. Today was hot and humid and I was stuck in traffic behind a dump truck. It smelled terrible. The smell made me feel angry and even a little nauseous. I went out of my way not to follow that stinky truck. When I got home, I sat on my back porch next to a giant lily. It smelled wonderful. It made me feel happy and calm and even a little bit wistful. Looking back at my two radically different reactions made me wonder if I’m overly sensitive or is everyone so deeply affected by scents.
Certainly bad scents put us off and we find good ones pleasant – they might even inspire us to shop or make love – but my reaction felt a little bit over the top today. It was. Here’s why: heat and humidity. In order for a stinky scent to travel through the air to your nose, it has to be in a gaseous state. The molecules in humid air trap those gases. Heat increases molecular volatility – those stinky scents move faster to your nose.
Certain scents, let’s call them pleasant ones, elicit muscle-relaxing, calming effects. Some hotels use such scents to welcome guests into their lobby; some realtors bake chocolate chip cookies in the kitchen of a home they are about to show. The Social Issues Research Center tells us why in The Smell Report:
Our olfactory receptors are directly connected to the limbic system, the most ancient and primitive part of the brain, which is thought to be the seat of emotion. Smell sensations are relayed to the cortex, where ‘cognitive’ recognition occurs, only after the deepest parts of our brains have been stimulated. Thus, by the time we correctly name a particular scent as, for example, ‘vanilla’ , the scent has already activated the limbic system [which controls basic emotions (fear, pleasure, anger) and drives (hunger, sex, dominance, nurturing)], triggering more deep-seated emotional responses.
The positive emotional effects of pleasant fragrances also affect our perceptions of other people. In experiments, subjects exposed to pleasant fragrances tend to give higher ‘attractiveness ratings’ to people in photographs, although some recent studies have shown that these effects are only significant where there is some ambiguity in the pictures…Unpleasant smells can also affect our perceptions and evaluations. In one study, the presence of an unpleasant odour led subjects not only to give lower ratings to photographed individuals, but also to judge paintings as less professional.
Some ‘bad’ scents trigger migraines. Some experts believe that these odors cause our blood vessels to swell and dilate, which stimulates the nerves in the brain associated with head pain. Much like a distracting noise, a bad smell can cause you to perform poorly on a test. Think of it this way: as our olfactory senses evolved, humans became more acutely aware of bad smells (sabertooth tiger) as a means of self-preservation. Instead of ‘fight or flight’ our modern reaction is simply anger and anxiety (that damned dump truck).
I think I’ll keep some Blossom Water in the car for next time.