The Face Hole Series
Interesting Facts about Your Sense of Smell
And The Reason Perfumers Put Cat Pee in Perfume
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Did you know you can smell fear? Beyond the stench of smelly armpits, terrified sweat contains pheromones that trigger the parts of our brains that sense fear. We can smell other emotions too: disgust, happiness, and even sexual arousal. All in, we can sense over one trillion different odors, even if we aren’t aware of them. We can even smell teen spirit.
Smell is evolutionarily one of our oldest senses. Its acuity peaks in our mid-teens, and women have a stronger sense of smell than men.
Although it seems logical that our noses do the smelling, they are merely the face hole that allows the odors in. Smell happens in the cluster of nerves we call the olfactory nerve. Those roughly 12 million nerve endings are located between our eyes, upstream from the cribriform plate, a thin bone perforated with tiny holes. Odor molecules get up there in one of two ways: by breathing them in through our noses or up the back of our noses when we chew food. (Odor makes up nearly 75% of flavor.) Once there, the odor molecules dissolve in the mucus, and a scent is born.
When the olfactory or smell nerve is stimulated, it sends a signal not only to the olfactory bulb, which processes the scent. It also passes it on to the limbic system, which controls our mood, emotion, and behavior. Because of this connection, we easily create memories through smell, especially when accompanied by an emotion. In fact, smell is the sense most intimately tied to memory.
As we smell our way through the world, we are constantly sensitized to certain odors. We remember the bliss of holiday family gatherings when we smell cinnamon and cloves. The scent of old books invokes quiet libraries and fascination. A whiff of fresh cut grass reminds us of the joy of summertime. Depending on the circumstances, our reactions can also evolve to match the associated memory. Imagine you are a funeral director. Roses may smell like death.
Some odors are pleasant regardless of association or cultural background. One study showed that the most pleasant smell of all is vanilla, followed by peach-smelling ethyl butyrate. The least pleasant…
