February 17, 2018

LJ Talks to Rachel Herz

By Mary Ann Hughes

Proustian scholars, foodies, and popular psychology fiends alike would be wise to seek out Rachel Herz’s eminently readable The Scent of Desire: Discovering Our Enigmatic Sense of Smell (October, Morrow). Drawing on the latest research, the visiting professor to Brown University breaks down the powerful connection between our nose and emotions—one that can influence our choice in a signature scent and romantic partners. Longtime LJ reviewer Mary Ann Hughes spoke to Herz to get to the bottom of our olfactory system.

LJ: The title of your book sounds like a romance novel. Why did you choose it?

Smell is the sense that is most closely linked to our emotions, our passions. Scents themselves also can trigger extremely potent emotional associations and states. Scents are also very important in sexual attraction. In sum, our sense of smell is the sense of desire, and scents themselves induce desire. I wanted to capture those concepts and, of course, a sexy title helps to turn heads.

LJ: Like you, I like the smell of skunk. But when I took a survey of my coworkers, 12 said that it was a horrible smell, and four said they neither liked it nor hated it. Why do people react so strongly to odors?

Our sense of smell is intimately and immediately connected to emotion. The part of the brain that processes odors is directly linked to the part of the brain that processes emotions and motivations; none of our other sensory systems has this special and privileged connection.

The purpose of the sense of smell is to tell us what to approach (what we like) and what to avoid (what we dislike) based on the meaning that the odor has taken on. Scents that elicit neutral responses only do so because they are not meaningful to the smeller. My guess is that your office mates who were indifferent to the scent of skunk did not have a meaningful connection to the smell one way or the other.

Skunk is a bit of a special case, however, because it depends on how close you are to the spray. If you are up close and personal, you are going to get hit with a blast of trigeminally irritating chemicals as well as the scent of skunk, and this will make even me turn away. Many scents trigger the trigeminal system, which is a tactile system in the face. It is what gives menthol a cool feeling, cinnamon a warm one, and what makes ammonia feel burning. We are inherently repelled from strong trigeminal irritation because it hurts! Those who consider repulsion to skunk scent “obvious” probably know its sting. It is also possible that due to individual difference in olfactory receptor expression, we don’t all smell the same chemical brew that a skunk emits. Some of us may be more or less sensitive to certain elements of its bouquet than others and the difference in how “strong” the scent is to us may play a role.

LJ: You talk about the importance of scent for falling in love. Has anyone studied the fate of Internet-based relationships? Does that phenomenon of the partner just not smelling right become a factor for some of these couples when they finally meet?

This is an interesting question. In the traditional dating scenario, you would find out about the person’s social and physical qualities and there be able to assess how much you liked his or her smell. In the Internet scenario, this can’t happen, so it will depend on what state of romance you are in when you finally do meet up. If you have already fallen in love, then the clean and natural scent of your new paramour is going to be wonderful no matter what the biological compatibility between the two of you is. This is because a positive emotional association has already been made—his or her scent has taken on the meaning of your love for him or her. If you aren’t in that stage yet, you may still be able to use the scent as a useful signal for whether, or how much, you are attracted to him or her and hence know whether he or she is biologically “right” or “wrong” for you.

LJ: You argue that multiple chemical sensitivities syndromes, such as Gulf War syndrome or sick building syndrome, are psychological, not physiological, phenomena. Do you think there is a relationship between odors and illness? What about allergies?

There is certainly a connection between odors and illness. Various diseases change our body chemistry and change the odors that our bodies produce. In the case of highly contagious diseases, recognizing this different/warning smell could be very important in helping you keep away from the person emitting it and hence catching the disease.

Allergies don’t seem to have much to do with scent per se, as they are triggered by other biological and chemical factors like pollen, spores, fungi, etc. However, people can be induced to feeling like they are having an allergic reaction to a scent if they are “afraid” of the scent, are highly suggestible, or have otherwise acquired allergy-like responses to the scent based on circumstances.

LJ: As an expert on the psychology of smell, you’ve done many media interviews. What events cause the television networks to call you up?

I get the most calls around Thanksgiving, Christmas, and Valentine’s Day. At Thanksgiving and Christmas, people want to understand the memory connections and special emotional meanings of specific aromas like pumpkin pie, pine, cinnamon, mint, and so on. For Valentine’s Day, it’s about the connection between scent and sexual attraction.

LJ: What don’t we know about the sense of smell?

There are many mysteries that remain. The most important one from my perspective is to understand fully all the steps along the pathway from how a chemical “out there” goes to being responded to with disgust or desire in our minds and bodies. Another important problem is understanding the connection between genetic differences in olfactory receptor expression and how that may influence odor perception and individual differences in our predisposition to like or dislike certain smells, like skunk.

We know you like skunk smell. What are some other favorites?

I love the scent of stargazer lilies and lilac. I love a number of food smells like garlic, basil, and barbecuing meat. I also love certain familiar smells associated with special people and my dog.