"The Scent of Desire" | Intriguing analysis of smell

"The Scent of Desire: Discovering Our Enigmatic Sense of Smell"

by Rachel Herz

Morrow, 288 pp., $24.95

What better praise to give a nonfiction book than to say it will transform the way its readers think about its subject. In Rachel Herz's case, the subject is our sense of smell.

Herz, a visiting professor of psychiatry and human behavior at Brown University, is one of the world's leading researchers in this young field, and one of the field's better explainers, variously turning up in The New Yorker or NPR or U.S. News & World Report to share her findings.

In "The Scent of Desire," she starts with the notion of inherently "bad" smells. They don't exist, she argues, offering as evidence, among other things, her own love of skunk essence, or infants' acceptance — even love? — of the smell of feces, or our military's failure to develop an all-purpose stink bomb, even in using "U.S. Army issue latrine scent."

Likewise, she debunks the notion of any inherently "healthful" smells in, say, aromatherapy. She doesn't discount its use in a relaxing environment — say, in a hot bath or on a massage table — but adds: "there is no scientific evidence in humans that by inhaling sandalwood aroma the essence of sandalwood is detectable in the bloodstream — which it would have to be if it were producing a pharmacological effect."

Our response to a smell, she says, is largely associative, whether it's our immersion in certain smells in the womb (as early as 12 weeks), positive or negative experiences with certain aromas, or the biases of our culture.

Then there's the romantic, long-held idea that we are attracted to the scent of our lover. It's not imagined, Herz says, but rather built into our DNA. She says that the unique cluster of genes comprising a person's immune system manifests itself in that person's equally unique odorprint. If someone's odorprint is dissimilar to ours, it offers the greatest complementarity for our offsprings' health, and therefore is the most appealing.

Equally telling, though, Herz says that birth-control pills, in mimicking pregnancy, might cause a woman to desire an odorprint less than ideal for her immunological makeup. The ramifications of that are a little mind-boggling.

Dementia in older persons? Herz says that in some cases, it might instead be simply evidence of malnutrition, which comes from a deterioration of the smell system, and thus of any desire for food, in advancing years.

Reading through Herz's book is not slog-free — she is, at heart, a researcher, so the narrative brakes for some pretty dry case studies throughout.

And the field does seem a little too new and small for readers to believe Herz's conclusions should be considered definitive.

Still, Herz's discussion of this hugely important field of study is a captivating one, and readers can be thankful she's brought us up to speed on a subject that will be intriguing, dare we say fun, to watch in coming years.