Since I was a kid, I’ve had a good sniffer. I grew up reading Scratch n Sniff books, which I read over and over again. Some of those smells I still detect in my memory today. I also would go in the candle aisle and smell every single scent on the shelf while my mom shopped. As I got older, I knew which smells were offensive and not to sniff them. These days, I still like my candles and fragrant body lotions, and the keen sense of smell remains.
For over 150 years, we have been led to believe that humans have a poor sense of smell compared to other mammals. A study published in Science explains that there is no evidence that our sniffers are any worse than others. This paper removes centuries of unproven information. A sensory neuroscientist from Rutgers, John McGann, who normally studies mice, wanted to test humans in comparison. Humans have 400 genes to detect odor while mice have 1,000. However, when mice struggled to differentiate between two odors, humans had no trouble telling them apart.
A nineteenth century medical book with the work of Paul Broca, a prominent neurosurgeon from France, said that human free will came at the expense of being able to smell less well than other animals. This conclusion came from comparing the size of the frontal lobe and olfactory bulb in humans to other mammals. Humans have larger frontal lobes and smaller olfactory bulbs. Broca divided animals into those whose main sense was smell (osmatics) and those who use other senses. A later researcher in 1890 divided the non-osmatics into those that can’t smell at all and are poor smellers (humans). American neurologist CJ Herrick stated that human olfactory organs are “greatly reduced”. Sigmund Freud claimed that smell is diminished in humans, and those who enjoy smells are animalistic and likely to suffer from sexual disorders.
Recent studies are showing how robust human sense of smell is. A 2014 study found that humans can distinguish between one trillion distinct smells. Other studies have shown that humans can track scent trails outdoors as well as dogs. McGann concludes that human sense of smell is excellent and detect all volatile chemicals larger than a few atoms. Scientists are looking to find odorants we can’t smell.
Netburn, Deborah. “The human nose has been underrated for 150 years, but science is setting the record straight.” Science. Los Angeles Times, 11 May 2017. Web. 14 May 2017.