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The Forgotten Sense: The Fascinating Science of Smell with a Mind-Expanding Perspective, Discover the Power of Your Nose
James Nestor’s Breath meets Mary Roach’s Gulp in a fascinating tour of our most essential sense for perceiving the world around us—and the story of how it became our most neglected.
Smelling is one of the most natural things we do. We take over 20,000 breaths a day, interacting with a host of scents with each one. Smell is also one of our most sensitive and refined senses; few other mammals surpass our ability to perceive scents in the animal kingdom. Yet, as the millions of people who lost their sense of smell during the COVID-19 pandemic can attest, we too often overlook its role in our overall health.
Now, one of the world’s leading researchers on smell Jonas Olofsson reveals the fascinating science behind this forgotten sense. Drawing from cutting-edge original research, Olofsson reveals not only that the human sense of smell is extraordinarily sensitive, but how it engages our brain’s full capacity. In fact, olfaction begins not in the nose, but in the brain, even before an odor’s molecules reach our smell receptors. Our memories, personalities, preferences, and expectations shape the way we interact with scents, with profound implications for how we perceive the world around us.
With playful curiosity and a breadth of scientific interest across neuroscience, psychology, linguistics, and even literature, The Forgotten Sense reveals the wonders of smell, and all that we lose in neglecting it. We meet ancient philosophers who prized smell as well as the nineteenth-century scholars who associated it with “beastly” instincts and charted its devaluation for over a century. Olofsson untangles the role of smell in human evolution and answers the question of why two people can interpret the same smell differently. And, crucially, we see smell as the intellectual exercise that it is, with invaluable insight into how we might train our brains to strengthen and even regain our sense of smell after illness.
For readers of Bill Bryson and Steven Pinker, The Forgotten Sense reveals the depths of the most understudied function of human life.
Smelling is one of the most natural things we do. We take over 20,000 breaths a day, interacting with a host of scents with each one. Smell is also one of our most sensitive and refined senses; few other mammals surpass our ability to perceive scents in the animal kingdom. Yet, as the millions of people who lost their sense of smell during the COVID-19 pandemic can attest, we too often overlook its role in our overall health.
Now, one of the world’s leading researchers on smell Jonas Olofsson reveals the fascinating science behind this forgotten sense. Drawing from cutting-edge original research, Olofsson reveals not only that the human sense of smell is extraordinarily sensitive, but how it engages our brain’s full capacity. In fact, olfaction begins not in the nose, but in the brain, even before an odor’s molecules reach our smell receptors. Our memories, personalities, preferences, and expectations shape the way we interact with scents, with profound implications for how we perceive the world around us.
With playful curiosity and a breadth of scientific interest across neuroscience, psychology, linguistics, and even literature, The Forgotten Sense reveals the wonders of smell, and all that we lose in neglecting it. We meet ancient philosophers who prized smell as well as the nineteenth-century scholars who associated it with “beastly” instincts and charted its devaluation for over a century. Olofsson untangles the role of smell in human evolution and answers the question of why two people can interpret the same smell differently. And, crucially, we see smell as the intellectual exercise that it is, with invaluable insight into how we might train our brains to strengthen and even regain our sense of smell after illness.
For readers of Bill Bryson and Steven Pinker, The Forgotten Sense reveals the depths of the most understudied function of human life.
215 pages, Kindle Edition
Published January 7, 2025
38 people are currently reading
648 people want to read
About the author
Jonas Olofsson
9 books10 followersI am a research professor at Stockholm University and an author. For information about my research, see: https://www.su.se/english/profiles/jo...
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Displaying 1 - 30 of 36 reviews
January 25, 2025
Excellent insight (sense pun intended) into a the history and power of smell that have stuck with me; the concept of smelling through your throat in particular really blew my mind, There is so much more nuance to uncover about what seems like a more mundane sense, and it was fascinating to learn how much of our "common knowledge" about smell is at best misleading or since disproven, and at worst empirically wrong. Highly recommend to anyone with a nasal cavity.
February 25, 2025
This is my favorite type of non-fiction: just enough facts, statistics, & research blended with non-academic stories & examples. Both allow me to understand enough to see the issues & consider future treatments & possibilities, without being overwhelmed.
July 26, 2025
The Forgotten Sense is a fascinating exploration of the often-overlooked sense of smell and its profound impact on our lives. The book dive into the biological, psychological, and cultural significance of smell, uncovering its deep connection to memory, emotion, and even survival.
The author explains how smell functions at both molecular and neurological levels, showing how closely it is intertwined with taste and how our brain’s interpretation of scent can be influenced by anticipation and experience. There are interesting segues into how smell helps us detect danger—whether it’s spoiled food or toxic substances—making it an essential part of our evolutionary defense system.
Beyond the science, the book touches on unexpected connections, such as how attitudes toward smell can reflect broader social and political traits, including openness or authoritarian tendencies. It also examines the history of smell in medicine, showing how olfactory cues ("The miasma theory") were once central to diagnoses before the rise of modern diagnostics.
What makes smell particularly intriguing, the book argues, is how deeply it's shaped by habit and culture—what smells pleasant or offensive is often learned, not innate. This book is a reminder that our noses are doing far more than we usually acknowledge and how it can be trained and honed to our advantage just like wine sommeliers. Parts of the book do get repetitive and I wish it was edited a bit better, but still a worthy read.
The author explains how smell functions at both molecular and neurological levels, showing how closely it is intertwined with taste and how our brain’s interpretation of scent can be influenced by anticipation and experience. There are interesting segues into how smell helps us detect danger—whether it’s spoiled food or toxic substances—making it an essential part of our evolutionary defense system.
Beyond the science, the book touches on unexpected connections, such as how attitudes toward smell can reflect broader social and political traits, including openness or authoritarian tendencies. It also examines the history of smell in medicine, showing how olfactory cues ("The miasma theory") were once central to diagnoses before the rise of modern diagnostics.
What makes smell particularly intriguing, the book argues, is how deeply it's shaped by habit and culture—what smells pleasant or offensive is often learned, not innate. This book is a reminder that our noses are doing far more than we usually acknowledge and how it can be trained and honed to our advantage just like wine sommeliers. Parts of the book do get repetitive and I wish it was edited a bit better, but still a worthy read.
July 14, 2025
Wikipedia describes smell as “The sense of smell, or olfaction, is the special sense through which smells (or odors) are perceived. The sense of smell has many functions, including detecting desirable foods, hazards, and pheromones, and plays a role in taste.”
I imagine that most of us do not think about our sense of smell until we smell something lovely (a favorite dish being cooked) or something we would rather not smell (as in the odor of the litter box before it is cleaned out). In fact, I remember lack of a sense of smell that the book discusses as a tell-tale sign of a possible COVID-19 infection before we had a test available for detection.
As those who contracted COVID-19 or had a head cold that blocked our ability to detect smells, losing one’s sense of smell, in a word, sucks. And given how important our sense of smell is when we suddenly lose it, there is a woeful lack of research into olfaction as compared to other anatomical processes.
In the book, “The Forgotten Sense: The New Science of Smell—and the Extraordinary Power of the Nose,” Dr. Jonas Olofsson does a splendid job of exploring the world of our sense of smell, as well as detailing his own research in the subject matter. He describes the history of the sense of smell and the current research into the subject.
While I knew that the sense of smell was entwined with the sense of taste (think about the times you’ve had a head cold and was unable to taste your food until you were able to clear at least one nostril), I wasn’t aware of how intricate the dance between the senses was. I took great enjoyment in learning more about the subject of taste and smell.
This was an enjoyable book to read, in fact, I ended up reading late into the night because I liked it so much. I recommend this book to anyone interested in medical history, as well as those of us interested in learning more about the sense of smell.
4/5 stars
[Thank you to NetGalley and the author for the advanced ebook copy in exchange for my honest and objective opinion, which I have given here.]
I imagine that most of us do not think about our sense of smell until we smell something lovely (a favorite dish being cooked) or something we would rather not smell (as in the odor of the litter box before it is cleaned out). In fact, I remember lack of a sense of smell that the book discusses as a tell-tale sign of a possible COVID-19 infection before we had a test available for detection.
As those who contracted COVID-19 or had a head cold that blocked our ability to detect smells, losing one’s sense of smell, in a word, sucks. And given how important our sense of smell is when we suddenly lose it, there is a woeful lack of research into olfaction as compared to other anatomical processes.
In the book, “The Forgotten Sense: The New Science of Smell—and the Extraordinary Power of the Nose,” Dr. Jonas Olofsson does a splendid job of exploring the world of our sense of smell, as well as detailing his own research in the subject matter. He describes the history of the sense of smell and the current research into the subject.
While I knew that the sense of smell was entwined with the sense of taste (think about the times you’ve had a head cold and was unable to taste your food until you were able to clear at least one nostril), I wasn’t aware of how intricate the dance between the senses was. I took great enjoyment in learning more about the subject of taste and smell.
This was an enjoyable book to read, in fact, I ended up reading late into the night because I liked it so much. I recommend this book to anyone interested in medical history, as well as those of us interested in learning more about the sense of smell.
4/5 stars
[Thank you to NetGalley and the author for the advanced ebook copy in exchange for my honest and objective opinion, which I have given here.]
May 12, 2025
I found this book very interesting. Our sense of smell IS really the forgotten sense when compared to sight and sound. I didn’t realize how much a sense of smell (or lack of it) affects the quality of our lives. I learned so many things reading this book, including but not limited to the following:
While we tend to think that animals such as monkeys, rats, and dogs have a better sense of smell than we do, actually humans are more sensitive than many other animals to the vast majority of odor molecules. Human vs rat: 31 to10. Human vs spider monkey: 58 to 23. Human vs vampire bat: 14 to 1. Only the dog beats us. According to the author, “Dogs are more sensitive to 10 out of 15 odor molecules. Dogs are the olfactory kings of the animal kingdom.”
We all know that some people are extremely sensitive to smell while others are not. However, I did not know that our sense of smell decreases with age. This is why old people often do not realize that they have “old people smell” that is often offensive to others.
Our interpretation of smell is very closely linked to the interpretation of olfactory signals by our brain. We might not realize it, but we factor in a lot of information that is not directly connected to the odor receptors in our nasal passages and our taste buds when we evaluate smells. Our memories, visual cues, and subconscious influences all help to determine how we interpret various smells and decide whether they are pleasant or unpleasant.
A gene variant that leads to an increased risk of Alzheimer’s disease is called APOE -e4. Older people who carry this gene (about 25% of the population) have a reduced ability to identify smells. But this gene only seems to affect their sense of smell once they have passed retirement age.
There are so many more fascinating things in this book. It’s only 192 pages but it is full of surprising information. If you are interested in Biology and human physiology, you will enjoy this one.
While we tend to think that animals such as monkeys, rats, and dogs have a better sense of smell than we do, actually humans are more sensitive than many other animals to the vast majority of odor molecules. Human vs rat: 31 to10. Human vs spider monkey: 58 to 23. Human vs vampire bat: 14 to 1. Only the dog beats us. According to the author, “Dogs are more sensitive to 10 out of 15 odor molecules. Dogs are the olfactory kings of the animal kingdom.”
We all know that some people are extremely sensitive to smell while others are not. However, I did not know that our sense of smell decreases with age. This is why old people often do not realize that they have “old people smell” that is often offensive to others.
Our interpretation of smell is very closely linked to the interpretation of olfactory signals by our brain. We might not realize it, but we factor in a lot of information that is not directly connected to the odor receptors in our nasal passages and our taste buds when we evaluate smells. Our memories, visual cues, and subconscious influences all help to determine how we interpret various smells and decide whether they are pleasant or unpleasant.
A gene variant that leads to an increased risk of Alzheimer’s disease is called APOE -e4. Older people who carry this gene (about 25% of the population) have a reduced ability to identify smells. But this gene only seems to affect their sense of smell once they have passed retirement age.
There are so many more fascinating things in this book. It’s only 192 pages but it is full of surprising information. If you are interested in Biology and human physiology, you will enjoy this one.
March 30, 2025
This had a lot of fascinating information in it and I highly recommend it. It touches on how problems with the sense of smell can be early indicators of disease, how smell training can improve cognitive functioning, the physiological processes of tastes, how COVID uses smell receptors to attack your brain, and even how research has shown a link between your level of disgust by smells and your political leanings.
May 25, 2025
I've been handing out a lot of five star reviews but the nonfiction I've been picking up is all just so good. As someone who agrees that smell is our most important sense maybe I'm biased with this one. but it taught me so much about COVID parosmia, how we connect with each other via food, and how we should all be nosewise. I also found it hilarious to mention that when baby Jesus was born no one brought him toys, they brought him "things to smell". This was a fun, quick read.
June 4, 2025
Pleasant, if not a little meandering. The history and language associated with smell was particularly intriguing, especially how the idioms associated with each sense, (smell is related to intuition, vision to insight, taste for discretion), and how the sense of small came to be devalued. The broad content is front-loaded; the latter half deals with loss of smell due to COVID-19 and different treatments for smell recovery and concludes with a long-winded diatribe about sommeliers.
June 27, 2025
maybe a 3.5/5. I thought the sections on smell training/nose training were FASCINATING. Some of the other sections rehashed territory I've seen elsewhere (he frequently references Constance Classen and I have read her book). Weird tangent about weight in one section that was ill-conceived.
September 15, 2025
Started off pretty well, but soon devolved into the dreaded and rather dry enumeration type of book; a well meaning and well respected scientist dishing out facts and studies on human olfaction; in itself pretty interesting stuff, but this story can be told in a far more gripping and exhilarating way that would have you sit and the edge of your seat.
May 23, 2025
This was an interesting book. For many years (decades), I did not have much of a sense of smell - I could only detect a few smells like skunk. I had an experimental procedure done and among many other results, I now have a sense of smell. It is not strong, and because I had no experience with many of the smells, I can't identify a lot of them (I ask my husband what I am smelling and he tells me and I try to remember), but I can smell them. I also don't seem to have any judgement on whether they are good or bad, they are just odors. The skunk smell doesn't even really bother me.
I have to say that there are good things and bad things about being able to detect smells. It was a good thing when I worked at a veterinary college as others were upset when things like blowing out the autoclaves happened. All I had was a metallic taste in my mouth and they were all disgusted. However, I could not detect a burning smell and that can be concerning. Thanks goodness my experiences were only during cooking.
This was an area of interest for me and I found the book very informative.
I have to say that there are good things and bad things about being able to detect smells. It was a good thing when I worked at a veterinary college as others were upset when things like blowing out the autoclaves happened. All I had was a metallic taste in my mouth and they were all disgusted. However, I could not detect a burning smell and that can be concerning. Thanks goodness my experiences were only during cooking.
This was an area of interest for me and I found the book very informative.
June 2, 2025
Very interesting book about the sense of smell, which really is, in a sense, the forgotten sense. Much more emphasis is placed on sight and hearing than smell. But it is amazing how important the sense of smell really is, and how much it can affect us in many ways. For example, the sense of taste is heavily reliant upon and connected with the sense of smell. While it is often thought that humans have a much lower sense of smell than many other animals, the truth is that humans, for the most part, have a very good sense of smell, and actually better than most animals. Only the dog beats us out in the smell arena. A lot more emphasis has been placed on the sense of smell in recent years, due in large part to the Covid19 virus, which impacted the sense of smell in many people. There are many reasons for our sense of smell degrading, such as illness (Covid19 or other diseases), and simply growing older. If you have any interest in human physiology, you will enjoy this short read.
June 20, 2025
In the era of COVID, this book has immediate cultural relevance in its focus on smell as a truly indispensible mode of engaging with the world.
The author covers the topics of anosmia (lack of smell) and parosmia (a disrupted sense of smell) with the kind of compassionate scholarship endemic to those researchers whose work becomes unexpectedly and painfully relevant in the world outside of the laboratory.
I will concede that there seems to be something of an uncertainty on the author's part as to whether olfactory preferences are rooted primarily in genetic predisposition or mostly in learned associations. The answer is probably a resounding "both" in the majority of cases, but I would have appreciated more speculation on that particular subject.
In any case, this is an eye-opening (nostril-opening?) introduction to the role of the nose and its relationship to other chemosensory phenomena.
The author covers the topics of anosmia (lack of smell) and parosmia (a disrupted sense of smell) with the kind of compassionate scholarship endemic to those researchers whose work becomes unexpectedly and painfully relevant in the world outside of the laboratory.
I will concede that there seems to be something of an uncertainty on the author's part as to whether olfactory preferences are rooted primarily in genetic predisposition or mostly in learned associations. The answer is probably a resounding "both" in the majority of cases, but I would have appreciated more speculation on that particular subject.
In any case, this is an eye-opening (nostril-opening?) introduction to the role of the nose and its relationship to other chemosensory phenomena.
December 22, 2024
Despite having a favorite scent (orange blossoms), I’d never given any thought to how important that sense is. This brief, informative volume, discusses just that. Some people I know lost their sense of smell with COVID and I always thought how that must have been the least of their symptoms. Reading about the implications was eye-opening. Jonas Olofsson has performed fascinating experiments to explore the biology of smell, as well as the psychology of it. The book includes some animal facts, cultural aspects and even tips to improve your smelling. Written in an approachable language, it is clear and easy to understand. Highly recommended to anyone who enjoys learning about the human body.
I chose to read this book and all opinions in this review are my own and completely unbiased. Thank you, NetGalley/Mariner Books.
I chose to read this book and all opinions in this review are my own and completely unbiased. Thank you, NetGalley/Mariner Books.
February 28, 2025
I am conflicted about this book. There are many good insights within its pages. As someone with a strong sense of smell, I was fascinated by many of the facts and studies presented (how color impacts your smell, how body odor can either be good or bad depending on your relationship with a person, how you smell through your throat!). The author truly knows his stuff, and being a researcher himself allows us to get a nuanced picture of the subject matter. So, why do I rate it so low? The author repeats himself A LOT. It felt like I read the line "COVID impacted people's ability to smell" twenty times before we even got to the section on COVID (which again, had good insights!). It made the reading experience more loop-like and longer than needed. Maybe that's just me; give it a try yourself.
April 28, 2025
If you like learning something new this book is for you! Olofsson touches on so much regarding our olfactory sense, including the history of the science (so much more interesting than I would have thought!), how our sense of smell works, its connection to our memories and other senses, and the loss of smell (specifically regarding Covid 19).
I feel alot of science books will use language that makes the knowledge inaccessible to people outside of those fields. In The Forgotten Sense however; Olofsson does a great job of explaining concepts in a way that can be easily followed and remains engaging. Even the more technical parts where he discusses the neural interactions are presented in a way that are digestible to the reader.
Overall I loved this book, I learned a lot and I am going to be forever conscious now about the processes happening when I am eating and sniffing!
I feel alot of science books will use language that makes the knowledge inaccessible to people outside of those fields. In The Forgotten Sense however; Olofsson does a great job of explaining concepts in a way that can be easily followed and remains engaging. Even the more technical parts where he discusses the neural interactions are presented in a way that are digestible to the reader.
Overall I loved this book, I learned a lot and I am going to be forever conscious now about the processes happening when I am eating and sniffing!
May 4, 2025
kind of a slog for me to read personally… its easy to understand the concepts presented but the text is fairly plain and matter-of-fact (as compared w luca turin’s secret of scent which i enjoyed much more! the scientific focus is slightly different in that one) … i was hoping for more re: chemical processes, but The Forgotten Sense primarily explains the brain’s essential relationship in processing information from our nose.
TLDR the brain combines our memories, expectations, and other sensory input to interpret olfactory information! for ex: we can perceive the same smell (odorant molecules) as delicious or repulsive, depending on the context in which they’re presented. it is also possible to train the brain to strengthen our sense of smell !
TLDR the brain combines our memories, expectations, and other sensory input to interpret olfactory information! for ex: we can perceive the same smell (odorant molecules) as delicious or repulsive, depending on the context in which they’re presented. it is also possible to train the brain to strengthen our sense of smell !
November 26, 2025
This is my first step into non-fiction reading. And I am finding it very interesting. there were many eye-opening facts regarding humans ability to smell compared with other animals on our planet. I also found that information regarding support for individuals who may have problems smelling and tasting A useful addition to the entire body of literature. some of the websites that were discussed were rather obscure and most likely would have been very difficult to find through simple searches. anyone who has had issues with a loss of smell or a loss of taste, especially since the covid-19 pandemic might find this to be a very interesting read.
December 28, 2025
Would rather give it 2.5 but …. This book had interesting tidbits about the sense of smell. It was used to diagnose illness by doctors ages ago. Now I know why doctors wore those beak like things way back when. Basically smell was once a more dominant sense than it is today. Its position among the senses has changed over time along with how smell is used and for what. My book club thought the book had its moments but basically seemed to drag. One of us was surprised it was less than 200 pages. In short, while well written it might have been better received if it was read as a series of magazine articles. Small bites of smell knowledge would be much better.
February 3, 2025
Fermented herring is a polarizing topic. Many people find its smell disgusting. But Jonas Olofsson thinks it’s scrumptious. In his new book, The Forgotten Sense, Olofsson, a leading smell researcher and professor of psychology at Stockholm University, where he directs the Sensory Cognitive Interaction Lab, explains that smell preferences and capabilities are like fingerprints; each person’s is unique. This nugget is part of a crash course on what we need to know about our nose. We learn just how vital the sense of smell is to our lives and that many of us grossly underestimate its power.
The book covers the mechanics of smell, as well as medical and social history of all things olfactory. Olofsson also highlights new smell science research and technology, including AI-directed sensory smell games that can enhance our smell abilities, studies about the connection of human phenomes and smell, and scientific findings about the loss of smell from COVID-19.
The Forgotten Sense makes a complex topic accessible for everyone. Olofsson's clear, crisp writing is infused with wit and peppered amusing anecdotes. Highly recommend!
The book covers the mechanics of smell, as well as medical and social history of all things olfactory. Olofsson also highlights new smell science research and technology, including AI-directed sensory smell games that can enhance our smell abilities, studies about the connection of human phenomes and smell, and scientific findings about the loss of smell from COVID-19.
The Forgotten Sense makes a complex topic accessible for everyone. Olofsson's clear, crisp writing is infused with wit and peppered amusing anecdotes. Highly recommend!
April 22, 2025
This book revealed some interesting insights into the world and psychology of smell. I enjoyed the facts and tidbits and would like to further test my own sense of smell. I was surprised by how studies have shown that people's reaction to certain smells is associated with political views.
The author termed people disgusted by certain smells "thin skinned people." As a science-based book an objective or impartial term seems more appropriate.
The author termed people disgusted by certain smells "thin skinned people." As a science-based book an objective or impartial term seems more appropriate.
January 25, 2025
This was such an interesting book about the sense of smell, and how it affects and pervades everything in our lives. Very relatable, if you've ever lost your sense of smell and know firsthand what a disconcerting feeling that is.... as if the whole world has gone dark and can no longer be understood.
April 2, 2025
This is an overview of the importance of the sense of smell and its tendency to be overlooked by science. The topic seems to have spawned many recent advancements due to the post Covid complications suffered by many who have a permanently lost or distorted sense of smell. It's an interesting read that touches lightly on everything from sommeliers to new methods for regenerating the lost sense.
April 5, 2025
This was a very interesting book about some of what research has shown about the sense of smell. It was more from a psychological bent then biological , as the author studies psychology. One subject that was interesting was the study of people who lost their sense of smell due to covid and attempts to help them recover it.
November 4, 2025
I have a new appreciation for the sense of smell. The author (full disclosure: my friend’s son-in-law) has managed to explain complex research in layman’s terms. I particularly liked the sections on smell as it relates to culture, dementia and even Proust. I will be following his advice on smell training!
June 8, 2025
Interesting slim volume on “the new science of smell” with chapters on smelling games, loss of smell as alert for diseases like Parkinson’s or dementia, loss of smell during COVID, skills of wine sommeliers & bouquets, and other tantalizing facts about the olfactory system.
February 13, 2025
Really interesting and made me appreciate my sense of smell!
February 26, 2025
Interesting subject, not the best writing, so stars are more for actually researching and writing about it.
April 25, 2025
What an interesting study of the sense of smell - written in words that are understandable. Smell affects us all in so many ways that we don't realize. I loved this book.
June 20, 2025
Hence, return it to the library when it was due. i hope to give it another try later.
Displaying 1 - 30 of 36 reviews