Dogs obviously have incredibly more advanced olfactory systems but I feel like you're downplaying humans here. I'm pretty sure there's hundreds of very specific smells I could identify pretty well. Smell of home, pencil rubbers, chalk clouds, rotten bananas, denim.. things do have quite specific smells and there's a lot of things.
I think it’s pretty established that humans are very good with smell. We just aren’t very sensitive compared to dogs
Those are classes of things, not specific objects. We all know the smell of erasers, but can we identify the smell of a specific eraser? Part of it is sensitivity but it is also largely that our brains are not designed to associate smells with individual objects. Think of how we handle faces, which we can spot even if at a different orientation than we have seen before. Or how we can hear a specific voice amongst a crowd. Dogs do that with scent profiles.
"2008, Betsy, a Border Collie, knew over 345 words by the retrieval test, and she was also able to connect an object with a photographic image of the object, despite having seen neither before."
(mentioned in article) "Rico initially knew the labels of over 200 items [and] inferred the names of novel items by exclusion"
"2013, a Border Collie, "Chaser", who had learned the names and could associate by verbal command over 1,000 words[...], and [was] capable of linking nouns to verbs"
[1] https://en.wikipedia.org/wiki/Dog_intelligence#Learning_and_...
"According to McGann, our olfactory inferiority is nothing but a 150-year-old myth born of erroneous assumptions and faulty science."
The answer from the article is, essentially, because dogs are much better at odor detection than us. It weirdly seems to say because we have the ability to sense odors we are better than we think we are, which implies we think we can’t smell at all or something. But dogs are much much better than us.
“”” Besides having more olfactory receptor cells than humans, dogs also boast a specialized snout adapted to methods of breathing that deliver a steadier stream of information-rich scent. Dogs and some other animals even experience scent differently. Their olfactory system allows them to smell liquid phase chemicals that aren't airborne—think of layers of urine and other liquids on your neighborhood fire hydrant—by working like a pump to deliver them to a specialized nasal organ. “””
Which is pretty indicative that as everyone knows from daily experience with dogs, dogs are better at smelling things than humans. There may be a range over which that superiority falters at some chemicals but I saw nothing other than headlines and pop science supposition that indicates humans are superior at smelling than dogs.
```For example, Laska notes, the total number of odorants for which dogs have an established, lowest detectable threshold level is 15. Humans actually have a lower threshold for five of those. “Those five odorants are components of fruit or flower odors,” he says. “For a carnivore like a dog those odorants are behaviorally not as relevant, so there was no evolutionary pressure to make a dog's nose extremely sensitive to fruit and flower odors.”```
Look at our memory for faces. It isn't all about eyesight. Our brains have specific circuitry for faces. Dogs have the same for smell. Sensitivity is one thing, how the brain is wired is another.
I rememeber:
* how English Cadbury's smells
* how El Rey Cordoba milk chocolate (from Venezuela) smells
* how Hershey's smells
* how hot chocolate made with Swiss Miss mix smells
* how Toblerone smells
We're wired to be able to pull up those memories and imagine a smell, but not to be able to identify what we're smelling when it's right in front of us.
I think you are speculating cause.
Culturally we tend not to communicate much about smells - it could just as easily be that most of us have the ability but it is never trained because it isn't much use to us.
Anecdotally I know people with a wide range of different olfactory abilities.
It is interesting to try and think of how we could test for the ability. Perhaps not testing for my pencil, but something else - a child - a dog - shoes - urine.