The Scent Of Your Thoughts

[Deepwater6]

There is a great article in the Oct. 11 issue of Scientific American titled "The scent of your thoughts". The article makes the case that humans are usually unaware that they communicate through chemical signals. Of course many of us have heard that women's menstrual cycles tend to syncronize when they spend time together, but the article goes beyond that. It proposes humans can smell the fear in other people's sweat they tested watching horror movies and happiness when watching a comedy.

 

It would have given us an edge in early evolution. The compounds must be active in very tiny amounts, potent below a conscious scent threshold. the article goes on to say that not only can we syncronize our reproductive cycles, we can also identify kin, detect fear or stress in others and get a sense of "not tonight honey"

 

I guess my questions to this site are the following, do you agree with these results? Has anyone been concious of the scent on another?

 

I have tried to focus on this since reading the article, but I can't detect my wife's moods by scent as far as I can tell. Maybe I'm just used to focusing on voice tone and body language. I did hear of a woman who made her husband go to the doctor because she could smell sickness on his breath and she was correct.

 

I'd like to hear the opinions of this site thanks.

 

Deepwater

[Deepwater6]

I also just realized that I posted this in the mathmatics section where it doesn't belong, sorry about that.

[belovelife]

have you ever had a memory tht made you remember a smell, and smeeled the smell again, like a tree in youth

 

or the taste in your mouth like the taste of a kiss, when you see a girl, and go for a kiss and she kisses you back

[Deepwater6]

Yes I have, as I get older these smells/tastes get more and more common for me. I guess because there is more to choose from in comparison. I'd love to know how much of our sense of smell we use, how much audio, etc. Just 10% of the brain correct? If we could figure out how to get these senses expanded the world would be filled with nostalgic feelings and memories.

[belovelife]

nostaligic feelings and language :)

 

[Rade]

Makes sense if you consider that when you watch a horror movie, your body releases hormones associated with fear or danger response, and these hormones are then released in sweat. Now, another person with a genetic affinity to sense via smell the fear hormones in your sweat, as compared to similar smell of the same fear hormones in their own sweat when they experience danger, should be able to tell apart different sweat samples from other people. I have no idea how many humans in the population have this type of genetic affinity to detect hormones of fear in sweat. Neat research.

[Deepwater6]

That's a good point Rade, I wonder why our evolution as a species hasn't amplified this for us? In the same way a blind person's hearing improves to make up for the lost sight. Under normal circumstances we haven's lost anything, but if evolution started the process why would it only give us the minor ability to do it? This improved ability would help us in countless ways. Unless it was alot stronger in the past and now it's starting to fade away like all over body hair.

[Rade]

I wonder why our evolution as a species hasn't amplified this for us?

Basically because it is not adaptive to have affinity to smell fear within the sweat of other humans, we can see the fear in their eyes and body language and act on it. This leads to the prediction that the ability to smell fear hormones in sweat is not very common and has neutral adaptive value. Here is a hypothesis to consider, perhaps the gene is maintained in the human population as a whole by random matings of the sighted with the blind. That is, the gene has some adaptive value for the blind to know when to move away from the odor of fear in the air. Would be interesting to see if this ability to smell fear in sweat is more common within the blind than the sighted, if so, then here may be how it was amplified by natural selection.

[Deepwater6]

I don't know of any official study about adaptive genes that has ever been done, but I'll do some research into it to see what similar research was done.

 

Rade, since you seem to have some background or at least a better understanding of this topic than I please explain something to me. It is said that a Polar Bear has evolved with a sense of smell of at least a mile. Now no matter how hard I want my children, or my childrens children to have increased sense of smell I can't make the next generation have that better sense. No matter how much I may think they will need it for survival, So how does nature know to keep increasing the Bears sense? What does the mother do differently to make this sense head in that direction? How does nature know that for it to survive the bear must slowly get this greater sense? With the melting of their habitat will this sense be improved for them so they can find prey at farther distances?

 

If humans stood up and walked on two feet because they could use less energy, see over tall grass for prey and preditor, etc.. then why didn't apes evolve along the same direction. Why do they continue on all fours?

[JMJones0424]

Deepwater- there is no entity called Nature that directs species to become better adapted to their environment. Instead, heritable traits that increase an individual's ability to survive and reproduce are more likely to be passed on to the next generation, conferring an increased chance of survival on to their offspring. So, nature did not decide to make polar bears able to smell prey from a longer distance. Bears with a better sense of smell are less likely to starve due to not finding food, and those with a poor sense of smell are more likely to starve. The genes that allowed for better smell are more likely to be passed on to the next generation, while the genes that allowed for worse smell are more likely to not be passed on. This is called natural selection, and this is one of the primary factors driving evolution. Evolution is not the change of individuals over time, but of populations over generations.

 

Humans are apes, so it would be more correct to say that some branches of the ape family tree, notably genus Homo, evolved the ability to walk on their hind legs due to a competitive advantage it gave them in their environment. Not all species of apes have evolved this ability because either 1) Walking on hind legs does not confer a competitive advantage in their environment or 2) The genetic traits that allow them to walk on their hind legs come with other changes that make it overall a net negative adaption and is selected against.

[Turtle]

it is certainly true that humans have a different sense of smell than other animals, but i recall hearing that Amazonian (i think) Indians can identify more than 20 (i think) animals by the smell of only their urine. it is not that they have evolved a better sense of smell than other humans, only that they have a use for training & using what sense they do have. on my own part, when my children were young and still at home i recall that i could tell them -and their clothing- apart by scent alone.

 

after some searching i could not find the exact reference, but i found what i think it came from. this is a text summary, but i did see the pbs program it comes from so that may be where i heard about the urine business in the first place.

 

Guns, Germs, and Steel

 

Inequalities in the modern world stem from the same difference in development that occured between 11,000 BC and 1500 AD. There is no evidence of differences in ability that can be demostrated when differences in education and experience are taken into account.

...

Note that nowhere in this discussion is there anything about the advantages of the people themselves. And there is none. A look at Eastern US and New Guinea will quickly show this is so. Hunter-gatherers know well all the locally available wild species. Ethno-biologists' studies have shown people to be extremely skilled in knowing names and uses for as many as 1,000 or more plant and animal species. The author's own experience in New Guinea reflects this and, in addition, whenever he took a native New Guinean with him to other parts of the island, they would talk with local people about plants and animals and gathered potentially usefull plants to take home. Farmers loose this type of knowledge when it is no longer needed. ...

 

link to PBS program series: >> Guns, Germs and Steel @ pbs

[BradyWang]

it is certainly true that humans have a different sense of smell than other animals, but i recall hearing that Amazonian (i think) Indians can identify more than 20 (i think) animals by the smell of only their urine. it is not that they have evolved a better sense of smell than other humans, only that they have a use for training & using what sense they do have.

 

I'm not surprised by this as I have both dogs and cats in my house and their urine smells very different.

[Turtle]

I'm not surprised by this as I have both dogs and cats in my house and their urine smells very different.

 

that's interesting. i wonder if any pet owners that have multiple dogs or multiple cats can smell differences between or among individual animals of the same species. ?? don't give me that look barney! :dog: i know it wasn't fluffy. :lol:

[Deepwater6]

that's interesting. i wonder if any pet owners that have multiple dogs or multiple cats can smell differences between or among individual animals of the same species. ?? don't give me that look barney! :dog: i know it wasn't fluffy. :lol:

 

I have 3 dogs, A 9yr old Lab/Chow mix and (2) 1yr old brother and sister Golden Ret./Lab combo pups. Better known around here as the Bumpus hounds. They are house trained now, but I don't remember being able to discern which one had an accident by the smell of the urine I was cleaning up. I can however smell a difference in each of my dogs personal smell. In the same way someone mentioned earlier about being able to differentiate the kids clothing by the smell.