Thus, the investigators adopted an experimentally rigorous psychosocial paradigm in which sixteen undergraduate female participants were placed in a custom-built, computer-controlled “olfactometer” inside of which male faces appeared sequentially before them on a screen. One of five odors (two “unpleasant”: synthetic body odor, rubber; two “pleasant”: geranium, male cologne; and one “neutral”: clean air) was randomly pumped into the experimental chamber and paired with the face. There were forty faces in total, and each face was randomly presented three times so that every participant experienced it paired with at least one odor from each of the three categories (unpleasant, pleasant and neutral).
As you might expect, the young women in this study consistently rated the male faces as being significantly less attractive when presented with the unpleasant odors. In addition to these findings justifiably putting a smile on the faces of perfume company executives everywhere, there are other fascinating implications for such data, too. According to Demattè and her coauthors:
In the years to come, our findings might also be relevant in the technology sector, given recent developments in the area of multisensory applications, such as the possible use of olfactory cues in messaging applications, electronic picture storage/retrieval and enhancing the sense of presence in virtual reality.
I must say, I’m not entirely sure how that would look in practice (perhaps a spritz of sassafras from a designated pinhole in your iPhone to match your husband’s ring tone, or a scroll-down menu of scent accoutrements for Match.com profiles), but I do like the general idea.
As far as natural body odors go, scientists have found repeatedly that the less a person smells like you, the more attractive—or rather, the less repulsive—you find their armpit aromas. To evolutionary psychologist Glenn Weisfeld from Wayne State University, the reason we prefer dissimilarly scented others is obvious: since olfaction plays a key role in identifying who is genetically related to us and who isn’t (in some studies, participants with especially strong odor detection abilities can even successfully discriminate between the body odors of identical twins raised apart and those of fraternal twins raised together), being specially repelled by the malodorous fumes of our biological kin functions to promote incest avoidance.
To explore his basic evolutionary hypothesis, Weisfeld and his colleagues asked family members to smell each others’ body odors—not the most pleasant scenario, you’ll probably agree (for me an outright nightmare), but a necessary one for scientific purposes. A total of twenty-one families from the Ontario area participated in this study published in a 2003 issue of the Journal of Experimental Child Psychology. Each person in the family was given a new, all-white, identical t-shirt and was instructed to wear this shirt to bed for three consecutive nights. No scented soaps or perfumes were used during this odor absorption period, and shirts were kept in their own sealed plastic envelopes during the day.
After three nights, each family member was tested in isolation and asked to compare the shirt worn by another family member with that of an unrelated control subject (matched by gender and approximate age). The participants were asked first which odor they preferred, and then which shirt was that of their mother, father, child or sibling. A few interesting findings emerged from this study, some of which lends support to Weisfeld’s incest aversion hypothesis. First, both mothers and fathers could distinguish the smell of their own child but, somewhat curiously, mothers “strongly preferred” the odor of the control child. Fathers demonstrated a similar trend in odor preference, but for them the effect failed to reach statistical significance. Older children in the study (those aged 9-15 years) likewise preferred the body odor of the control adult man and woman to that of their parents. Furthermore, these older children strongly preferred the scent of control children in opposite-sex trials, but showed no preference for the body odors of their same-sex siblings versus controls. That is to say, brothers found their brothers’ body odors as mutually offensive as another boy’s body odor, and the sister pairs showed the same pattern of indifference response.
A final recent study worth mentioning was one conducted by Charles University of Prague anthropologists Jan Havlicek and Pavlina Lenochova, who actually answered the age-old question of whether carnivorous people smell worse to us than vegetarians. In other words, “the aim of this study was to test the effect of red meat consumption on axillary odor hedonicity.” In a 2006 article published in the journal Chemical Senses, Havlicek and Lenochova convinced seventeen disease-free, nonsmoking male students ranging in age from nineteen to thirty-one years to eat strictly defined diets. (They were paid about $35 for their participation in the study, a real bargain.) Half of the participants were assigned to the “meat” condition for two weeks, and the remaining half to the “non-meat” condition for this period.
During the first ten days, these males could choose from a list of prepared meals and had to select at least one main dish out of the list every day. “The individual dishes were elaborated,” write the authors, “to differ in meat content only (e.g., vegetable risotto/pork risotto).” The final three days of the special diet were even stricter; during this time, the participants were hand-served lunch and dinner to precisely control for their dietary intake—the meat group, for example, was observed wolfing down a 100-gram red meat dish for each main course. To rule out other possible factors, Havlicek and Lenochova forbade the participants from sleeping in the same bed as their partner, engaging in rigorous exercise, using perfume, deodorants, antiperspirants, aftershave and shower gels, eating garlic, onions, chili, pepper, vinegar, blue cheese, cabbage, radish, fermented milk products and marinated fish, consuming alcohol or other drugs—and even from having sex (those who confessed to such venal sins were excluded from the final data analyses). After two weeks on either the “meat” or “non-meat” diet, participants then switched to the other diet for the following two weeks, so that each man’s body odor was assessed on both diets.
At each two-week interval, thirty female students from the same university were asked to inhale the scent of cotton pads that had been affixed to the men’s underarms the entire day before. I don’t know whether it would have been worse being one of the male “odor donors” in this study and having to change my diet so drastically for such an extended length of time, or being a female odor judge and having my delicate olfactory sense pierced by even a moment of such miasmic horrors. (By the way, the women received a perfume tester and a chocolate bar for their help.) The ends justified the means, though, at least for the sake of vegetarian males in Prague. We now know that, even independent of where women are on their menstrual cycles, the “odor signatures” of men on a non-meat diet are perceived by fertile women to be less intense, more pleasant and more attractive than their meat-eating peers.
Now, if you’ll excuse me, I have the sudden urge to take a shower.
In this column presented by Scientific American Mind magazine, research psychologist Jesse Bering of Queen's University Belfast ponders some of the more obscure aspects of everyday human behavior. Ever wonder why yawning is contagious, why we point with our index fingers instead of our thumbs or whether being breastfed as an infant influences your sexual preferences as an adult? Get a closer look at the latest data as “Bering in Mind” tackles these and other quirky questions about human nature. Sign up for the RSS feed or friend Dr. Bering on Facebook and never miss an installment again.
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26 Comments
Add CommentIt would be nice to, just once, be able to read an article on this site without these "rollover" ads popping out whenever they feel like it and refusing to go away. At least couldn't you put them somewhere where they do not cover up the text of the articles?
Reply | Report Abuse | Link to thisAplastic, To solve your trouble I suggest using Firefox with this add-on called NoScript https://addons.mozilla.org/en-US/firefox/addon/722
Reply | Report Abuse | Link to thisI am very much surprised to see that females prefer the odour of men on a vegetarian diet before those on a diet of meat considering how vegetarianism in no way can be considered a normal, or even sufficient, diet for a human being. Evolutionary speaking a man who does not suffer the risk of malnourishment should be considered more attractive -- even in the odour department -- than a man who does face such a fate (at least in the evolutionary environment where human sense indeed were fine-tuned).
Reply | Report Abuse | Link to thisI suppose it only shows how much there is yet to discover about the human being and the processes that give rise to their behaviour. In the meantime, awaiting such discoveries, I shall turn to the original paper to see if any of the information therein can explain the puzzling fact mentioned above.
This is no add for a product, I have used I.E. from bill sence 1990 , the FireFox product works well.
Reply | Report Abuse | Link to thisThose readers who would like to explore (from a less sexist angle of presentation), the human body odor angle, please see the one-page semipopular article at P: 16 of the magazine Consecration (Nov-Dec 2008):
Reply | Report Abuse | Link to thishttp://www.lordsrikrishna.net/Cons%20nov-dec%2008.pdf
thanks
I wonder how a question on same sex attraction would implicate olfactory perceptions. Could it be possible to suggest lack of smell discrimination in homosexuality. Since nature makes attaction with opposite smell a process of natural selection.
Reply | Report Abuse | Link to thisIncidentally, the title of the article in Consecration is :
Reply | Report Abuse | Link to this"Sniff, Sniff, We Are Earthlings."
I just prefer to say females have noses of hound dogs then to write this long long article, scientifically of course ;{)>
Reply | Report Abuse | Link to thisAs i was reading this interesting article a question rose to my mind that long since has been unanswered (at least for me) .
Reply | Report Abuse | Link to thisIt�s about the phenomenon called FEMALE EJACULATION and the human perception of odors ( particularly the unconscious perception of pheromones) .
Here is what i think: it is long proven that many women do have different amounts of fluid excreted from their urethras and possibly vaginas while having orgasms ( popularly known as female ejaculation). It is known that this liquid is far from similar to urine and has a significant amount of prostatic antigen. So... i think this liquid is charged with pheromones which are then impregnated into the male partner. Then, this particular odor is designed to repulse possible female partners that the male may have afterwards.
So, the female�s nature tries to secure this worthy male (which is "viril" enough to make her orgasm)to herself, and via pheromones prevent further female rivals steal her male.
I think it�s worth an experiment to prove it, kind of the shirt�s sweat, and see if women are significantly more repelled by this new odors.
=)
Greetings from Mexico !
Perhaps we can identify a new form of intelligence-Olfactory Intelligence, i.e., what the nose knows....
Reply | Report Abuse | Link to thisWith a nose like mine, my O.I. must be way beyond 130
Reply | Report Abuse | Link to thisYou are incorrect about vegetarian diets being insufficient or making a person particularly subject to malnutrition. The American Dietetic Association and Dietitians of Canada agree that vegetarian eating plans are healthful, nutritionally adequate and provide health benefits in the prevention and treatment of certain diseases. Some studies suggest that vegetarians may live longer than their omnivorous counterparts and others find little difference in mortality.
Reply | Report Abuse | Link to thisPerhaps it's the enormous amount of meat that Western societies consume that affect body odor. If meat was an occasional food, as it is in most societies today, the difference might be less pronounced.
This was an informative article, but I would suggest tightening it up a little. It's length makes it a little arguous to read, and shortening it by 50%, in my honest opinion, would be of great benefit. I do like your column though. Keep up the journaling of weird and interesting topics.
Reply | Report Abuse | Link to this[Cerebrl]
Opps, that would be arduous ... not arguous. Sorry for my typo.
Reply | Report Abuse | Link to thisI think you're on to something there: the first group of men would be sniffed after having been marked naturally in this manner, the second group would have been sprayed with an inert liquid from a spray bottle during the course of a fake orgasm, and the control group would be men who were not sprayed at all, but had been watching WAY TOO MUCH PORN.
Reply | Report Abuse | Link to thisNice article, but I wanted to read more on how males respond to female ordors.. I came accross this article while I was trying to understand why I started to smell like my boyfriend.. Since we started having sex, my body odor smells like his! Anybody knows why?
Reply | Report Abuse | Link to thisI am wondering if anyone can answer this ! Myth of Fact ?!?! I was married for 19 years, really had a hard time with the marriage, not a normal attraction, more a committment. Last year I met a man whom I was amazingly attracted to on all levels. We both came to realize that we have the same underarm odor. Is that actually possible and does that play a role in our connection?
Reply | Report Abuse | Link to thisIt would be interesting to see a study on same-sex attraction in regard to natural body odor. I am gay and I know that there is a certain percentage of the gay population that is very attracted to a "strong male scent". This article appears to be aimed more at the female to male view, I wonder if there is a difference with the male to female aspect. Does a woman's body odor effect a man one way or the other?
Reply | Report Abuse | Link to thisYou and your mate probably smell similar due to your shared diet, and environment.
Reply | Report Abuse | Link to thisOn the How do males respond to female odor - does the female scent of one female offend a male?
When women socially group in small troops their menstrual cycles sync up; suggesting they are mutually accepting of a Alpha-Male?
with due respect to dr berring, he shd confine his research to other males who are inclined like him. his expert articles olfact of two male pheromones instead of a male and a female.
Reply | Report Abuse | Link to thisscientific opinion all along said that human anatomy, physio, juices,dentition, all pointed out to the vegetarian preference. will the observer defend his such strong assertions?
Reply | Report Abuse | Link to thisObserver did you read godless quote on vegetarian diet?
Reply | Report Abuse | Link to thisI find it odd,that the focus of the article is the armpits.I realize that it is from the female point of view.But coming from a male author, I can only assume that he is homosexal,because being a hetrosexal I can say that the focus for most males is the odor from the female genitela.From a very young age I could smell a women from down wind from quite a distance.Having grown up in a rural area where I wasn't exposed to a large number women,I may have been more sensitive to the smell,but I could tell when a female was in the mood for sex just from the smell.this might sound weird,but I have spoken to many other men who claim to have same abilty.As for others who can't,they claimed to find the smell unpleasant,and were at a disadvantage when it came to finding partners,something I myself never had a problem with.It makes wonder if those with out this ability have a harder time passing on their genes?
Reply | Report Abuse | Link to this"Smell" will continue to have a strong influence on how we perceive and judge our surroundings, including of course deciding who we want to mate with in a perfectly natural setting. Going back millions of generations back in time, it is likely that senses like "hearing" and "vision" evolved much later than the sense of "smell", so this still has a strong bearing (rightly so!) on how we judge our surroundings. Smell ultimately scores over all other opinions we may have formed from mere "looks" initially. It is not a co-incidence that noses have evolved right above the mouth - perhaps intended to smell food and judge its suitability before we consume it. As a wandering mammal in forests, the sense of smell played an extremely beneficial role in staying away from dangers. We must continue to rely on this powerful medium even in today's "artificial" world.
Reply | Report Abuse | Link to thisTheres a wide spectrum within the categories 'vegetarian' and 'meat eater'. The notion of what is 'healthy' heavily depends on how you approach each. Humans evolved with a wide and varied diet. Extended periods of vegetarian diet would have been common. A diet consistently overweighted with meat is not in line with that. So on your theory that kind of diet could be expected to produce an unattractive smell.
Reply | Report Abuse | Link to thisI believe vegetarianism can be healthy if done carefully, but it is much easier and sensible in my view to eat a balanced diet including some meat. The kind of diets many people eat today focused on meat are totally unbalanced.
Actually, vegetarianism/veganism is now being considered superior to the meat diet, based on the digestive and physical characteristics of our bodies. I.e. stomach acid concentration, intestinae tract, saliva etc. Plant protein is shown to be healthier and superior to meat, which must first go under an extensive breaking down process which happens through putrification, (in your 30 ft. long intestine), whereas plant matter is digested in a much simpler way, where the amino acids can be readily absorbed and utilized by the body. Here is a good comparison of a carnivore vs a herbivore diet.
Reply | Report Abuse | Link to thishttp://www.stevepavlina.com/blog/2005/09/are-humans-carnivores-or-herbivores-2/
It is 100% true that a diet free from saturated animal fat, cholestrol, dioxins, and the other horde of toxins in meat, is healthier for you. Obesity is linked to nutrition, and lack of excersise. There are absolutely NO overweight vegans.