Smell You Later, Alligator!

an examination of human pheromones by

Jefferson Scott

Two people see each other across a crowded room. They both like what they see. He makes his way over to her and asks if he can sit down. She agrees. He says something he hopes is witty and engaging. Only now something’s wrong. Her whole demeanor has changed. She makes some excuse and melts into the crowd.

What happened? Did he say something ungentlemanly? Did his breath mint fail him? Or was it her problem—does she just have some "issues" that need to be worked out with a counselor?

There is surprising new research suggesting that something else entirely might be at work, something called pheromones.

Pheromones are chemical compounds (often odorless) found in sweat and other bodily fluids which may cause behavioral reactions in others.

A sixth sense.

Some researchers believe that pheromone communication might explain "love at first sight;" how we get "bad vibes" about some people and have "chemistry" with others; the phenomenon known as menstrual synchrony, common in girls’ dorm rooms the world over; how infants recognize their mothers; and even how we evaluate potential marriage partners.

In the natural world, creatures from ants to crabs to bull elephants are communicating with one another through these chemical cues. Scientists are using this knowledge to good advantage, creating "natural" insecticides and "nature-friendly" strategies for controlling pests.

But until relatively recently, no one thought humans communicated with pheromones. The long-accepted definition was that pheromones cause a knee-jerk behavioral change in the animal sensing them. No change, no pheromone. Since no one could find a chemical signal that caused such an irresistible change in humans (with the possible exception of the smell of hot chocolate chip cookies), the conclusion was that we just didn’t communicate this way.

Another argument against the idea that humans communicate with pheromones was that we supposedly don’t have the right equipment. In many species, pheromones are detected by a specialized organ inside the nose or mouth called the vomeronasal organ, or VNO. And humans don’t have a VNO, right?

Right?

Researchers have looked up a few thousand noses in search of the elusive VNO in humans, and have found two tiny pits far inside the nasal cavity. Some say these pits, known to anatomists as Jacobson’s Organ, may be the long-sought VNO.

But there are problems with this interpretation. Dr. Charles J. Wysocki is a pheromone researcher at the Monell Chemical Senses Center in Philadelphia. "A functional VNO requires that nerves from this structure should project to the accessory olfactory bulb [in the brain]. This has not been demonstrated for adult humans."

But he is quick to point out that just because humans might not have a functioning VNO, it doesn’t mean we don’t communicate with pheromones. "Many species, including at least one mammal (the pig), exhibit responses to pheromonal cues without the use of a VNO. The nose has many tricks when it comes to detecting chemicals."

If this sixth sense works on a subconscious level, is in all ways undetectable, and is understood only by a select few, it’s not to imagine nightmare scenarios. A corporation showers customers with pheromones encoded with the message, "Spend $1,000." A sexual predator uses pheromone-doctored cologne to lure victims to their doom. A pharmaceuticals company combines pheromones with a genetic sample (a strand of hair would do) to create a potion the "target" simply can’t resist.

Fortunately, scientists are discovering that pheromones’ effects are not as extensive as might be feared. Indeed, there seem to be only two areas in which pheromones actually direct human behavior. However, both are of potential interest to singles.

"What we’re finding," Wysocki says, "is that there is more genetic contribution to our behavior than we like to think. Odors, and perhaps pheromones, may affect us some, for instance in choice of mates. The more we look at odors, the more we are thinking that they do play some minor role in how we evaluate others, but the effects are very subtle."

This influence over mate choice may come from pheromones produced by genes regulating the immune system. These genes are located in the major histocompatibility complex, or MHC.

Studies have shown that female mice prefer to mate with males having dissimilar immune-system genes. Such a practice prevents inbreeding (since mice with very similar MHCs are likely to be family members) and provides the offspring with a more robust immune system.

Could such a thing be at work among humans? "The question," Wysocki says, "is: can humans detect differences in MHC and do these data influence certain decisions we might make about others, like whether we would date a given person?"

It seems likely that this is so. He points to a study among Hutterites (a Mennonite sect) in which it was found that, "more often than predicted by chance alone, mates were selected whose MHCs differed."

Conclusion #1: we give off and receive chemical signals that can influence us about our relationships, perhaps even without our conscious mind ever being alerted.

If asked why you decided against a second date with someone, you might have previously said the two of you just didn’t "click." Now you can say your major histocompatibility complex genes weren’t dissimilar enough. Isn’t science fun?

The other field of human pheromone study that seems to be bearing fruit is the investigation of menstrual synchrony. This is the phenomenon in which the ovulation cycles of female roommates (and sometimes the residents of entire women’s dorm floors) fall into synch.

When exposed to the sweat of other women, cycles have been shown to be shortened or lengthened by as much as three days (or more) per month. With one roommate’s cycle moving toward the other’s by a pace of three days a month, it is easy to see how they would quickly fall in step.

(Note that these findings only apply to women not on the birth control pill, as the pill’s artificial regulation of hormones can cause a woman’s responses to some pheromonal cues to be thrown off.)

According to Dr. Wysocki, no one knows what purpose menstrual synchrony might serve. "One theory is so that females can give birth together and thus help rear each other’s offspring. Another theory is that the menstrual synchrony may be some primitive form of competition for the attentions of the ‘alpha male.’" Whatever the cause, Wysocki believes it comes from an ancient evolutionary past. "All of these are, I think, vestigial responses."

Conclusion #2: pheromones probably cause women who live in proximity to one another (and who are not taking birth control pills) to fall into synchronized ovulation cycles; but it is not known why this occurs.

But if pheromones only affect humans when it comes to immune systems and menstrual cycles, what about all those products we’ve seen on the Internet and in those cheesy ads at the back of magazines which promise to use pheromones to make us irresistible?

The Scent, for instance (www.thescent.com), is a pheromone product whose manufacturers claim is, "a perfectly legal sexual stimulant cleverly masked in a men’s cologne that when unknowingly inhaled by any adult woman unblocks all restraints and fires up the raw animal sex drive in every woman."

A fragrance called Athena 1013 is supposed to make women feel more attractive and confident, and to fire up their love life. Realm Men and Realm Women (www.erox.com) both promise to make the wearer more at ease and confident. There’s even an outfit in Japan that will sell you underwear laced with pheromone-impregnated sweat.

The idea that one could purchase something that would invisibly turn the dating odds decidedly in one’s favor could be very alluring to some people.

Unfortunately, it’s all a bunch of hooey, most pheromone experts say. These companies are notoriously reluctant to release the details of their "scientific" research, a practice which prevents others from trying to duplicate their astounding results. Those studies which have been duplicated have been shown to be flawed, incomplete, or downright bogus.

What about all the testimonials saying the stuff works wonders? "I think that is an excellent example of the power of suggestion," Wysocki says.

What began as an exotic, even frightening, mystery sense has been reduced by science to something far less threatening. We can now point to a small number of things that pheromones seem to be doing in humans, and dismiss the rest as unethical marketing.

But have we learned anything important about pheromones, anything that might improve the human condition?

"Pheromone research has the potential to make biomedical contributions," Wysocki says. "If pheromones or compounds made from them influence physiology, then there’s the chance we can harness them and put them to some good uses."

Wysocki says signs are especially good that something might be developed in the area of pheromones’ influence on women’s ovulation cycles. "If we could identify the specific compounds doing this, they could be used in fertility situations to help a couple have a child, to be more predictive about ovulation, or to prevent them from conceiving if they’re not yet ready."

If we all have this sixth sense, and if it’s influencing us on a subconscious level, why isn’t it affecting us in more ways than just MHC compatibility and menstrual synchrony?

It may be that we’re getting pheromone information all the time, but that it doesn’t make us obey. "Pheromones do not render us powerless against their effect," Wysocki says. "They just provide another set of data about a situation or decision. These data must be reconciled with everything else," such as data coming from knowledge, judgment, memory, past experiences, reason, morality, context, etc. "After all," he says, "to be well informed—using all available information and senses—is the best way to make any decision."

If pheromones are but one vote among many—and a less influential vote than, say, common sense or commitment to Christ—it begins to explain why they don’t step into the spotlight too often.

So what advice would Dr. Wysocki give to that guy whose opening line sent the girl running in fear—or to the girl who ran? What counsel would he give that would put the whole issue of human pheromones into perspective?

"Follow your nose," he says, "but remember it’s situated between your eyes, too."

Sidebar #1—Types of Pheromones

Primer pheromones are chemical cues that, when detected at any level, can affect hormone responses in animals and insects. Primer pheromones affect the onset of puberty, the success of mice to carry litters, menstrual synchrony, and surges in testosterone.

Releaser pheromones are chemical signals that elicit displays of attraction and copulation. These are the supposed "magic bullet" that will make a person instantly irresistible. The releaser pheromones of such animals as pigs and Rhesus monkeys are the "secret ingredient" in many pheromone-related fragrances.

Signaler pheromones are the most recently identified and least understood group of pheromones. Signaler pheromones simply provide information. Whether or not the animal/human responds to the information is not known, and may or may not be important. But there is information in the odor.

Sidebar #2—Catholic Church

Charles Randles works with Dr. Martha McClintock, the University of Chicago researcher who is at the forefront of menstrual synchrony study as it regards pheromones. According to Randles, a birth control measure which uses pheromones might meet with Rome’s approval.

"For a long time, the Catholic Church has been against the use of contraception as it did not follow natural law—St. Augustus is responsible for this. The Church’s position on birth control is that it ‘refutes the finality of the faculty.’ Although it may sound sophistical, many believe that pheromone-induced contraception is in accord with natural law and would be approved by the Catholic Church."

Sidebar #3—Pheromone Research Timeline

1703. A Dutch surgeon named Ruysch identified the vomeronasal organ (VNO). Later anatomists denied that people had a VNO.

1870s French naturalist Jean-Henri Fabre noted that male moths flew from miles around to visit a female moth Fabre had caged in his lab. Fabre suspected that she was emitting an odor that was luring the fellas, but he couldn’t prove it.

1930s A prominent neuroanatomist suggested that the human VNO was best thought of as an evolutionary relic, a nonfunctioning piece of leftover anatomical equipment, like the human appendix.

1959. German chemist Adolf Butenandt identified an alcohol that carried the essence which female silkworm moths release into the air to entice males to mate with them. Butenandt coined the term ‘pheromone’ and ushered in a flood of research.

1971. American pheromone researcher Martha McClintock wrote an article for Nature giving the first observation linking pheromones with menstrual synchrony.

1980s Researchers began investigating whether or not humans retained a working VNO.

1989. Dr. David Berliner, following up on pheromones’ potential effect on one’s well-being, formed Erox Corporation to market two perfumes under the Realm brand.

Sidebar #4—For Further Study

Here are some web sites to visit to learn more about pheromones and some pheromone-related products that are available online.

whyfiles.news.wisc.edu/033love/index.html—The National Science Foundation’s web site devoted to pheromones (an excellent site)

www.erox.com—Erox Corporation’s home page (pseudo-science meets marketing hype)

www.thescent.com—Official ordering site for The Scent (caveat emptor)

Copyright © Jefferson Scott. All Rights Reserved. Reprinted with permission.