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The Pheromone Revolution
by Jim English
In the1870s the noted French naturalist Jean-Henri
Fabre noted that male moths were flying for miles around to visit
a female moth caged in his lab. Fabre speculated that the female
moth was emitting a chemical scent that was attracting the males.
Almost a century later, in 1959, the German chemist Adolf Butenandt
ushered in the age of modern pheromone research when he successfully
isolated the active chemical, bombykol, that proved so alluring
to male moths.
Noted author Lewis Thomas examined the powerful
effect of this remarkable chemical messenger on the male moth in
his short essay, “A Fear of Pheromones.”
"The messages are
urgent, but they may arrive, for all we know, in a fragrance of
ambiguity. 'At home, 4 p.m. today,' says a female moth, and releases
a brief explosion of bombykol, a single molecule of which
will rattle the hairs of any male within miles and send him driving
upwind in a confusion of ardor.
But it is doubtful if
he has an awareness of being caught in an aerosol of chemical
attractant. On the contrary, he probably finds suddenly that it
has become an excellent day, the weather remarkably bracing, the
time appropriate for a bit of exercise of the old wings, a brisk
turn upwind. En route, traveling the gradient of bombykol, he
notes the presence of other males, heading in the same direction,
all in a good mood, inclined to race for the sheer sport of it.
Then, when he reaches his destination, it may seem to him the
most extraordinary of coincidences, the greatest piece of luck:
“Bless my soul, what have we here!”
Attraction, courtship and reproduction are among the most beautiful,
complex and baffling of all human interactions. Why are we attracted
to one person, but not another? Do we really fall in love at first
sight? And how do we know when the “chemistry” is right?
The processes that govern how, why and with whom we fall in love
have eluded and frustrated artists, poets, philosophers and scientists
through recorded history.
Now, modern research is beginning to shed light
on some of the mystery surrounding sexual attraction. Researchers
and scientists are now convinced that chemical signals, invisible
to our five normal senses, play an important role in not only how
we select a mate, but also whether we can bond and remain with that
partner over a lifetime. And as it turns out, the long sought path
to the human heart may be right under our nose.
Modern advertising employs an almost obscene range of erotic imagery
to grab our attention — and for good reason. Millions of years
of selective evolution have given modern humans a brain that is
hard-wired to respond to visual sexual cues. Consequently, when
we search for a prospective mate our initial selection is based
on perceived visual attributes such as attractiveness, symmetry,
fitness, health and social status. Once a suitable prospect has
passed inspection and been allowed to approach to within arms’
length, a new set of biologically produced chemicals begin to exert
a subtle yet profound effect on our desire. These chemicals, called
pheromones, are sexual messenger molecules produced to convey a
subconscious message of sexual interest and intent.
In the 1960s a group of anatomists at the University of Utah began
to investigate the chemistry of human skin using cells recovered
from used arm and leg casts. During the course of their work one
of the researchers noticed something unusual — when vials
containing these chemicals where left open, the previously contentious
and aggressive demeanor of the laboratory researchers began to give
way to a cheerful sense of good will and camaraderie. Later, when
these same vials were closed, the scientists drifted back to their
previous habits of competition and isolation.
Over the next 30 years scientists embarked on
a search for this odorless chemical with the power to turn a group
of grouchy lab workers into a cooperative and energized team.
The word pheromone comes from the Greek words Pheran (to transfer)
and Horman (to excite). Pheromones are complex organic compounds
utilized by all animals, from protozoa to the higher primates, as
a means of communication. In complex animal societies specialized
pheromones facilitate the cooperation of individuals for a number
of functions. Some examples:
- Insects such as ants and bees use alarm
pheromones to trigger an instant and violent response if a colony
comes under attack.
- Rabbits release dispersion pheromones to demarcate
territorial zones and to disperse members of the group in the
presence of a threat.
- And boll weevils produce aggregation pheromones
to inform others of the presence of food or new habitats for colonization.
While specialized pheromones can serve a range
of species-specific purposes, sexual pheromones play an identical
role in all species — they convey sexual excitement and intent
to potential mates.
Garden variety odors and scents are detected by cells within the
nasal cavity by the main olfactory epithelium (MOE). Pheromones,
on the other hand, are perceived by a separate accessory structure
known as the vomernasal organ (VNO). In 1813 the Danish anatomist
Ludvig Jacobson described his discovery of this organ, located in
the nasal cavity of mammals. The VNO has been shown to be exclusively
connected to specialized centers of the limbic system.
Once believed to be a purely vestigial organ in
humans, research has confirmed the existence of the VNO in humans.
In one study in 1958, histological examination of the nasal septum
revealed the presence of vomeronasal cavities in approximately 70
percent of all adults. Later, microscopic examination in 1991 was
able to clearly identify the presence of vomeronasal organs in 100
percent of adult subjects. This lead to the conclusion that the
VNO is present in adult humans, and that this specialized chemosensory
organ has evolved to do one thing: detect human sexual pheromones.
Researchers have shown that the human VNO is connected directly
to the limbic system, that part of the brain that is responsible
for exploration, flight or fight, for identifying with the environment
and reacting to it. The limbic system is also responsible for controlling
emotional and behavioral patterns. As William Regelson, M.D., describes
it, “You can tell when someone is paying attention or reacting
to you with a deep connection, because their eyes glow. This is
because they connected with their limbic system. You’re really
limbic when you’re in love — your eyes glow. If you’re
a religious fanatic, your eyes glow. If someone is in love with
you, you can tell, because their eyes glow — they’ve
formed a deep limbic connection with you. And this is why the eyes
are, in a very real sense, the seat of the soul. And I think that
pheromones are really the key limbic stimulants involved in love
and lovemaking.”
Once the presence of a working pheromone receptor (VNO) in humans
was proven, the next step lay in understanding how pheromones actually
work on humans. Unlike insects, humans do not drop everything at
the first whiff of a few delicious carbon molecules and assume the
mating position. But for all our evolved sophistication and Byzantine
sexual cues and responses, an accumulating body of data has firmly
established the working presence of these stealthy chemicals.
One of the first indications that humans produce
and respond to pheromones was the discovery that women living in
close proximity tend to synchronize menstrual cycles within a few
short months. Researchers then discovered that chemicals produced
in the armpits of females at different phases of the menstrual cycle
influence the timing of their cycles. In a 1988 study by Stern and
McClintock, researchers collected underarm perspiration from women
at specific intervals during their monthly ovulation cycles. After
the samples were treated to render them odorless they were applied
above the upper lips of a second group of female volunteers. The
results were that the onset and length of the ovulation cycles of
the second group of volunteers were altered to synchronize with
the first group.
Investigators speculate that the synchronization
of menstrual cycles is an evolutionary trait with two important
purposes: First, by closely timing their menstrual cycles, women
would reject all the men of their group at the same time and force
them to go out to hunt. Second, by synchronizing the menstrual and
birthing cycles, women would give birth at the same time, allowing
them to optimize available resources for the care and protection
of their young.
“This study, I think, really is the first
definitive study that shows that humans have pheromones,”
said McClintock at the conclusion of the study. “We still
need to know whether we use them on a regular basis, but they are
there.”
It is now recognized that pheromones play a role in conveying the
genetic makeup and health of a prospective reproductive partner.
Major histocompatibility complex (MCH) genes are among the most
diverse of all genes, constituting, in essence, a genetic signature
of the individual. MHC genes help the body to recognize its own
healthy cells, to identify invading pathogens and to reject foreign
tissues.
MHC genes also give each individual a unique odor
that can be detected. Among mice it is well known that MHC genes
play an important role in mate selection. Inbred mice, identical
except for MHC genes, prefer the odor of closely related nest mates.
Once they enter puberty these mice show a marked preference to mate
with mice whose MHC genes are most unlike their own.
Once pregnant these mice revert to their early
preferences and return to nest with males with similar MHC genes.
Scientists speculate that nesting with relatives ensures not only
help in nursing and raising the young but also confers protection
from strange and potentially dangerous males. The preference for
MCH-dissimilar mates is also seen as important for reducing the
risks of inbreeding and genetic diseases.
To see if MHC genes play a role in human mate
selection, Klaus Wedekind, a zoologist at Switzerland’s Bern
University, conducted a unique experiment involving smelly T-shirts.
Wedekinds’ team recruited 49 women and 44 men who were screened
to assure they carried a wide array of MHC genes. Each man was given
a clean T-shirt and instructed to sleep in the shirt for two nights
to thoroughly saturate the material with his scent.
The shirts were then gathered and placed in cardboard
boxes with sniffing holes in the tops. Each woman was brought into
the lab at the midpoint of their menstrual cycles and presented
with a choice of seven boxes to sniff. Three boxes contained T-shirts
from MHC-similar males, three from MHC-dissimilar males, and the
last box contained a clean shirt as a control. The women were asked
to smell the boxes and rate them as smelling either pleasant or
unpleasant. The researchers discovered that the women preferred
the scent of men with dissimilar MHC genes. Many of the women also
commented that the MHC-dissimilar shirts reminded them of their
boyfriends, both past and present.
Cosmetics purporting to contain pheromones have been around for
a number of years, each promising to increase one’s sexual
attractiveness and prowess. In fact many of these cosmetics, packaged
as perfumes and colognes, did contain a real pheromone, called androstenone.
Derived from pig saliva, androstenone has been shown to be extremely
effective pheromone, causing an almost immediate and uncontrollable
mating reaction — if you happen to be a pig. And though one
may argue that humans often behave in a piggish manner, thankfully
we do not respond to porcine pheromones.
The real breakthrough in human pheromones had
to wait until 1986 when researchers at the Monell Chemical Senses
Center in Philadelphia isolated and synthesized the first working
human pheromone. The result of this research is now available as
the first human-derived, clinically tested pheromone, EroScentTM.
EroScent™ is packaged in a convenient roll-on applicator that
is used to gently apply a small amount of human pheromone directly
under the wearer’s nose. Only a small amount of EroScent™
is required, as it takes but a few molecules to activate the limbic
system. Since pheromones don’t have to travel through the
bloodstream, EroScent™ begins to act immediately.
The human VNO has been shown to be connected directly
to the limbic system, that part of the brain that is responsible
for exploration, flight or fight, for identifying with the environment
and reacting to it. By applying EroScent™ under the nose one
is directly stimulating one’s own limbic system and keying
into the region of the brain that controls our emotions, mood and
desires.
Modern humans possess a highly refined sense of personal hygiene.
We bath or shower almost daily, removing any trace of our natural
pheromones. We drench ourselves in deodorants and fragrances to
further mask any natural scent. And as if to add insult to injury,
we cover ourselves from head to toe in clothes, blocking the very
skin that produces our natural pheromones. In short, we do everything
within our power to hide or mask our sixth sense and short circuit
our ability to communicate chemically.
EroScent™ gives us back the ability to re-establish
a sense of chemical comfort and well-being with those close to us.
The pheromones in EroScent™ work primarily by stimulating
the limbic system of the wearer. While there is a secondary effect
on members of the opposite sex, most of the effect takes place in
the person wearing EroScent™. People using EroScent™
have reported a wide range of benefits, including:
• Elevated mood: Women
in particular seem to suffer a loss in self-confidence and sexuality
following age-related drops in pheromone production. Both men and
women who describe themselves as feeling depressed and “down
in the dumps” report an improved sense of well being and a
more positive and energetic outlook on life when wearing EroScent™.
Researchers, excited by the therapeutic benefits of human pheromones
in restoring sexuality and improving self-esteem, are also looking
into using human pheromones to alleviate panic attacks and mood
disorders.
• Enhanced sexual attractiveness: In a double-blinded
study testing the human pheromones contained in EroScent™,
20 women received pheromones three times a week. The women receiving
the pheromones, applied topically, reported a significantly higher
rate of sexual contact with men than women using a placebo.
A second double-blind, placebo-controlled study conducted in 1998
found that men who received human pheromones tended to also have
more sexual contact with women than the men who applied the placebo.
• Enhanced romantic relationships:
EroScent™ works via the reproductive endocrine system to enhance
existing sexual cues and improve chances for enjoying a satisfying
romantic life. One man reported that he and his spouse, caught in
the doldrums of a long-term marriage, had drifted apart and were
only having sex on average about five times per year. “Since
I’ve been using the pheromone straight, it’s five times
a week!”
• Enhanced working relationships:
A journalist researching human pheromones decided to try EroScent™
to test the results for herself. “I immediately noticed that
the people I work with were looking at me and smiling more than
usual. I finally realized that it was me — that I was making
more eye contact with them and sending a message of confidence I
didn’t normally project.”
To test the effectiveness of pheromones in real-life, ABC News conducted
an impressive if somewhat unscientific test in March of 1988. Two
sets of identical twins — two sisters and two brothers —
were taken to a popular New York bar. Human pheromone was applied
to one of the twins in each pair, while the other got plain witch
hazel. Neither twin knew what they received. The only rules for
the test were that they were to trade places throughout the evening,
and they couldn’t make the first move toward contacting other
bar patrons.
The results for the men came out about even —
a handful of women approached each of them. This isn’t unusual,
as fewer women will approach a strange man in a bar. But the results
for the women were more dramatic. Shari, the twin wearing the witch
hazel, was approached by 11 different men over the course of the
evening. But Stasea, wearing the human pheromone, was chatted up
by 30 different men, nearly three times as many as her identical
twin sister.
Shari noted that “People didn’t even
want to talk to me, and my sister got all the attention. It was
incredible, truly.” Stasea’s reaction to the pheromone
was that “They didn’t just talk, they were ENTHRALLED
with me!”
Concluding the report, ABC News Medical Corespondent
Dr. Nancy Snyderman asked “about the situation in the bar,”
to which reporter Bill Ritter said “The results astonished
us. We can’t deny what we saw happen in the bar.”
Many factors influence our attractiveness to others. Physical attractiveness,
age, health, fitness, social status and character are but a few
components known to affect one’s perceived attractiveness
by a potential mate. Only recently have researchers been able to
uncover the unseen chemistry that controls our mating strategies
— unconscious odors and undetectable odors that comprise the
human “sixth sense.” The human pheromones contained
in EroScent™ directly energize the limbic system of the wearer
to boost confidence, stimulate the libido, enhance romantic possibilities
and contribute to an increased sense of well-being.
References
1. Cutler, W.B., “Human Sex-Attractant
Pheromones: Discovery, Research, Development and Application in
Sex Therapy. Psychiatric Annals.” The Journal of Continuing
Psychiatric Education, Jan. 1999, Vol. 29, 1:54-59.
2. McClintock MK, “On the nature of mammalian and human pheromones.”
Ann N Y Acad Sci, Nov. 1998 30; 855: 390-2.
3. Wedekind C, Furi S. “Body odor preferences in men and women:
Do they aim for specific MHC combinations or simply heterozygosity?”
Proc R Soc Lond B Biol Sci. Oct 1997; 264 (1387): 1471-9
4. Wedekine C, Seebeck T, Bettens F, Paepke AJ. “MCH-dependent
mate preferences in humans.” Proc R Soc Lond B Biol Sci, June
1995; 260 (1359): 245.
5. ABC News, “Sniffing Out a Mate” from the Pulse Program.
Host Nancy Snyderman, M.D., on ABC News Saturday Night with Bill
Ritter, March 28, 1998. |
