People shell out millions of dollars a year to smell like something they're not, dabbing on perfume and splashing on aftershave in the eternal quest to attract their preferred gender.

But does perfume really work? Sure, a little eau de toilette makes you smell nice, but does it make you ... sexy? Will Red or Drakkar Noir weave a scented spell that enthralls the object of your desire?

Maybe, maybe not.

Indiana University psychology professor James Craig doesn't think that fragrances by themselves can make a person more attractive.

"It's pretty clear that much of peoples' responses to perfume and other smells has got to be learned," Craig said.

Smell is a very powerful memory trigger, and past associations often dictate how a person will respond to a given scent, he said.

For instance, if you're a woman who's had a rotten relationship with a guy who wore English Leather, chances are that if you meet a man at a party who's wearing the stuff, your nose will tell you to run away.

Conversely, if your first true love put on Polo before he took you out, you might find yourself subtly attracted to new men who wear that cologne.

"Culture and conditioning play an important part in how we perceive odors," agreed Milos Novotny, a professor of chemistry at IU.

For example, while most people enjoy the scents of both pizza and violets, few would be interested in a cologne that smells like a pepperoni pie. Perfumes contain scents from blooms and not bakeries because flowers are symbols for things such as life, fertility and romance in most human cultures.

But Novotny added people's reactions to perfume is more than just conditioning. There are some odors, such as the rich scent of roses or the sweet smell of ripe apples, that we naturally enjoy because of our genetic heritage.

When humans were evolving millions of years ago, those that were attracted to the lush scents of flowers and ripe fruit got a better diet and therefore had more and healthier children than those proto-humans whose malfunctioning sniffers led them to eat hard, unripe fruits or rotting meat.

The proto-humans who benefitted from their good sense of smell eventually evolved into modern humans. Although modern life has nearly eliminated the need for a sharp nose (and, indeed, over 70% of our genes for our sense of smell don't even work anymore), we've retained our ancestors' attraction to certain scents.

But Novotny added that we've apparently inherited a few other smell-related traits from our primitive ancestors.

Many animals, such as mice and pigs, exude chemicals called pheromones that they use to communicate things such as a readiness to mate. Pheromones are known to influence the behavior and reproductive cycles of other members of their species that are exposed to the chemicals.

Novotny said that while no scientist has shown that humans produce pheromones, "some pheromone-like reactions exist in humans, such as women living in dormitories getting synchronous menstrual cycles."

Because of this, Novotny said that it is possible that some substances in perfume could act like pheromones in humans and thus heighten a person's sexual attractiveness.

"Certainly, this is an area which has been insufficiently explored," Novotny said. "It's possible that the perfume industry may know more about all this than they're telling the general public."

What could be in a perfume that might act like a pheromone?

Well, pheromones, for one thing.

"I know they (synthetic pheromones) were put in Jovan a few years back," said perfumer Keith Pierson. "But to my knowledge, it was just a fad."

Pierson, who is the lab manager for Belle-Aire, Inc., added that some perfume ingredients have been derived from secretions that animals use to mark their territories. These animal-derived perfume notes include civet, castorium, and musk.

Civet is an extract from the skunk-like spray of the civet cat. Castorium comes from the peri-anal glands of beavers, and musk is derived from a gland in the genitalia of the male musk deer.

As befits their origins, these substances smell pretty foul in their normal state. But Pierson said that if they're diluted to a 10% or weaker solution, they impart a pleasant warming effect to a perfume or cologne.

Pierson isn't sure if civet and musk have an effect on humans or not, but said they definitely attract other species.

"If you put them on yourself, half the animals in the neighborhood will follow you around," he said.

Women can recognize the smell of musk whereas three-quarters of all men cannot, he said. Accordingly, most men's colognes contain musk while few perfumes do.

But those concerned with animal rights need not worry that a beaver or deer died to make their perfume, provided they buy reasonably-priced brands.

Pierson said that all but the most expensive perfumes contain synthetic versions of the chemicals derived from animals.

"The industry came out with synthetics to replace the naturals because the naturals are so expensive," he said. "Absolute civet goes for about $3000 a pound these days."

He added that the synthetics are easier to work with and lack the foul edge of the originals.

Pheromones aside, perfumes do smell nice, and many of us will enjoy them even if they don't help us get a date. But people should remember that shopping for perfume or cologne is very much like shopping for clothes: you've got to try them on to see if they fit. And, if you want to be sexy, wear just a little: you should be bathing with water, not cologne. Fragrance isn't a suitable cover for rancid body oils and fermenting sweat.

"Body chemistry makes as much difference in the fragrance as the original ingredients," said Harry Hugar, a perfumer at The French Connection in Bloomington. "Probably, if you had twenty women in an office who were wearing Giorgio, only three of them would smell alike."

Because of this, it's not a good idea to try to buy perfume for somebody else, Hugar said. Gifts of perfume can also backfire by triggering allergies or bad memories.

"You yourself may like a fragrance, but a close friend of yours won't even be able to wear it," he said.

And finally, when you combine body chemistry with the pheromone mystery, it may be that the most alluring fragrance you can wear is the one you make for yourself.

This is a slightly-expanded version of a story I wrote for the Indiana Daily Student