Wondering what to wear at the holiday party to lure a new love for '09? That expensive, sequiny dress? A handsome new holly-green vest and some knock-'em-dead after-shave? Too bad fashion writers don't read science journals. Instead of just lecturing on clothing, perfume and makeup, they could draw on research from human mating for their tips on boosting one's attractiveness at holiday parties -- ones that don't involve buying a thing.

Details such as the color of the walls, who you stand next to, whether the crab cakes at the buffet run out early -- strange to say -- may change how others perceive us in small (yet potentially useful) ways. "People are differentially attractive under different circumstances," says David M. Buss, an evolutionary psychologist at the University of Texas at Austin and author of "The Evolution of Desire."

So we trawled the scientific journals to find holiday party mating strategies that draw upon this fact. Here are the fruits: arcane tips for maximizing your irresistibility at parties this month, no expensive bling required. (Apologies to some up front: Most of the experiments we found focus on the attractiveness of heterosexual women.)

Party pointers

Hang out by the spiked eggnog bowl.

"The world -- or at least people in it -- looks better after a couple of drinks," says Marcus Munafo, a professor of biological psychology at the University of Bristol in England. In a study published in the journal Alcohol and Alcoholism, Munafo and colleagues invited 84 college men and women into a lab for a happy-hour "beer goggles" experiment. Half of the participants got a strong vodka and tonic (equivalent to a couple of beers or a large glass of wine); the rest got a look-alike straight-tonic placebo.

Men who got the vodka rated photographs of women's faces as more attractive than did non-drinking men. Likewise, drinking women scored men's faces higher than did sober women. The next day, the boozy effects had faded -- except for men's rating of women, which remained high.

Why it might work: Alcohol changes how we perceive facial symmetry. In a study in a Brazilian bar, men and women, when drunk, had a harder time spotting small deviations of symmetry in pictures of geometric shapes.

Normally, our brains are highly sensitive to whether the right and left sides of faces match up like mirror images. Across cultures, we deem symmetrical faces to be the most beautiful. Women even tend to have orgasms more easily with symmetrical-faced men, research suggests. Our hearts thrill to this geometric perfection as it's a sign of good genes and overall good health, researchers suspect -- mateworthiness, in other words.

The bottom line: For maximum benefit, stay sober and keep your mate-discrimination skills in top shape -- but pour eggnog liberally for others.

Go to parties in the winter -- preferably in cold climes. Remove your coat and go mingle.

Women's bodies are never more beautiful than when they've been covered up. It's not that winterized bodies, pasty-white and plumped by holiday feasting, are necessarily more attractive. But men's opinions of them magically change when the weather turns cold and people bundle their figures out of sight.

Researchers discovered this by knocking on doors during the dead of winter in Poland. They asked men to flip through a notebook containing photographs of women -- bodies in bathing suits, face shots and bare breasts -- and rate the attractiveness of each. Then researchers tracked down the same men in the spring, summer, autumn and the following winter, asking about the same pictures.

Men loved the breasts and bodies most of all in the winter; in the summer, they gave the same photos the lowest ratings. (Opinions of faces stayed steady year-round.)

Why it might work: In the summertime, bare flesh is everywhere. As a consequence, any one body (or bosom) seen in July will probably seem less attractive than the same one seen in January, says study coauthor Boguslaw Pawlowski, a professor of anthropology at University of Wroclaw But in the winter, even blah-looking anatomy temporarily on display in a party dress instead of swathed in a thick sweater could be a sight for sore eyes. This could explain why men rated faces the same each season: Unlike breasts, faces are always visible.

The bottom line: Sadly, Southern California -- with its year-round sunshine and abundance of tanned, young skin -- might create a disadvantage in the holiday-party circuit. Women should consider trying their luck while visiting folks in Minneapolis or Buffalo.

Break out the sexy-Santa suit. And pose by the poinsettias.

"The red that women wear for festive purposes during the holiday may be having unintended effects on the males they encounter," says Andrew Elliot, a professor of psychology at the University of Rochester. In a survey of 181 men and women, he and colleagues found that when straight men see a picture of a woman against a red background or wearing a red shirt, they're more likely to want to ask her on a date, spend more money on the date and have sex with her -- than a woman surrounded by, say, blue. "They do not find such women more likable or intelligent," Elliot says, "just more sexy."

Why it might work: Red means "ready" in primate language. Some monkeys and apes advertise their sexual prime times on their skin, turning bright red throughout their vulvas, buttocks, chests and faces during ovulation. Male primates prefer to mate with these flushed females. We humans may not have red rumps, but men may be drawn to the color -- whether gleaming from lips, splashed across camisoles or in the blush on a face -- all the same, Elliot says.