There is a great sweep to humankind's ascent from brutishness: First came the mastery of fire, then the burial of the dead, the planting of crops, the weaving of cloth, the smelting of iron from the earth, the great movements of organized religion, industrialization, computerization, until finally we reached the point where we could all afford to forget how to smelt iron and instead focus on fashion questions, such as whether we look good in certain floral patterns.

"I told her I wanted a yellow cardigan, and she got me a cream cardigan with flowers on it. I don't do flowers. I do solids," says a woman named Vicki from Alexandria. She's walking into Hecht's at the Landmark Center mall on the day after Christmas, returning the gift she had so graciously received a day earlier from her stepmother.

Christmas is a time of consumer gorging that results in an inevitable dyspepsia. If Dec. 26 had its own sound effect it would be HAWWRROOOOF as millions of gifts are purged, usually merely exchanged for something similar, but often rejected outright, such as the "ring watch" that Danielle Bartoe of Reston got from her younger brother. It's a watch that you wear on your finger, like a ring. It cost $23.

"I thanked him very much for the thought," Bartoe says.

So there is an extraordinary sight on this day: people carrying giant bags of retail products into the stores, a coals-to-Newcastle sort of thing.

This may be the flip side to the explosion of merchandise: As the selection grows, so does the selectivity. Americans may have fallen behind the Japanese in the classroom and the factory, but we're geniuses in the mall.

For example, there's the mother-daughter combo of Peggy and Marianne Helms of Springfield, burdened with nine presents that they are returning to Landmark Center. Marianne is taking back a purse, two shirts, a tie, a tie rack and some Estee Lauder Micro-Moisture Bar Cleanser for Normal to Dry Skin. "I use a different formula," she explains. "I use Estee Lauder regular Beauty Bar for Normal to Dry Skin."

It's gotten to the point that people can't even keep presents that they purchased for themselves, if there's popular dissent. Bonnie Yezzi of Springfield bought herself a sweater that featured green leather fringe -- like the stuff that dangled from Elvis during his Vegas days. But when she opened it at Christmas the family gave it the thumbs down. She is back at Hecht's Wednesday morning.

"I don't like the green fringe," says daughter Holly Mays.

"I like it myself," says Mom weakly.

"No," says the daughter.

Those who say there is no such thing as progress should consider the demise of the Returns line at department stores. It used to be that every store had a window marked "Returns" in some dusty back corner, and people would find themselves in the kinds of queues we now associate with Leningrad homemakers shopping for beef. The process was fundamentally antagonistic: Unless you could prove otherwise, it was assumed you had obtained the article in question through strong-arm robbery. Lynn Tikkala, manager of the Bombay Company at the Pentagon City mall, recalls: "You used to be able to expect a fight with somebody who was totally illiterate."

The second disincentive to returning things was a purely social consideration. To return a gift was almost unthinkable. Irene Kleeberg, spokeswoman for the National Retail Federation in New York City, says, "When I was growing up it wasn't polite. If someone gave you a present you suffered with that present."

But that was the age of simple things, when merchandise came in relatively few shapes and sizes, when a blender was a blender. Now there are more kinds of blenders than species of beetles in the Amazon. Consider the case of Aide Alvarez, whose son Tony gave her a girdle. But the wrong style of girdle. "He doesn't know how to get the right thing for me," Alvarez says, noting that she prefers a shorter cut in the hips.

The stores play along. The "smart stores," says Kleeberg, don't even require a receipt these days, and many don't even insist that you exchange the returned item for another. "This shocks me, but more stores are willing to give you actual cash."

Paradoxically, these liberalized rules pay dividends to the stores. Routinely, people returning gifts will use the credit, plus their own money, to buy something more expensive, maybe something that some slightly richer or luckier person has just rejected. In this way, shoppers move up the food chain, until eventually a girdle becomes a new Chevrolet.