The major difference between a male and a female is the way each gets chili out of a can.

He holds it high above the pan and shakes it until the chili splats all over the stove -- or into the pan, if he's lucky.

She removes the chili with a spoon.

Why doesn't he use a spoon? Because, lacking a bear at the cave entrance, modern man must test his manhood as best he can. Also, he would have to wash the spoon.

A variation on this macho challenge is to remove the paper label and carefully balance the can over the burner. That way -- barring disaster -- he won't have to wash the pan.

As a long-standing member of a POSSLQ, I consider myself an expert in these matters. A POSSLQ (pronounced posselcue), as defined by the Internal Revenue Service, is Person of Opposite Sex Sharing Living Quarters. For the past dozen years I have rented a spare bedroom to a series of male college students. Studying the male of the species has become my chosen field of continuing education, begun with a husband and son.

We POSSLQs share the kitchen, bath, breakfast nook and television, not always simultaneously.

Although the ritual of chili removal has emerged as a prime gender difference, I would rank Instant Replay in second place. The phenomenon has grown out of watching sports on TV. It translates into real life as his inability to hear anything she says the first time around.

To wit:

SHE: This morning I saw an awful accident on the Beltway. A tractor-trailer overturned and a car ran into it and caught fire.

HE: Your car caught fire?

SHE: Not my car. The car ahead of me.

HE: Did it run into a guardrail or something?

SHE: No. It ran into the tractor-trailer.

HE: What tractor trailer?

SHE: The one that overturned.

HE: A tractor-trailer overturned? Where was this? On our street?

SHE: On the Beltway. I told you.

HE: No, you didn't. You just said something about a car catching on fire.

Too late, she realized she should have run the Instant Replay immediately following the first question. By now, his attention span has run out, and he has flipped on the TV.

Another difference between male and female is that she thanks him for taking out the trash. He creates more trash than she, with his disposable pizza pans, pot pie tins, giant milk cartons and empty six-packs. So why should she thank him for taking out his trash?

He tells a joke. She laughs like a fool, even though she's not sure she gets the point.

She tells a joke. He stares at her, deadpan, and says, "I don't get it."

A woman tends to be intuitive, a man logical. For example, she asks, "Don't you think it's a bit risky to put that full glass of milk on top of a plate of hot dogs?"

"I know what I'm doing," he says.

Three steps into the living room, and the glass falls over, spills the milk, and breaks. "That glass must have had a rounded bottom," he says.

Men have an innate ability to ration toilet paper down to the last two sheets, but are incapable of changing to a new roll. This talent is related to their competence at judging how much gasoline it takes to get home on empty when she needs to borrow his car.

Then there's the trouble with finding things. He asks for the Scotch tape. She tells him it's in the top right-hand drawer of the desk in the den.

"It's not here," he says, five minutes later. He's looking in the lower left-hand drawer of the china cabinet in the dining room. When she leads him to where she had said it was, he asks, "Why didn't you say it was here?"

Or he might go to the right place, stare blindly at the tape in the drawer, and insist, "It's not here."

On the other hand, there are problems he can solve that she had thought insoluble. The leaky garden hose, for instance.

She thought it was the nature of hoses to leak. Her hose had always gushed fountains of water at the spigot connection, and it had never bothered her, because, she figured, that's what hoses do.

One day she turned on the hose, and as she did her habitual quick-step to avoid a full drenching, was amazed to find the connection was no longer leaking. Being a female, she had to tell somebody about this miracle immediately, so she ran to the POSSLQ.

"The hose has stopped leaking," she proclaimed with innocent joy.

"Needed a washer," he said simply.

She was not only grateful, but also secretly in awe of the fact that he had never mentioned fixing the hose. She would have told him in no time flat -- and expected praise for the deed.

A man can make a woman feel like a blithering idiot when she praises him for doing a "routine thing," like repairing a broken axle on his car. But his pride can be mortally wounded when she fails to recognize creative genius. It's hard for a woman to know the difference.

"Have you flushed the toilet lately?" he asks cryptically. When she protests that that's a strange question, he looks crushed, and asks her to accompany him to the bathroom, where he shows her how he has fixed the float in the tank with a twisted wire coat hanger. She should have noticed.

Also, because of his superior large muscle development -- a fact of nature, although some are more endowed than others -- he is better than she at carrying old four-poster beds to the basement. At the same time, he is more prone to psychological injury when she questions the wisdom of transporting headboard, footboard, slats and frame in one trip. Under one arm.

And yet, when a woman hears funny noises in the night, or gets a flat tire, or the hot water heater blows up, or she needs someone to tell her which way to turn the clocks for Daylight Saving Time, what she wants is not another woman, but a man.

It's just that she wishes he would spend as much time trying to understand her as she spends trying to understand him. At least equal time with figuring Sunday's lineup of the Dallas Cowboys. And when that day comes, and the gender gap closes, and he can read her mind . . . I'm booking the first flight to Mars, with a one-way ticket.