BACK IN 1938, an article on The Psychology Of Clothes was published in an American journal. "Not even the cultural forms assumed by man's most elementary vital activities, such as nutrition and reproduction, are so directly and so consequently interwoven with human life and the human body as dress is," wrote the author Ernst Harms. It's a convoluted sentence, but I think what Harms was getting at is this: clothes matter. Not just for the obvious warmth they bring, but for that greater warmth, the warmth of human kindness, that a well-judged outfit will attract, versus the boney chill of human disdain brought on by some particularly unsightly combo. Between the two extremes is a lukewarm middle ground on which most of us walk, wrapping 95% of our body mass in clothes that, with any luck, are not too offensive to those around us. In most cases, they will be culled from the off-the-rack cack that limits our body shapes to Small, Medium or Large.

But patterns still matter. Colours matter.

Materials matter. Years oftelly-watchinghave taught us the basic rules: kick your boss's door down and you better be wearing your power suit; start a revolution and you'll need khakis and a beret with a star on it. But an age-old conundrum persists: are you hard because you wear a shell suit, or do you wear the shell suit because you are hard?

For men, as ever, there is less guidance on such issues than for women, which seems both a blessing and a curse. But there are certain rules of thumb: looking cool is directly proportional to how close you can get to the brink of stupidity without falling over; having style means going some distance to look like others, only better, and with a nicer inside-leg. Money helps, no doubt, but offers precious little protection from yourself.

But I can help. I'm going to be your fall guy, a walking morality tale, a parable for modern times. I am taking three looks onto the streets of Glasgow - let's call them Boring Boy, Loud Boy and Leather Boy - to assess how kindly, or otherwise, I am treated.

My manner, as far as possible, will remain unchanged from guise to guise. I will have my hairometer: not a tool as such but the vague awareness that hair-touching by females often indicates attraction, or at least mild interest; and that an over-the-shoulder hair flick represents the same, but with more lust. I will visit a car showroom, with a fictional £4000 to spend on a second-hand car; a wine shop to ask for a wine recommendation; and a designer clothes store to ask for sartorial advice and assistance. I will be armed with near identical questions and ample chutzpah in each of the three guises. I am going undercover on behalf of the nation and wearing my gratefully borrowed clothes.

BORING BOY Nothing on the journey to the trendy store suggests that i am attractive to women, men or dogs'

Had I not consciously side-parted my hair, it may have done so itself. I breathe deeply to counteract the feeling that all life is draining out of me. The sky is grey, my pullover baby-blue. At Machargs car showroomonGlasgow's south side, the doors slide open. The rubber soles of my loafers squeak on the concrete floor but I have the feeling that no-one can hear or see me.

A song by Cher belts out on the radio, making me twitch. Suddenly I feel like throwing some shapes and realise the latent Dad Dancing gene has been activated prematurely.

Robert, the salesman, is behind a desk. I'm stood in front of him long enough to read his name badge forwards, backwards and upside down before he notices me.

"You're looking for something reliable," he says, crunching figures on the computer. "Nissans are very reliable." I sit, near invisible. "The engines are bulletproof. I've got smaller cars depending on how low you want to go."

"It's more a runabout I'm looking for."

"Something to get you from A to B." We are both in the realm of pure cliché, our minds numbed by my shirt and V-neck combo, our brains garroted by the legs of my trousers.

"This one's three-and-a-half grand," says Robert. "Sorry, it's only three grand." He rubs his face. "I've lost the plot here." I'm working the opposite of a snake charmer's magic. I ask if I can see the cars in the flesh, given that I would like to buy one of them. I have inherited £4000, after all, and want to spend it on some wheels.

"Sure," says Robert. "Sure." He walks me slowly to a ramp leading up to a succession of floors. I'm expecting the hard sell, an arm up my back and some pressure to sign on the dotted line. "Everything's priced up there," he says. "The Ka you are looking for is on the first floor, the other is on the top deck."

"Have you got other people to see just now?" I ask.

"No," he says. "It's just that ..." He wanders off, content.

In the supermarket the first and only woman I see touching her hair stops when she catches sight of me in the corner of her eye. She looks at her Turkish Delight, and then at me, and then back at the Turkish Delight. Its wrapper is so bright and exotic, unlike mine. The attendant at Victoria Wine is happy to help with a recommendation, but I am uncomfortable. My voice, which sounds strange even to me, is growing slower, more sonorous, like an oilman from Texas via Aberdeen. But my clothes are doing most of the talking. Not only do they feel mediocre but they seem to be inspiring mediocrity in others.

"I think the best middle-of-the-road one is here," says the assistant, holding forth a generic Rioja. I haven't specified a price but the wines I'm shown are all around £5, their grapes no doubt crushed by the corn-riddled feet of some other Mr Average. "Pino Grigio and Sauvignon Blanc are simple and non-offensive," he says. "They're both really safe choices." Like me, he might as well have added.

Nothing on the journey to the trendy Cruise menswear store in the Merchant City suggests that I am attractive to women, men or dogs. People, when they look up at all, gaze into the middle distance, right through me.

On the shop floor there is only the assistant Leigh and myself. I explain the obvious: that I am looking for help.

"What is it you normally wear?" she asks.

"Like this."

She clears her throat. "Like this?"

I follow her around the shop floor, hands outstretched, waiting for clothes to be put on my rigid arms: a very nice Paul Smith cardigan and navy trousers, a nice pair of Hudson shoes. "They're key pieces," says Leigh. "They can be mixed and matched with anything."

"What do you think of my look as it is?" I ask. "Be honest."

She laughs slightly but not unkindly. "It's quite plain," she says. "You could maybe get clothes that express your personality a bit more, rather than sticking to the stuff you feel safe in. You obviously like your V-necks but you could push the boat out a wee bit, maybe experiment with colour. Cravats are coming back in." She shuffles off to fetch one. I feel something akin to love, and certainly deep gratitude. Being accepted never felt this good. "Even this waistcoat," she says. "That would look really cool on you."

LOUD BOY THE NU RAVE LOOK WAS BAD ENOUGH IN THE 1980s AND NOW FEELS CRIMINAL'

Rain pelts my head in the east end of Glasgow. A sign on a wall, Jesus Loves You, is wrapped in heavy barbed wire. I can actually "feel" the fluorescent orange of my T-shirt, which is to say a sickly, itchy and slightly shivery heat spreading like a rash across my torso. The Nu Rave look, invented by magazines like NME, promulgated by bands like Klaxons and reinterpreted by suckers like me, was bad enough in the 1980s and now feels borderline criminal. The mineral wash skin-tight purple jeans restrict my movement as I enter the Evans Holshaw car showroom reception. A woman is on the phone but covers the receiver with her hand and bursts out laughing. "You must have been sponsored to do that," she says. "You couldn't possibly walk around that bright." She laughs so loudly that a man in an adjoining office peeks his head round for a look.

I am nervous, a little hurt, and taken aback. "I just wanted to speak to someone about second-hand cars," I say.

"Right, I'll get someone." She buzzes through to the main showroom, returns to her phonecall, and then covers the receiver again. "Is today a daft day? You don't walk around like that all the time do you?"

The salesman, Derek, clocks me through the glass doors before coming in to shake my hand and his poker face is a joy to behold. We walk together around the forecourt, discuss prices. Then Derek leaves me to it. From the corner of the lot I hear laughter and see Derek and a colleague. Are they laughing at me? The second of the two, Scott, comes over. "Why don't you follow me into the showroom, sir, so I can show you what we've got."

The showroom is a combination of bright lights and huge open space. From behind, it seems as if Scott's ears are raising, as if he might be pulling faces at his colleagues, most of whom have stopped what they were doing to look at me. Of course, he might be doing nothing of the kind. He sits me down and disappears for what seems like an age. It's difficult to look up. It feels like my red visor has suddenly gained weight and is pulling my face to the floor.

Finally, I am taken outside and shown a very bright, uber metallic Ford Ka, which must seem right up my futuristic street. If indeed there are streets where I am from. "What's that colour?"

I ask.

"Aquarius," says Scott. "Do you like it?"

Back on the road, a man with an Alsation tutts loudly as I pass. At a bus shelter outside the bingo hall, a girl pokes her head in to ask, confusingly, if I'm the Real Radio Renegade. An elderly lady tugs my arm and says: "I think you look great, son."

In Peckhams, the assistant surprises me with his recommendation of an "easy-going" red that seems to clash with my uneasy-going look. It could be the low lighting, or pure objectivity on his part. But when he starts brandishing an Australian white with a "very peculiar taste", and another that's "incredibly fruity" we both know what he's really talking about.

In the city centre, I try to engage people's eyes, but they're not interested. Only the cool kids look at me, and seem to recognise me, but then discard me again just as quickly. For some reason, the 1980s entertainter Timmy Mallett comes to mind. I feel "wacky" in the most painful sense, almost as if I'm "wacking" people in the face with my gold lamé jacket, and they are "wacking" me right back.

The floor staff in the Emporio Armani shop split like pool balls when I enter. All I can do is look at labels, pretend to be shopping, lift the occasional tie up to the light. The intrepid assistant Scott edges nearer. I tell him I'm looking for something to complement my outfit.

"Right, OK, OK," he says. Other shoppers look at me in amazement. Scott leads me though rails, racks and shelves of expensive Italian designerwear, knitwear and leather. It could be my imagination but he seems a little flustered. He stops next to a white mannequin with a blue grandad collar shirt for £115 and his professionalism is truly commendable.

"This one's brand new," he says, "but to go with your purple jeans ..." He studies those jeans, weighing them up. "I like the gold jacket," he says, "though I'm not sure if the shirt would go with it. But I do like the gold jacket."

LEATHER BOY the colour scheme works wonders, except it seems to create greed. one cake isn't enough'

I'm notching up hair-touching women like the death count in Rambo. When I look, women look back. When I smile, women smile. Other men back off when they see me and small children check their reflections in my shoes. This is my city. I control it. Truth be told, the world through my Roberto Cavalli aviators looks peachy. My only fear is that I will hit a banana skin, go head over heels, and rip the elbows out of the Gucci bomber jacket, or get the Alexander McQueen skinny tie caught in the door of a passing bus. Safe Boys and Loud Boys are of no interest to me now. The doors of the Ralph Lauren store open easily for my entrance, as if they have been specially greased. The two female assistants give a L'Oreal style hair flick, and immediately begin grooming their locks. The third assistant - a bearded male - does the same. It is he who approaches me first. I tell him that I want to change my look.

I follow him up a set of stairs, where he takes things off racks before replacing them hurriedly, as if everything he can think of is inappropriate. "We're quite casual in this store so there's not a lot of going-out stuff," he says. "A lot of it is holiday wear. We've got lots of shirts and things. Some of them are quite big."

Quite big? I'm confused. I never mentioned going out. "It doesn't need to be for a party," I say. "Maybe just for going to a friend's house." The words make sense. My outfit makes sense. But the two things together seem to jam the mind of the helpful assistant. "Most of what we have in the way of trousers tends to be chinos, and occasionally jeans," he says. He opens a drawer containing a selection of ties, explains their shape, and then shuts it again. I decide to browse for a while single-handedly.

After some time, I approach the most hair-touching of the two female assistants and say hi. "Can you suggest anything to go with this outfit I'm wearing?" I ask.

She blushes slightly, touches her hair. The cogs are turning, and she seems genuinely happy to help, but ultimately can't. "I'm sorry," she says. "I can't think of anything."

The male assistant comes bounding down the stairs just as I'm leaving. "We're getting a really nice new range in on Monday," he says. "Lots of blacks and whites."

That's the colour scheme I'm already wearing and it seems to be working wonders, except that it also appears to be creating greed. At the Tinderbox coffee shop, one cake just isn't enough. I must have two, and the most expensive ones, and with cream. And the best herbal tea. And ...

At Oddbins, the service is friendly, comprehensive and tailored to a client such as myself. The clarets are "jammy", the Shiraz is "very rich", the Cabernet is "really silky". The price of wines I am recommended range from £17.99, for a bottle of Saint Julien, to a lowly tenner for a bottle of Penalolen, which seems to tally with the Leather Boy look: "Very zingy," says the branch manager. "Very complex and intense."

Maybe it's the hand-stitched buttons on my shirt, but Andy, the car salesman at Arnold Clark on Garscube Road, keeps looking at my chest. The situation is the same: I have around £4000 to spend, and want a recommendation for a second-hand car. What is different is that I am met with handshakes and well-meaning smiles almost instantly.

Andy shows me a Corsa - "just under four grand" - and a Clio at "three-and-a-half", before the prices start creeping up. "Another Corsa here," he says. "Just a little over four grand."

But we both know this is foreplay, that there is only one car here for Leather Boy. "That's an Astra Bertone convertible," says Andy. The sleek blue model, in the context of those around it, cuts a dash. "They don't make these any more."

At £7480 it's a little beyond my reach but - in contrast to the response to my previous guises - credit is immediately offered. "If you're interested, we'll chuck the details into the system," says Andy. "It's all based on a 100-quid deposit. It's easy."

So easy, in fact, that it makes me feel sorry for my previous incarnations, who had a harder time of nearly everything. And sorry, when I think about it, for Leather Boy too. Sure, there are physical consequences to clothing - countries have probably been invaded more than once because of a dictator's ill-fitting underpants - but it's the superficial side that really stings, the way people judge you, and the thought of a tomorrow without my blessed Gucci props.

Andy shakes my hand, all smiles and hope of future transactions. But the jacket must go back to the store now, and with it an impression of me that is fleeting, already gone.