Seven years ago I was living in the East Village undergoing a significantly delayed adolescence, drinking and drugging a little too much, and indulging in all the sidewalk freak-show opportunities that New York City has to offer. Back then I was hanging around a lot with a drag king I had met through friends. She used to like to dress up and have me take pictures of her in costume. One night she dared me to dress up with her and go out on the town. I'd always wanted to try passing as a man in public, just to see if I could do it, so I agreed enthusiastically.

I made myself a goatee and moustache, and a pair of exaggerated sideburns. I put on a baseball cap, loose-fitting jeans and a flannel shirt. In the full-length mirror I looked like a frat boy - sort of.

She did her thing - which was more willowy and faint, more like a young hippie guy who couldn't really grow much of a beard - and we went out like that for a few hours. We passed, as far as I could tell, but I was too afraid really to interact with anyone, except to give one guy brief directions on the street. He thanked me as "dude" and walked on. Mostly, though, we just walked through the Village scanning people's faces to see if anyone took a second or third look. But no one did. And that, oddly enough, was the thing that struck me the most about that evening.

I had lived in that neighbourhood for years, walking its streets, where men lurk outside of bodegas, on stoops and in doorways much of the day. As a woman, you couldn't walk down those streets invisibly. You were an object of desire or at least semiprurient interest to the men who waited there, even if you weren't pretty. But that night in drag, we walked by those same stoops and doorways and bodegas. We walked by those same groups of men. Only this time they didn't stare. On the contrary, when they met my eyes they looked away immediately and concertedly, and never looked back. It was astounding, the difference, the respect they showed me by not looking at me, by purposely not staring.

To look another male in the eye and hold his gaze is to invite conflict, either that or a homosexual encounter. To look away is to accept the status quo, to leave each man to his tiny sphere of influence, the small buffer of pride and poise that surrounds and keeps him. After the incident had blown over, I started thinking that if I had learned so much about the unspoken male codes after being in drag for only a few hours, couldn't I observe much more about the social differences between the sexes if I passed as a man for a much longer period of time? I was determined to give the idea a try.

First, if I was to create this man, I had to think of an identity for him. I needed a name. I hit upon Ned, a nickname from childhood that had long since fallen out of use. Practically from birth, I was the kind of hardcore tomboy that makes you think there must be a gay gene. How else to explain my instinctive loathing of dresses, dolls and frills of any kind when other girls delighted in such things?

Next, there was my appearance. The first and most important step was to find out how to make a more believable beard than the slapdash version my drag king friend had taught me years before. Ryan, a make-up artist of my acquaintance, suggested using wool crepe hair instead of real hair. I could buy whatever shade best matched my hair and always have a ready supply to hand without having to butcher my haircut. Ryan showed me how to unwind the braids, comb the strands of hair together, then cut the ends. Later, as I refined this process, I bought a men's electric beard trimmer and ran it across the tips of the hair, producing actual stubble-length pieces that, when applied with a lanolin and beeswax-based adhesive, looked like a five o'clock shadow. To help square my jaw I to went to the barber and asked him to cut my hair in a flat-top - a haircut I usually abhor on men, but which did a lot under the circumstances to masculinise my head.

Then I went to the optician and picked out two pairs of rectangular frames, again to accentuate the angles of my face. In the beginning I was so worried about getting caught - not passing - that, in order to ensure my disguise, I wore my glasses everywhere, and often a baseball hat.

Once I'd finished doctoring my head and face, I began concentrating on my body. First I had to find a way to bind my breasts. This is trickier than it sounds, even when you're small-breasted. In the end, cupless sports bras worked best. I bought them two sizes too small and in a flat-fronted style. Naked, it didn't make me a board, but with a loose shirt and some creative layering it worked fine.

It did, however, dig into my shoulders and back, especially as I got bigger. And I did get bigger. That was the next step in transforming my body. Lifting weights. Lots of weights. I consulted a trainer at my local gym, telling him about the project, and he suggested building muscle bulk in my shoulders and arms. By lifting heavy weights at low repetitions, and by eating large quantities of protein every day, I gained 15 pounds in six months. I was still a small guy by normal measures, but my shoulders were recognisably broader and squarer.

To complete the physical transformation, I went in search of a prosthetic penis that I could wear for verisimilitude as much as anything else. At a sex shop in downtown Manhattan I found a "packable softie". This item, which I nicknamed Sloppy Joe, was a flaccid member designed especially for what drag kings call packing, or stuffing, your pants. It was better than a sock and would give me, if not others, a more realistic experience of "manhood". To keep it in place I wore it inside a jockstrap. Finally, I took Ned shopping for clothes, in drag, of course. I bought him preppy, safe things such as rugby shirts and khakis and baggy jeans.

I made my last stop for Ned at the Juilliard School for the Performing Arts, where I hired a voice coach to help me learn to speak more like a man. My voice is already deep, but as with so many other things, I found that when you are trying to pass in drag, all the characteristics that seem masculine in you as a woman turn out to be far less so in a man. Using fewer words, speaking more slowly and sustaining my breath through the words all helped me to use the deeper notes in my register and to stay there.

Now I had to find some male company. Bowling was an obvious choice. It's the ultimate social sport, and as such would be a perfect way for Ned to make friends with guys as a guy. Better yet, I wouldn't have to expose any suspicious body parts or break a heavy sweat and risk smearing my beard.

It was still a daunting prospect. Any woman who has ever run the gauntlet of construction workers on lunch break will understand how it felt to walk into that bowling alley for the first time on men's league night. Those guys may not have known that I was a woman, but the minute I opened the door and felt the air of that place waft over me, every part of me did. It felt as if every pair of eyes in the place had landed on me and stuck. After standing there frozen for several minutes, I had just about worked up the gumption to retreat and call off the whole thing when the league manager saw me.

"Are you Ned?" he asked, rushing up to me. "We've been waiting for you. C'mon and get yourself some shoes and a ball."

There was no getting out of it now. It was when I began watching the men bowling that I could see this was going to be laughable. They were all throwing curve balls that they'd been perfecting for 20 years. I couldn't even remember how to hold a bowling ball, much less wing it with any precision. I was dressed as down and dirty as Ned got in a plaid shirt, jeans and a baseball cap pulled low over the most proletarian glasses I could find. But despite my best efforts, I was still far too scrubbed and tweedy amid these genuine articles to pass for one of them. Even at my burliest, next to them I felt like a petunia strapped to a Popsicle stick. Looking at them I thought, it's at times like these when the term "real man" really hits home with you.

The league manager led me toward the table where my new team-mates were sitting. Jim, my team captain, introduced himself first. He was about five feet six, a good four inches shorter than I am, with a lightweight build and oddly small feet - certainly smaller than mine, which have topped out at an alarming men's eleven and a half. He was 33, but in bearing he seemed younger. Next I met Allen. His greeting echoed Jim's - a presumption of goodwill that seemed to mark me as a buddy from the start. Bob I met last. We didn't shake hands, just nodded from across the table. He was 42 and he had a serious middle-aged belly filling out his T-shirt. He wasn't the friendly type.

They had all been playing golf and poker together several times a month for years, and Allen was married to Bob's sister. I was a stranger out of nowhere without any shared work or home life experience to offer, but Jim's social generosity gave me an in. He was a natural comedian and raconteur, easy to listen to and talk to; the most open of the bunch by far, and charming as hell.

We all usually ate junk food on those Monday nights, all of us except Bob, who stuck to beer, but let us send his 12-year-old son Alex, who always tagged along on league night, next door to the 7-Eleven to buy hot dogs, candy, soda, whatever. I noticed that no one ever tempered his speech when Alex was around. We swore like stevedores and nobody seemed bothered, including me, that a 12-year-old was within earshot.

Everything was out and above board with these guys. If they were pissed at you, you'd know it. They were glad enough to see me, but not glad enough to miss me if I didn't show. They were coming from long, wearying workdays and they didn't have the energy for pretence. Allen was a construction worker, Bob a plumber. Jim was working in the repair department of an appliance company.

None of them got much satisfaction from their jobs, nor did they expect any. There were the occasional gay or sexist jokes, but they were never mean-spirited. Ironically enough, the guys told me that I, being the worst bowler in the league by far - my average was a mere 100 - was lucky I hadn't bowled with them in a previous season when anyone who averaged less than 120 incurred the label "fag", and anyone who averaged less than 100 was, by default, a "girl".

Nothing was beyond humour, especially for Jim. He often told stories about his days at school as a kid, stories that confirmed my suspicion that he had a lot going on inside his head that had been beaten out of him on the playground. "I was one of those quiet, psycho kids," he'd say. "I never spoke. I just sat there in the corner. You couldn't provoke me to fight. You could be pokin' me with a stick and I wouldn't move. I'd just be sittin' there drawing pictures of killing your family."

One night Jim was talking about his plans for a ski trip. He wanted to find a location that had good skiing, but he also wanted some lively nightlife. "I'd like to find a place that has a good titty bar," he said.

Bob chimed in, "Yeah. Count me in on that. I'm definitely up for that." This sparked a short discussion of titty bars and how the married man negotiated them. The ski trip would offer one of the few opportunities for the boys to be boys, since their wives weren't coming along. This had to be taken advantage of, since it was clear that at least Bob's and Jim's wives had expressly forbidden them to go to strip clubs.

Despite all the dirty talk and hiding strip club visits from their wives, they would speak about their wives and their marriages with absolute reverence. It was an odd contradiction, but one that I came across fairly often among married men who talked to Ned about their sexuality.

On the first night they must have known me for the putz I was the minute I heaved the ball with both hands but when I'd traipse back to my table in fuchsia-faced shame with a zero or a foul blinking on the board, they never laid me low. I always got supportive advice. "You'll get there, man," they'd say. "You should have seen me when I started." Or, more helpfully: "Just shake hands with the pins, man. That's all you got to do. Just shake hands with the pins."

They were far more generous with me than they had any reason to be, and it was only after a couple of months when they got to know me a little better that they felt free enough to kid me now and then about how much I sucked, letting me in.

"Hey, we all got strikes this round," Bob would say, "except one. Who was that, I wonder?" Then he'd smile at me while leaning back in his chair, dragging deeply on his cigarette. I'd make a big show of giving him the finger, and we'd all laugh.

Half the time I was ashamed of myself for trying too hard, saying fuck or fuckin' one too many times in a sentence for effect, or swaggering just a little too wide and loose on my way to and from my turns, and as a result probably looking like I had a load in my pants. But then I could see all of these learned behaviours in Bob and Jim and Allen, too, as well as the remnant insecurity they were meant to disguise. As always, Jim was the most forthcoming about his stupid flights of machismo and the dumpsters they'd usually landed him in.

"I remember when I was in the army," he'd say, "and I was drunk off my ass as usual. And there was this huge guy playin' pool in the bar I was in. And I don't know why, but I just flicked a beer coaster at him, and it hit him right in the back of the head. And he turned around really slowly and he looked down at me and he said in this really tired way, 'Do we really need to do this tonight?' And I said, 'Nah, you're right. We don't. Sorry.' So he turned around, and fuck me if I didn't just throw another one and hit him again, right in the back of the head. I don't know why I did it. No fuckin' idea. And I knew when I did it that he was gonna kick my ass, so I turned around and tried to run, and I slipped in a puddle of beer and fell on my face, and he just picked me right up and bashed the shit out of me. And the funniest thing about it was that the whole time he was punching me, he kept apologising to me for having to do it." This was a source of hilarity to everyone, the stupid crap you felt compelled to do as a guy finding your spot in the scheme of things.

I could never have predicted it, but part of me came really to enjoy those nights with the guys. Their company was like an anchor at the beginning of the week, something I could look forward to, an oasis where nothing would really be expected of me.

I thought dating was going to be the fun part, the easiest part. Certainly as a man I had romantic access to far more women than I ever did as a lesbian. I could partake at last in the assumption of heterosexuality and ask out any woman I liked without insulting her. Of course, I was in for a mountain of rejections, but to be a guy I had to get out there.

I figured it couldn't hurt to enlist a compatriot for support, so I asked a friend, Curtis, to be my backup. He was perfect for the job. He was a handsome, well-built, gregarious type, secure and sensible enough not to take himself too seriously, or care much what a stranger might think of him.

Curtis had said he would nudge me when I got out of line and he spent most of our first night out together kicking me under the table. I was on a roll, eager to test my new treads. So as soon as we sat down, I picked out a couple of twentysomething women sitting at a table across the room. I gave them a few lingering looks to check their interest. I caught one woman's eye and held her gaze for a second, smiling. She returned the smile and looked away. This was signal enough for me, so I stood up, made my way over to their table and asked them whether they wanted to join us for a drink.

"No, thanks," one of them said, "we're on our way out in a minute."

Simple enough, right? A brush-off. No biggie. But as I turned away and slumped back across the room toward our table, I felt like the outcast kid in the lunchroom who trips and dumps his tray on the linoleum in front of the whole school.

"Rejection is a staple for guys," said Curtis, laughing as I crumpled into my seat with a humiliated sigh. "Get used to it."

"How do you handle it?"

"Let me tell you a story," he said. "When I was in college, there was this guy Dean, who got laid all the time. I mean this guy had different women coming out of his room every weekend and most week-nights, and he wasn't particularly good-looking. He was fat and kind of a slob. Nice guy, though, but nothing special. I couldn't figure out how he did it, so one time I just asked him. 'How do you get so many girls to go out with you?' He was a man of few words, kind of Coolidge-esque, if you know what I mean. So all he said was: 'I get rejected 90% of the time. But it's that 10%.' "

That made us both cackle and pound the table. "That's the thing about being a guy," Curtis finished. "Rejection is part of the game. It's expected."

Not only was dating one of the hardest of Ned's experiences, it was also the most fraught with deception. I decided I would out myself to anyone with whom I had more than a passing, unsuccessful, date or two. To most of the women I dated, even the odd date meant a lot, especially women who had been out roaming the singles scene for years in their mid-30s, trying to find a mate amid the serial daters.

For these women, men as a subspecies - not the particular men with whom they had been involved - were to blame for the wreck of a relationship and the psychic damage it had done them. It's hardly surprising, then, that in this atmosphere, as a single man dating women, I often felt attacked, judged, on the defensive.

Many of my dates - even the more passive ones - did most of the talking. I listened to them talk literally for hours about the most minute, mind-numbing details of their personal lives; men they were still in love with, men they had divorced, roommates and co-workers they hated, childhoods they were loath to remember yet somehow found the energy to recount ad nauseam. Listening to them was like undergoing a slow frontal lobotomy.

Weren't people supposed to be on their best behaviour on first dates? Weren't they supposed to at least pretend an interest in the other person, out of politeness if nothing else?

Certainly that's what I was doing, making polite conversation. So much so that I never expected to hear from these people again. I was boring myself. But to my surprise, many of them did contact me again - enthusiastically.

Ironically, one of the women who was the least well-adjusted, and the least graceful at dating, turned out to be one of the most important of my relationships. I had met Sasha, as I met most of my dates, through a personals website on the internet. We'd exchanged photographs and a number of emails. After a week or so of back and forth, we'd decided to get together for coffee.

That first date was lousy but the email relationship continued. Indeed, email is now central to dating. Correspondence was mandatory, even with the women I met at speed-dating events and followed up with later by email. These women wanted to be wooed by language. They weren't going to meet a strange man without measuring him first, and they weren't going to waste a meal or even a cup of coffee on a suitor who couldn't be bothered to craft a few lines beforehand. I was happy to oblige. It was rare, most of them told me, for a man to write at such length, much less to write with consideration and investment.

For a little contrast, I went on a few dates with men as a woman during the course of my time as Ned. The men I met on the internet, and then subsequently in person, didn't require this epistolary preamble, nor did they offer it. They were eager to meet as soon as possible, usually, I found, because they wanted to see what I looked like. Their feelings or fantasies would be based on that far more than, or perhaps to the exclusion of, anything I might write to them. On dates with men I felt physically appraised in a way that I never did by women, and, while this made me more sympathetic to the suspicions women were bringing to their dates with Ned, it had the opposite effect, too. Somehow men's seeming imposition of a superficial standard of beauty felt less intrusive, less harsh, than the character appraisals of women.

The women I met wanted a man to be confident. They wanted in many ways to defer to him. I could feel that on many dates, the unspoken desire to be held up and led, whether in conversation or even in physical space, and at times it made me feel quite small in my costume, like a young man must feel when he's just coming of age and he's suddenly expected to carry the world under his arm like a football. And some women did find Ned too small physically to be attractive. They wanted someone, they said, who could pin them to the bed or, as one woman put it, "someone who can drive the bus". Ned was too willowy for that. I began to understand from the inside why Robert Crumb draws his women so big and his diminutive self begging at their heels or riding them around the room.

Yet as much as these women wanted a take-control man, at the same time they wanted a man who was vulnerable to them, a man who would show his colours and open his doors, someone expressive, intuitive, attuned. This I was in spades, and I always got points for it. But I began to feel very sympathetic toward heterosexual men - the pressure to be a world-bestriding colossus is an immensely heavy burden to bear, and trying to be a sensitive new age guy at the same time is pretty well impossible. Expectation, expectation, expectation was the leitmotif of Ned's dating life.

In my mail exchanges with Sasha, I wasn't playing a role. I didn't try to write or say the things I thought a man would write or say. I responded to her genuinely in every way, except about my sex.

Our time together lasted the longest, three weeks or so in all. We had only three dates during that time, but we wrote several times a day. Naturally, during the course of all this, we talked about her past relationships with men, which, as she indicated at some length, had been less than satisfactory. I suggested that perhaps if men were so unsatisfying to her emotionally, she should consider dating a woman. To this she sent a sharp reply, something of the order of having about as much interest in lesbianism as in shooting heroin.

She had, by this time (about two dates and a week and a half into our correspondence), told me that she found Ned attractive, though she also made it clear that she was emotionally engaged elsewhere and was likely to remain so for a long time. Still, something had grown up between us in a short time and I decided that it shouldn't go any further. I would tell her the truth on the third date, which we were scheduled to have at the end of that week. I was curious to see what would happen to her supposed attraction for Ned when she learned that he was a woman. Would it evaporate?

We met for dinner at her house. During dinner I told her right out, in the blurted way our conversations tended to go, that there was something I wasn't telling her about myself, and that I couldn't tell her what it was. I told her that if we were going to go to bed together she would have to be willing to accept the untold thing and the physical constraints it required. She took this well. She was curious. Not frightened. She didn't need to know, she said.

The conversation moved on to something else and then back again to the prospect of sex and my visible discomfort with skirting the edge of full disclosure. We decided to go into the bedroom. Once there, she lit several candles by the bed. I sat on the edge of the bed, which was low to the ground, and asked her to sit with her back to me on the floor. She did so, leaning against the mattress between my legs. I gathered her long hair in my hands and draped it over one shoulder, exposing one side of her neck. I eased down the V-neck of her sweater, exposing the shoulder, and traced her skin with my fingertips, behind the ear, along the hairline, the collarbone. I leaned down to kiss the places I'd touched. She moved in response, lolling her head to the side. She reached up behind her and placed her palm on my cheek. She would feel the stubble now for sure and know that it didn't feel like stubble should. The jig was probably up. Anyway, this was about as far as I was willing to take it - the make-up was smeared now for sure - so I got up from the bed to move around in front of her, to face her on the floor.

"Do you want me to show you or tell you?" I said. "Whichever you prefer." It took me longer than I'd thought it would to spit it out. I was holding her hands when I finally did. "I'm a woman." She didn't pull her hands away. I went on immediately to fill the space. I told her about my plan to write a book and why I was doing it. Then I waited. She was still quiet. Then she said, "You're going to have to give me a few minutes to get used to this." We sat in silence. Clearly, whatever physical deformity she'd been expecting, it hadn't been femaleness.

She took up one of my hands, which she was still holding, and examined it. "These aren't a man's wrists," she said, caressing them, "or a man's hands, or a man's skin." She looked me over for a few minutes in the dim light, making out the feminine parts and nodding. "I always thought you weren't very hairy for a man," she said. She laughed a little and said, "Well, now I can tell you that my nickname for you in the past few weeks has been My Gay Boyfriend. You set off my gaydar the first time I saw you. Your hair was too groomed and your shirt too pressed, and your shoes too nice."

Sasha and I went to bed together, and obviously Sasha had to thereby revise her hard ideas about lesbianism and her desire to "go there". Yet she did so with stunning alacrity for someone who, I'm fairly certain, was not a closeted lesbian all along, or even a genuine bisexual. In our weird stilted exchanges, we had connected mentally in some way. Maybe I'd come to admire the adventurer and even the oddball in her. Maybe she just desperately needed a good friend. There could be a thousand reasons, good or bad, but I think none of them had much of anything to do with sex. And this, I'll maintain in an entirely unscientific manner, is a stubbornly female tendency.

The trendy term "metrosexual" came up a lot in my company during my dating career as Ned. Ned wasn't everybody's type by a long shot. Sure, some women - like Sasha, as it turned out - still wanted to go to bed with him once they knew he wasn't a guy. But plenty of others didn't.

If you have never been sexually attracted to women, you will never quite understand the monumental power of female sexuality, except by proxy or in theory, nor will you quite know the immense advantage it gives us over men. Dating women as a man was a lesson in female power, and it made me, of all things, into a momentary misogynist, which I suppose was the best indicator that my experiment had worked. I saw my own sex from the other side, and I disliked women irrationally for a while because of it. I disliked their superiority, their accusatory smiles, their entitlement to choose or dash me with a fingertip, an execution so lazy, so effortless, it made the defeats and even the successes unbearably humiliating. Typical male power feels by comparison like a blunt instrument, its salvos and field strategies laughably remedial next to the damage a woman can do with a single cutting word: no.

Sex is most powerful in the mind, and to men, in the mind, women have a lot of power, not only to arouse, but to give worth, self-worth, meaning, initiation, sustenance, everything. Seeing this more clearly through my experience, I began to wonder whether the most extreme men resort to violence with women because they think that's all they have, their one pathetic advantage over all she seems to hold above them. I make no excuses for this. There are none. But as a man I felt vaguely attuned to this mind-set or its possibility. I did not inhabit it, but I thought I saw how rejection might get twisted beyond recognition in the mind of a discarded male where misogyny and ultimately rape may be a vicious attempt to take what cannot be taken because it has not been bestowed.

There were other surprising discoveries. With all the anger I felt flowing in my direction - anger directed at the abstraction called men - I was not expecting to find, nestled within the confines of female heterosexuality, a deep love and genuine attraction for real men. Not for women in men's bodies, as the prejudicial me had thought. Not even just for the metrosexual, though he has his audience, but for brawny, hairy, smelly, stalwart, manly men; bald men, men with bellies, men who can fix things and, yes, men who like sports and pound away in the bedroom. Men whom women loved for being men with all the qualities that testosterone and the patriarchy had given them, and whom I have come to appreciate for those very same qualities, however infuriating I still find them at times.

Dating women was the hardest thing I had to do as Ned, even when the women liked me and I liked them. I have never felt more vulnerable to total strangers, never more socially defenceless than in my clanking suit of borrowed armour. But then, I guess maybe that's one of the secrets of manhood that no man tells if he can help it. Every man's armour is borrowed and 10 sizes too big, and beneath it he's naked and insecure and hoping you won't see.

That, maybe, was the last twist of my adventure. I passed in a man's world not because my mask was so real, but because the world of men was a masked ball. Eventually I realised that my disguise was the one thing I had in common with every guy in the room. It was hard being a guy.

Rather than choosing to become a woman again, it is probably truer to say that I reverted to form. I stopped faking it. I came back to myself, proud, free and glad in every way to be a woman.

· This is an edited extract from Self-Made Man: My Year Disguised As A Man, by Norah Vincent, published next month by Atlantic Books at £9.99. To order a copy with free UK p&p, call 0870 836 0875 (theguardian.com/bookshop).