Late at night in so many suburban homes there are men like this one, hunched over flickering computer screens looking at pornography. Often their partners aren't aware of what they are doing, assuming the poor dears are simply working late or catching up on a missed sports podcast. Most men keep these viewing habits to themselves - secret men's business - fearing discovery would mean a solid stint in the doghouse.

Everywhere men look there's another woman banging on about the dangers of porn. British sociologist Gail Dines was recently holding forth on the ABC's Q&A about the damage done by ''body-punishing, brutal, dehumanising and debasing'' pornography.

Then came one of the viewer's video questions, featuring Jeff Poole, a cheerful man with a greying goatee. ''Miss Dines, I am one of the third of the Australian population who cheerfully consumes pornography,'' he said, explaining he had been watching porn for more than 30 years. ''In all those many thousands of hours of wobbling pink bits, I've never seen any of the things you talk about. I've never seen the degradation of women or men for that matter. I've never seen rape, real or simulated. I have never seen violence.'' Porn, he added, had never harmed his relationships.

He spoke for a huge audience of men who hear constant negative discussion of pornography and wonder why their own experiences are so very different. ''What's the problem?'' they say, bewildered at women's outrage at what they see as a harmless outlet for the strong male sex drive.

To many men, porn seems a perfectly normal aspect of male sexuality that provides comfort and entertainment, and redresses the serious sexual imbalance between male and female desire. (The problem of lost libido in women is well documented - Doing it Down Under, published in 2005, cited the results of a university survey of about 20,000 people that found 55 per cent of women reported low sexual desire, twice the number of men.)

For all the scaremongering about misogynist, hate-filled porn, the attraction for most men is the antithesis of violence against women. What most men really like watching is sex involving eager, willing women.

Men are often defensive about their use of porn, not understanding what the fuss is all about. ''Yes, I have always been interested in pictures of women and of people copulating or whatever. I feel somewhat embarrassed at the thought of being caught watching, by wife or daughter but, what the heck, I am a grown man of 59. I suppose my wife knows I occasionally watch internet porn (but maybe not how much). I don't think she approves but since we don't have sexual contact I suppose she ignores it.''

This is from a man who took part in my recent project on male sexuality (published last year in my book, What Men Want), involving 150 men writing about their sexual joys and frustrations, including how they cope with their strong drives.

Like many, this man had spent years with no sex in his marriage. Pornography provided such men with an outlet that helped keep a lid on their frustrations - sometimes with a partner's reluctant consent.

One 37-year-old reported his wife had asked him early in their marriage if he'd be willing to give up watching porn. ''I responded by saying yes and then asked her whether she would have sex whenever I felt like it, given that I would not have any pornography. She said no, so to this day I still have my porn. These days my wife accepts it and I think she actually prefers I watch pornography instead of hassling her for sex.''

Separate interviews I conducted with young men aged 23 to 35 show many men seek out porn rather than pressure a partner for sex. Dale*, 25, has a great sex life with his partner of two years but there are times mid-week when he knows she's too stressed for sex. ''I don't want to bother her if I know she doesn't want it. Watching porn and wanking means it's done and dusted in five minutes. It's quick and easy and relaxes me - no big deal.''

Yet it was a pretty big deal when she caught him doing just that some time ago. Her hissy fit wasn't just about the porn but the masturbation - she's happy to share a porn movie with him occasionally and it turns them both on. But it took some persuading for her to accept that the occasional hand job didn't mean he wasn't happy with their love life. Watching porn for most men is accompanied by masturbation - and that's something many women still find hard to accept. Many women react to the masturbation as a separate issue from porn because they worry they aren't satisfying a man if he masturbates.

The intrigue of pornography for men is also driven by their intense curiosity about sex and their powerful, visual sexual imagination. There's always been fuel for this - one man reported spending his adolescence poring over shopping catalogues: ''The best ones were when Kmart or Target had a sale on underwear - all these young women in sexy underwear. It was irresistible.''

While the older men in my project wrote about poring over dad's stolen Playboys, today's young men grow up with an internet sexual smorgasbord. Most report roaming far and wide, from vanilla sex to the ''oh my God'' offerings. One mentions breakfast conversations at his university college, dominated by boys sharing notes on the latest online ''girl shagged by donkey'' type video. Throughout history there has been sexual material designed to stir male loins, from Roman frescoes and Japanese screen prints to Victorian ''dirty postcards''.

Yet other motivations also push men away from real-life sex towards the comforts of porn. These complexities were vividly revealed by a couple who wrote diaries for my research. To begin with, Zoe, 38, was fine about her husband Leo, 44, using porn to masturbate: ''I'm well aware men like to relax with porn. It's a real boys' club.''

But normal sex presented problems for Leo because his wife was more sexually experienced than he was, contributing to his anxiety about losing erections. Plus he wasn't keen on the sex Zoe really enjoyed. ''He doesn't like a lot of foreplay or kissing. He thinks it's all girly crap.'' This was also a second marriage for them both, complicated by major struggles over stepchildren - the couple wrote more in their diaries about the hassles of a blended family than they did about sex.

As the tensions in their relationship increased, Leo retreated more into the world of porn.

''Watching porn gets me aroused which leads to masturbation. This helps me relax and sleep and it is a lot less effort than actual sex. With Zoe, some of my anxiety kicks in about losing my erection so in some ways porn is almost better than actual sex as I can watch it for one to two hours and there is an endless supply of beautiful women, all doing stuff most of us guys can only dream of.''

Zoe is a volatile woman whose reaction to conflict was often explosive. Leo's response was to retreat, turning more to porn. Tensions then spilt over into their sexual relationship. ''He would like me to behave like a porn actress,'' Zoe complained. Within eight months the couple had split up, leaving Zoe convinced porn had poisoned their marriage. Yet the situation was complicated by Leo's sexual anxiety and his immature sexual attitudes.

That's the problem with the common argument that porn turns men off real-life sex. The reality is sex can be threatening for men, particularly if they have fears about performance or partners who are hard to please.

''Pornography can be a thick emotional buffer zone, separating a man from rejection, masking his insecurities and perceived inadequacies,'' write sexologists Bob and Susan Yager-Berkowitz in their 2007 book, He's Just Not Up For It Anymore. Most men are sensible enough to avoid retreating into a sexual fantasy world. I've talked to men who cut back on their porn viewing when they felt it was distorting their feelings about normal sex. ''One time I was using it a lot and I found sex with my partner wasn't as exciting as it usually was. After that I was careful how I use it. I don't want that to happen,'' says Joe, a 26-year-old arts student. But lonely men, socially inadequate men, are more vulnerable to the seductive comfort of porn.

Of course there are men whose upbringing and social experience draws them towards misogynist, violent pornography. Many of the young men I spoke to were aware of men caught up in this world. One talked of mates he went to school with who had always had ''strange attitudes to women, seeing them as sex objects''.

Their attraction to particular porn fantasies - ''like 50 guys with one woman'' - simply reflected the way they had always seen women. Most men aren't interested in this violent material. ''I don't like the mean stuff … that's just not my personality,'' commented one young man, mentioning that he worries whether women in porn films are being coerced into participating.

The suggestion that porn changes men's attitudes to sex is really questionable. While there's a body of psychology research suggesting exposure to porn has that effect, Professor Catherine Lumby and colleagues in The Porn Report, published in 2008, found this laboratory-based research to be contradictory and unlikely to reflect real-life situations. ''The entire tradition of social science research into pornography has started with the assumption that porn is a major cause of negative attitudes towards women and has set out to prove this,'' conclude these Australian academics.

These researchers found mainstream porn to be largely free of violence and other degrading material. Instead, the huge growth area online is the DIY amateur porn industry, where ordinary men and women are baring all, grunting and groaning in front of web cameras - a far cry from the dark and dangerous world so many warn about.

Many men will admit porn has opened their eyes to new sexual practices. Many use porn to enjoy fantasies they can't get at home. Alex, 65, has always had an interest in anal sex, which his wife won't consider.

And that's where porn comes in - seeing women apparently enjoying this taboo activity is very much part of his pleasure. His wife allows him to rub his penis between her butt cheeks. ''I find having sex in her bum crack such a turn on. My brain knows one thing but my dick does not have a brain so thinks it is right into her anus,'' he cheekily explains.

Anal sex is high on the list of porn fantasies that rarely get played out in real life - although in some couples both partners enjoy it. Porn has also helped to change attitudes to oral sex, shifting it from an experience that 30 years ago most men only dreamt about, to an hors d'oeuvre that for many teens is on offer long before the main course. This shift in oral sex patterns is often mentioned as an example of the negative effects of porn - since it is usually males on the receiving end. Yet there's ample evidence that porn has also taught men that cunnilingus is a great route to women's pleasure. Many men are keen to try it but research by sex therapist Gabrielle Morrissey showed young women's self-consciousness about their bodies often prevents this from happening.

Porn is giving men new ideas about sex and that can cause tension in relationships. Many young men report trouble over the ''money shot'' - that peculiar in-her-face finale common in pornography. Unsurprisingly, many women aren't keen on ''facials'' (having a man ejaculate in her face). James, a 35-year-old engineer, found himself backpedalling fast with a very upset young lady reacting badly to this suggestion. ''I realised it wasn't appropriate or respectful,'' he reports and has never tried it since. But other men find women happy to explore this rather strange practice.

So yes, internet porn is encouraging some men to suggest exotic practices - and some women take offence at that. But others are happy to participate and to watch porn, with or without their partners. The problem comes when men try to bully women into things they don't want to do - but arguably porn has nothing to do with the insensitivity causing men to behave in that way, which stems from their cultural and social backgrounds.

For all the sky-is-falling warnings about pornography, the reality is far less frightening. Pornography brings out the worst in some vulnerable men and that's cause for concern. But the real struggle is for women to come to terms with what pornography reveals about men and their relentless, lusty drive. That's what many women just don't want to know.

* False names have been used for people quoted talking about their pornography use.

Bettina Arndt is a former clinical psychologist and sex therapist and author of What Men Want - In Bed.