If research is right, 20% of men are capable of feeling sexual arousal to children below the legal age of consent. That is an eye-opening statistic. One in five men: in this country, that's around six million men.

This claim is backed up by eight different studies conducted between 1970 and 2006 in Europe and North America, using questionnaires and a “strain gauge” to measure “physical response”, for example to pictures or audiotaped sexual stories. The research found a significant proportion of the men in their studies – ranging between 17 and 58% – showed sexual arousal to children under the age of twelve. It is important to point out that these studies were all relatively small samples and I don't know how robustly they were designed and conducted, but they still suggest there is an important truth here that we need to learn much more about. The most important points, for me, are firstly that it seems pretty clear that most men with a sexual attraction to children, including those who go on to sexually abuse children, are not in prison but out in the community. And, secondly, that you probably know some of them.

So what is the impact? Again, here are some more eye-opening statistics. The NSPCC tells us that one in twenty children has experienced contact sexual abuse. That's a conservative figure. Recent research by the University of Bedfordshire has found that between 87% and 95% of children who are sexually abused do not report it to an adult at the time. Very slowly, as they grow up, they may tell, perhaps decades later, perhaps never. So it's very hard to know exactly how many people have been abused. The Lantern Project recently estimated that over 11 million people are survivors of child sexual abuse in Britain today (out of a total population of 64 million). That's a lot of people living with the after-effects of these experiences.

An overview of research in 2000 found that a likely figure is that one in six of our children will experience sexual abuse. That's somewhere in the region of one in four of our girls, one in eight of our boys. This is serious, and I hope you really get exactly how serious. If we accept the finding (broadly accepted by the Government, child protection charities, and the World Health Organisation) that “one in six children are sexually abused”, it lends weight to the statistic at the beginning of this article, that one in five men are capable of finding children sexually attractive. We thought it was only “evil paedos”, those “sick monsters” over there, who found our kids sexually arousing. No, it's one in five of all men, it seems. That may stop us in our tracks but it does help to make sense of the epidemic levels of child sexual abuse we are having to come to terms with. For that many children to be abused, quite a lot of adults (and the figures suggest primarily men) would have to be abusers.

Does that mean one in five men are potential paedophiles? Well, in order to sexually abuse a child (including looking at online photographs or videos or webcams of sexual abuse) it's common-sense that you'd personally need to find that sexually arousing on some level, or you wouldn't be motivated to do it. Curiosity might start you off, but sexual arousal makes you continue. It's estimated that there are now around 100 million child sexual abuse images online (up from 7,000 in 1990) and at least 50,000 offenders in Britain known to be viewing them. In 2000, Detective Chief Inspector Bob McLachlan, then the head of Scotland Yard’s paedophile unit, used Home Office statistics to suggest that there may be as many as 250,000 sex offenders living among us, including those not convicted.

Sexual abuse is quite clearly about (the misuse of) power, but it is also about sex. Otherwise it seems to me you'd just hit or yell or sneer at the poor child, instead of choosing to involve that child in your sexual gratification. If the research is correct (and it’s important to keep emphasising this, as we really need more research here), roughly four out of five men would have no motivation, under any circumstances, to involve a child in their sexual behaviour. The other 20% of men (look around you, think about all the men you know) are tempted to do so. Does that make them all paedophiles? Again, the research suggests that only a much smaller percentage, approximately one in every hundred men (maybe as many as one in every fifty), are likely to meet the threshold for a clinical diagnosis of paedophilia.

Defining paedophilia is a bit more complicated than you'd think. Recently there have been five different attempts at developing diagnostic criteria everyone can agree with, and none are yet fully satisfactory. Briefly, to be defined as a paedophile, you need to be aged at least sixteen yourself, and five years older than the children you are attracted to; you need to have had recurrent fantasies, urges or sexual activities involving children, occurring over a period of at least six months; and either you have acted on your desires or your desires have caused you distress or difficulty. If all those are true, you are a paedophile, regardless of whether or not you are also sexually attracted to adults. If your entire sexual life revolves around constant fantasies or urges involving little children but you do not act on them and they do not distress you or cause you difficulties, then you wouldn't be classed as a paedophile. Confusing, isn't it?

Initially baffling though it may be, sexual interest in children doesn't necessarily mean you are a paedophile, and sexual interest in children doesn't necessarily lead to offending behaviour.

So, going back to the one in every five of the men in your life, what does their sexual interest in children actually mean? For most of them, most of the time, not much, as far as we know (funding organisations, please note: we need a LOT more research here, please). Drawing on the answers from my (admittedly very small) sample of 50 respondents in the Minor-Attracted Adults (MAA) Daily Lives Project I conducted online, and from the kinds of topics raised on paedophile web-forums (go and have a look for yourself if you're interested), the sexual desires that this 20% of men might feel are likely to run the gamut from a mild, infrequent experience of little consequence, simply a feeling that arises and passes, or something that defines one's whole life. A few respondents explained that they were heterosexual but found themselves sexually attracted to boys, sometimes to their own surprise and confusion. Few things seem straightforward in the realm of sexuality.

Sexual attraction to children can include a spectrum of desire and action which – depending on circumstances, opportunities, predispositions and moral stance – may encompass romantic, never-acted-on, daydreams of dancing with a certain child, for example, holding her in your arms, or hugging a particular boy, giving him a back-rub, right up to – as we all know only too horrifically – violent, sadistic rape, torture and murder. That's the spectrum of desire and action encompassed in men's sexual response to children.

One paedophile told me: “I imagine including little girls in my daily activities. I could be driving to the store, and I will imagine that a little girl was going with me, and imagine what we would talk about on the ride there.” Another said: “I think beautiful Little Girls are just amazing, and I want to gain a sense of what it must feel like to be the Girl, and to be the Girl in the situation of being adored, being loved, being made love to.” A third said: “If I see a handsome boy I sometimes fantasise about how he would look naked. It makes me horny.” Others told me more disturbing fantasies of oral sex or penetration.

While some of the respondents had previously sexually abused children, others among the respondents I communicated with were clear that these fantasies would never be acted on and they were used as an outlet to prevent actual sexual contact. Typical was ‘Louis', who wrote that originally his fantasies “would involve me being a super-hero and rescuing the boy from some evil bad-guy – now I'm happier just imagining a friendship. These fantasies I would have several times a day, every day … The second kind of fantasy involves sexing up a boy accompanied with masturbation. … If I don't have regular sexual release I find myself tempted to fantasise about real boys, to be more sexually interested in real boys, to follow boys around in shopping centres ...”

We cannot know what is happening in people's heads, how much sexual fantasy towards children exists, how much is controlled, how much is translated out of fantasy into actual, dangerous, behaviour. But what we do know is that we must stop being so squeamish – there is a lot we need to learn more about.

The scale of child sexual abuse in Britain is currently at epidemic levels. Around one in every five men (around six million men) is capable of finding children sexually arousing, and around one in every hundred men (approximately 300,000 men) has an exclusive or primary sexual attraction to children. Meanwhile, prisons are full, the NHS is on the point of collapse, and we as a nation are in debt up to our eyeballs. But this is an article about morality – about how we choose to act in the world as moral agents – and, because of that, it is fundamentally about hope and optimism. The only way out of this fiasco, this wholesale betrayal of our children's wellbeing, is through all of us taking some active responsibility.

There are good and effective strategies already existing which can fundamentally alter child protection in this country.  If we intervene before children are harmed, then we don't have to deal with the long-term consequences of our traumatised children. These initiatives don't cost much money; they actually save money and they will keep our children safe. We need to get motivated and influential people behind these strategies to get them into the mainstream, now.

At present, there are around 11,000 sex offenders in prison, of whom less than 1,000 are likely to get any sex offender treatment. That has to change. We do already have a telephone helpline, run by Stop It Now!, which people can phone if they are worried about their own or someone else's sexual behaviour towards children. The number is 0808 1000 900 but it doesn't operate at weekends and last year it missed four times as many calls as it answered, with over 2,000 people a month being unable to reach an advisor. That has to change. In Germany and the Netherlands there are now imaginative and highly effective advertising campaigns addressed to all those paedophiles living out in the community, unknown to any authorities, asking them to come forward voluntarily and get help with managing their sexual urges. It has been so successful that, from one initial pilot project (funded by Volkswagen), there are now ten centres around Germany offering treatment and support for those living in the “dunkelfeld”, the “dark field” outside the purview of criminal justice or healthcare. We urgently need initiatives like Project Prevention Dunkelfeld to be set up in Britain.

To keep children safe, we have to tell the hysterical tabloids to shut up and get real. All adults must take responsibility and be held accountable for their actions – yes, that means you too, newspaper editors. Child protection has to be about prevention first and foremost.

Child sexual abuse can be prevented when we adopt a public health approach. “Clunk click, every trip” now makes us wince but the seatbelt campaign worked. So have the drink-driving and anti-smoking campaigns. Now we need a child protection campaign which is equally effective. In Texas, in the land of the free and the home of the electric chair, they have recently been able to close down three prisons simply by adopting a robust community justice approach. Those three prisons are no longer needed. The Right on Crime approach uses a form of restorative justice which has a proven impact on people's behaviour by challenging them and holding them accountable. How about an approach like that with the 10,000 sex offenders who right now are sitting in prison and then being released back out into the community with no treatment?

On Newsnight recently, a senior police officer misunderstood my work and challenged me with “You wouldn't want a paedophile babysitting your children!” The answer, realistically, is that, more often than we realise, they are already babysitting our children. We need to face up to that and we need to respond effectively.

Dr. Goode's book, Paedophiles in Society: Reflecting on Sexuality, Abuse and Hope, is available here.

Image credit: lucyburrluck