The threat of prison should be the ultimate deterrent to bad behaviour. The stripping away of individual freedoms and the destruction of family and community bonds should make even the most wayward child think twice.
Unfortunately, sometimes it does not work like that. In the minds of some children, prison has been mythologised through fiction, the media or the boasts of friends who "know someone who has been there" into something that is cool, easy to handle or necessary for a sought-after reputation.
It is seen as the job of the teacher to wade through this misrepresentation and open students' eyes to the reality - not just because it is an important part of education to appreciate the consequences of breaking the law but also because doing the right thing is the foundation of behaviour both inside and outside the classroom. But do students believe teachers when they talk about prison? After all, what does a teacher know of life behind bars?
It is a point worth debating. In drugs education, it is increasingly likely, in the UK at least, for lessons on the dangers of drugs to be delivered by ex-addicts and charities working with addicts rather than by teachers. Similarly, members of the emergency services now frequently go into schools to talk about their professions. The theory is that the message has more impact coming from someone with real-world experience. So should prison officers and serving convicts be going into schools? Philip Garner, professor of education at the University of Northampton and project director of the Behaviour2Learn programme, thinks so.
"It is really difficult to say how big an impact the drugs and emergency services initiatives have in concrete terms, but if you look at the feedback from students, you can see the message hits home," he explains. "Looking at things from a theoretical perspective is very different from a real-world experience - the latter brings it to life for young people."
Paul Wilkinson is the founder and chief executive of Prison! Me! No Way! (PMNW), a charity that brings home the realities of incarceration to schoolchildren of all ages across the UK. Unsurprisingly, he agrees with Garner.
"Teachers do a fantastic job - we are not trying to replace them," Wilkinson says. "We see ourselves as partners to them, as we have something different to give. What we deliver is real-world insights for the children, both from prisoners and from prison officers."
PMNW connects with around 100,000 children a year. Wilkinson, a former prison officer, founded the charity in 1993 and since then it has built up a number of programmes for schools. The most popular is a Crime and Safety Awareness Day for whole-year groups aged 12-14, which consists of a series of workshops run by volunteer prison officers. Activities include recreating experiences of prison life - such as being marched monotonously around a parade square or being pushed into a cell that has been recreated in the back of a prison van - plus talks from prison officers and serving convicts, and role play.
"You have to be very careful not to glamorise the prison experience," Wilkinson says. "So we have serving inmates who talk not about their crimes but about the deprivation and loneliness of prison life, how when the doors close the bravado disappears and tears are shed."
He explains that the strategy is not to scare students with tales that will shock them into submission but simply to inform them of the consequences and reality of prison.
"We do not dictate, we are not about saying 'this is right' or 'this is wrong'. We are there to inform the children that certain types of behaviour result in certain consequences, so that they can make informed decisions about that behaviour," he says.
A teacher could, of course, relay the same messages, but Wilkinson says it would not have the same impact. He explains that it is crucial that the information comes directly from those with real-world experience - it carries more weight and has more credibility.
However, teachers do have a role to play alongside PMNW. The charity provides resources such as DVDs and activities that can be incorporated into lessons after its workshops, in order to build on the lessons learned. It is vital, PMNW says, that the real-world input runs in conjunction with these resources.
And support for PMNW comes from multiple sources. The UK government's Charities Evaluation Services found that PMNW had "lasting effects" on students and describes the Crime and Safety Awareness Days as a "very good... learning event".
Feedback from schools and students who have experienced the awareness days is also positive. One teacher from a school in Lincolnshire, England, states: "I believe this will have a greater effect than teachers could ever have on whether a young person decides to go along with the crowd or take a stand and make the right decision."
Meanwhile, a Year 9 (aged 13-14) student from a Cambridgeshire school, says: "Talking to individuals who have actually been in prison really helped (me) to understand how committing crimes affects you and your future."
These comments are typical and Wilkinson says he has seen long-term beneficial effects on behaviour both inside and outside the classroom. "We visited the same school three years in a row. The first year we were spat at, pushed and abused. Teachers were being assaulted. By the third visit, many of these challenges and this behaviour had lessened markedly."
He agrees with Garner that it is difficult to quantify the direct impact of schemes such as this, beyond anecdotal or circumstantial evidence. However, he is convinced that PMNW and other schemes like it (some prisons run their own projects in the UK, US and Australia) do have a beneficial effect.
Others are more dubious. Aleks Kajstura from US organisation Prison Policy Initiative says that similar schemes in the US have proved ineffective. TES behaviour expert Tom Bennett, meanwhile, questions the impact on general classroom behaviour. However, he believes that charities such as PMNW still make a valuable contribution to teaching.
"[Offering] this type of perspective and (showing) the real consequences can be powerful," he says. "One of the most useful things we can do for children is to give them access to experience they could not access otherwise - this does that."
How much of an impact a direct, real-world prison experience has on student behaviour is, then, a matter of debate. But Wilkinson has an interesting statistic he likes to disclose to doubters: in Jersey, where all students aged 8 to 18 have been through the PMNW programme, the numbers of youth offenders in prison and youth court appearances have dropped markedly since the charity began its work on the Channel Island in 2002.
He is not saying the charity is directly responsible, but as with behaviour in general, he and others certainly think a real-life glimpse of prison has a substantial contributory impact.
The consequences of going to prison are generally not fully understood by students.
Some claim that a real-world insight into prison, given by inmates and people who work in prisons, can have a greater impact in communicating the consequences of a prison sentence than talks by teachers.
This real-world insight is said to improve student behaviour inside and outside the classroom.
Charities such as Prison! Me! No Way! lead workshops at schools that give students an insight into prison life.
For more on Prison! Me! No Way! visit www.pmnw.co.uk
For the Charities Evaluation Services report on PMNW, visit bit.lyPMNWreport
Discover how having a parent in prison affects students' behaviour. bit.lyParentInPrison
Read about students' experiences of a prison visit. bit.lyStudentPrisonVisit.