It would be easy to snicker at reports of Russell Brand’s treatment in prison. Following his conviction for rape and three counts of sexual assault, the former comedian has been sentenced to 10 and a half years behind bars. At HMP Wandsworth, where he spent the weekend awaiting sentence, prisoners have reportedly been chanting: “There’s a Brand new nonce on the wing! A Brand new nonce on the wing!” Other reports have raised the possibility of violence against him.

Given the nature of his crimes, many will feel little sympathy for what fate may be awaiting Brand. In fact, many will regard it as thoroughly deserved. But if my 16 years in prison taught me anything, it is that one of the greatest barriers to rehabilitation is often other prisoners themselves. So-called prison justice is rarely justice at all.

Consider who is actually enforcing this “justice” system. The informal prison hierarchy places sexual offenders, particularly those convicted of offenses against women and children, near the bottom. But those enforcing this hierarchy are not necessarily motivated by moral concern for victims. Many are themselves violent individuals who relish bullying and exerting power over others. Put a six-foot-seven hardman with a crooked nose in Brand’s place, and many of those same voices would quickly fall silent.

Take the recent killing of Ian Huntley, the notorious Soham murderer. Many celebrated his death as a form of prison justice, overlooking the fact that Anthony Russell, who was charged with his murder, is himself serving a whole-life sentence for killing three people, including a pregnant woman he also raped. Where is the morality in one convicted rapist and murderer allegedly killing another?

I saw the effects of this culture throughout my sentence. Prisoners who are constantly intimidated won’t spend much time reflecting on their crimes. They’re too busy worrying about what might happen to them next, with some hiding in their cells and others turning to drugs or self-harm. Some even look for protection by joining gangs, including extremist groups, only to end up being used or dragged into more violence.

Some will argue that making prison frightening serves as a deterrent. Yes, there may be prisoners so intimidated by their experience that they never wish to return. But not wanting to return to prison and not returning are two very different things. Fearing prison doesn’t necessarily change the way someone thinks, or stop them committing another crime.

Prisons offer treatment, therapy and programs designed to tackle offending behavior, including for sexual offenders. But for any of this to work, prisoners have to be honest about what they’ve done and why. That’s difficult enough without having to watch your back in the shower, in the dinner queue or every time your cell door opens.

There is a wider problem, too. When prisoners are left to intimidate and punish one another, staff lose their authority. The most violent inmates gain influence, while everyone else is left to fend for themselves. Some end up on the fringes of prison life, with little chance of getting out. This only entrenches the criminal culture that prisons are supposed to break down.

Reports suggest Brand has been moved to a wing for vulnerable prisoners. I suspect the governor will be under pressure to keep him safe. But keeping Brand safe is just one part of a much bigger job. A far more important question is whether he emerges from prison a changed man.

The last thing society should be encouraging is bad people to continue doing bad things, simply because we dislike the person on the receiving end.