Comedy gigs in Scottish prisons are nothing new, but recently prisoners in HMP Barlinnie took to the stage and delivered a short routine to over 100 fellow cons.

While it won't stop reoffending overnight, staff believe the project plays an important part in the prison's rehabilitation efforts. This remains an important issue with Government figures suggesting that of all those released from prison, over half are reconvicted within a year.

Inmates involved include Benjamin, who grew up in Priesthill, in the south of Glasgow. Addiction and violence featured prominently in his childhood, he says. Laughter less so.

"Out of all the boys I grew up with, nine out of 10 of us ended up in prison. Some of them are even dead, through drugs," he says.

No stranger to Barlinnie, he spent his first night there at 18 while on his way to HM Young Offenders Institution Polmont.

He has since returned on several short-term sentences but at 37 is determined his current two-year stint will be his last.

"This is the longest sentence I've done. Before it was three months, six months - every time I got out nothing much had changed. But this time I've lost my flat, my girlfriend, I've no clothes, nothing out there. I'll be starting from scratch."

With a longer sentence he hopes he can now change direction. It is hard to break from old habits such as drinking, he adds, but he wants to be a better example to his 15-year-old son. "I've spent so long in here I've already cut away from everybody, so it's not as if I've got anything to lose."

Benjamin says jail humour is sometimes essential to surviving prison. "It's a good way to defuse a situation. I've seen boys arguing and one will just cut a guy down and he won't know what to do while everyone's rolling about the floor, laughing. Some people think you need this tough guy bravado. But you don't – just have a laugh and be yourself."

For staff at the prison, the hope is a dose of comedy could help improve inmates' mental health and even reduce their chances of reoffending.

In October, prison staff drafted in familiar faces on the Scottish comedy circuit, Susan Morrison, Keir McAllister, John Scott and Bruce Morton, to perform for a captive audience as part of their Laugh? I Nearly Died tour of Scotland's Highlands and Islands, which aims to challenge misconceptions of depression and suicide within isolated communities.

This was followed by a series of comedy workshops, specifically aimed at prisoners whose mental health has caused concern.

"The comedy class is brilliant," says Benjamin. "It has given me a bit of confidence. Did I think I'd be up on stage telling jokes to a hundred bodies? No way. Hopefully I'll do something like this again when I get out.

"I'm too stupid to work, too lazy to be a thief, so a comedian would be OK, wouldn't it?"

Jokes told by the inmates tended towards the blue end of the spectrum, with celebrities and lawyers among the targets. Phillip Woodlock, head of offender outcomes, helped supervise the show which brought an end to eight weeks of workshops. "I think it went very well," he said. "Of the 10 guys, four went on stage, four did scriptwriting and the other two helped with setting up the stage and understanding how a comedy night comes together, so all 10 have been involved. I'm sure we'll do something similar [again].

"Their self-esteem has definitely been raised – it's how you transfer that back out into the community. They are confident within here now but I would think it's easier to take the learning they've got now out there than not having any learning."

Some might baulk at the very idea of offering comedy nights to convicted prisoners, but Derek McGill, governor of HMP Barlinnie, describes the project as a success story.

He explains: "It serves two purposes: one is to get the prisoners on stage, learning skills, building their confidence and making them think for themselves; and the other is to get people to understand they can actually sit in a room with someone they don't like.

"There are guys sitting here who hate the guys who are sitting there and would normally just fly into them. But no, they sit and behave and we don't get any bother."

Susan Morrison, who led the comedy workshops, said many prisoners had a "resistance to individual thought".

She says: "There's a huge hive mentality in a prison, as you would imagine, but they also tend to come from hive mentalities in their families, groups of friends.

"It is getting them to be individuals that's the drawback. Comedy helps. If you can make someone laugh then you're halfway there, aren't you?"

Jason, 41, from East Kilbride, was the first Barlinnie inmate to take to the stage. Serving a life sentence for murder, he has spent 20 years – nearly half his life – behind bars.

Nearing the end of his sentence, he is in the "top end" of the prison with increased freedom. He is waiting to get statutory leave (home leave) to see his parents and will then progress to a six-month work placement. "After I've done that, I'm away."

He admits he hasn't done himself any favours with his behaviour when he was out awaiting is appeal, which resulted in a further sentence. But he claims institutionalisation hasn't helped. The comedy classes have, though. Speaking before his set, three minutes on stage was about to feel like the longest three minutes of his life.

He says. "I have the ability to make people laugh. I've got a good sense of humour, I just come out with it. But because now I need to get up in front of everybody, I've got to rehearse what I'm saying.

"Comedy is definitely a good thing to have in prisons - as a coping mechanism. They say laughter is the best medicine, don't they? So we'll see what happens."