Who are the most untrustworthy and dishonest people in society? Estate agents? Tabloid hacks? The people who compiled the train schedule for Southern Rail?

What about prisoners? Surely, it would be crazy to trust them.

But that is precisely what Alison Liebling suggests we should do. And she should know. She’s been in and out of prison for three decades now. Not as a serial recidivist, but as a Cambridge University criminologist. Her current title is Professor of Criminology and Director of the Prisons Research Centre.

Her epiphany about the importance of trust came in Whitemoor prison in Cambridge. She had researched this prison in the late 1990s. A decade on, the Ministry of Justice asked her to return — following a serious collapse in relations between staff and prisoners. Liebling described how the prison had become “paralysed by distrust”. Rereading her original report she noted something she had missed at the time — how often she had described the guarded forms of trust that had previously existed.

Trust became an ultimate litmus test for assessing jails.

There are various more concrete ways to measure how well a prison is functioning — the suicide rate, for example, or the level of violence or drug abuse. These tend to be lower, she says, when prisoners are treated with respect, and when officers have the time, and take the time, to treat prisoners as individuals. All of us — even prisoners — want to believe we can be trusted. Treating people as if they can never be trusted — as though they are an ever-present danger and habitually dishonest — is felt by prisoners as dehumanising and disrespectful. Such an approach, Liebling’s research suggests, fosters an atmosphere of bitterness, fear, and hostility.

Of course, Liebling is not advocating naïve trust. Borrowing a phrase from the philosopher Onora O’Neill she talks of ‘intelligent trust’, knowing when prisoners can be let out of their cell, whether they can be relied upon to perform a task, whether they can be trusted to open a parcel with a pair of scissors. And trust flows in both directions. Prisoners want to be sure that the letter they hand to the officer will actually be posted. Liebling has devised a questionnaire to measure levels of trust and humanity in a prison. A variation of it is used by Her Majesty’s Prison and Probation Service.

She’s also borrowed a technique she pioneered in prison research known as ‘appreciative inquiry’. To understand the culture of a prison she reverses the usual approach of asking prisoners about their offending. Instead she begins by finding out what they’re most proud of, their best experiences in prison, or about their life outside beyond criminal offending. It sounds a trifling thing, she says, but it changes the tone of the conversation.

Liebling professes never to have been frightened about entering a prison— she’s safer there than on the streets, she insists. She’s now been in almost all of England’s 120-or-so jails and never harmed. Perhaps her nonchalance is a product of her upbringing. Her father was a consultant psychiatrist and her mother a GP and psychotherapist: she recalls happily playing hide-and-seek with schizophrenic patients in hospital corridors whilst waiting for her father to finish work.

Her mother was Christian, while her father’s parents were Jewish immigrants from Eastern Europe, who sold linen from a stall. They belonged to Nottingham’s small but close-knit Jewish community. When her father married a gentile, his father (her grandfather) pretended for many years that his son was dead. Her parents had a horribly messy divorce when Alison was 10 and she lost touch with her extended Jewish family; she has only become reacquainted with them since her father’s death in 2016.

But she’s always retained a curiosity about her Jewish origins, and self-consciously kept her Jewish surname. A decade ago she found the names of very many Lieblings engraved on the wall in a Jewish cemetery. The cemetery was in Prague. “I feel that’s where I come from”.

David Edmonds (@DavidEdmonds100) is the host of Social Science Bites