Teaching prisoners Socrates and Plato helps them develop empathy and tolerance, a study has found.

The programme, run by Dr Kirstine Szifris of Manchester Metropolitan University, found that terrorists, murderers and drug dealers became more tolerant and empathetic following a series of sessions on the classical Greek philosophers as well as later writers such as Kant and Descartes.

The initiative was designed to challenge "hyper-masculine survival behaviour" in the prisons, including among the most serious offenders.

Dr Szifris, who is presenting her research at the British Sociological Association’s annual conference in Newcastle today, said the lessons got off to a difficult start.

"The first half of the course felt like a battle," she said. "They could often be aggressive, accusatory and confrontational. The lack of positivity meant that I left the prison at the end of each day feeling exhausted and emotionally drained. I found these first few weeks difficult."

The 12-week curriculum at two prisons, Full Sutton prison in Yorkshire and Grendon prison in Buckinghamshire, included discussion of Plato’s ideal society, the Stoic philosophy of the Greeks and Romans, and the Socratic method of inquiry.

Students included the toughest Category A prisoners whose behaviour was initially characterised by "bravado, one-upmanship and competition".