Historians at York University are trawling 200 years of court records to understand the decline in homicide rates in the 17th century.
According to Jim Sharpe, professor of history at York, homicide rates in Britain were close to eight per 100,000 in the early 17th century, but dropped dramatically in the second half of the century and carried on falling in the 18th century to close to their current levels of one per 100,000.
Professor Sharpe and Roger Dickinson, a research fellow in history, are studying court cases heard in Chester. Most previous court work has looked at records from the south-east, but despite regional differences, the huge homicide decline appears to be a national phenomenon.
Perhaps half of the early casualties were because of less advanced medical interventions, said Professor Sharpe. "From the standard historical models, it's difficult to connect social and economic changes to what is going on with the homicide figures in this period.
"But I am playing with the idea that psychological controls over criminal behaviour were not so strong as now. There may be various processes beginning to bite which made people less likely to kill each other." These could include changes in family life, the spread of religion and improved standards of living for those at the bottom of society.
However, Professor Sharpe says that homicide in the 17th century was not restricted to the poorer classes. "Violent behaviour was widely diffused socially," he says. "What we would expect is a retreat in the 18th century of landowners and their urban equivalents from homicidal behaviour.
"It is all very tentative at the moment. But a serious historical study may help inform our understanding of what goes on in our society today, as well as shining light on other societies which are developing today in a way that is analogous with 18th-century Britain."