Universiteit Leiden

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More accommodating prison regime leads to less aggression

Aggressive behaviour among prisoners decreased significantly following a number of adjustments in the daily regime at a penal institution. This has been established in an evaluation conducted by Tilburg University and Leiden University of an experiment with an alternative detention regime.

Marike Knoef

The study was conducted at Penitentiaire Inrichting (PI) Nieuwegein by Ben Vollaard (Tilburg University), Marike Knoef (Leiden University) and Tom van Dijk, a self-employed consultant. It was established that aggressive behaviour among prisoners can be significantly reduced when they are given more autonomy and more opportunities for contact with the outside world. Compared to prisoners held under the standard regime, a drop of 60 per cent in aggressive behaviour was observed in the prisoners held under the alternative regime.

The study has received much attention in the national media. See overview here.

One wing of the PI where the research was conducted operated under the new regime; an identical, fully separate, wing retained the standard regime. Data for the research came from more than 1000 prisoners who throughout a period of almost two years were arbitrarily assigned to one of the two wings at the institution. Half way through this period, the new regime was started. As a result of the arbitrary assignment of prisoners to the two wings, the group of prisoners under the new regime could be compared to the group under the standard regime.

The prisoners in the alternative regime are required to demonstrate more initiative, having to consider themselves what to do and when. For instance, they cook their own food and order their own groceries. They are also given a pass which they can use to go to work and sport activities. Finally, they have a key with which they have the responsibility to lock their cell from the outside during the recreation period. Prisoners in the alternative regime also had more opportunities to have contact with the outside world, by having a phone in their cell and the availability of a hospitable area for receiving visitors. Using the phone in their cell, prisoners were allowed to make calls, at their own expense, between 6.00 am and 10.00 pm, with the exception of blocked numbers.

The changes in the regime led to a reduction of 60 per cent in the number of aggressive incidents involving prisoners that were registered by prison staff. A strict regime would appear to be a good way of keeping prisoners on a tight leash, but ultimately it leads to more, instead of less, undesirable behaviour.

Crime and social welfare

'My contribution involved data collection, analysis and the reporting', Professor of Empirical Microeconomics Marike Knoef explains. 'I study the behaviour of people and households using quantitative methods, in the area of pensions, savings, and the labour market, but also in relation to crime and social welfare. At the Department of Economics, for example, I am supervising a PhD student together with the Department of Criminology. We are investigating, for example, the effects on youth crime in relation to reductions in the social welfare, and how crime increases throughout the entitlement month as a result of financial pressures. By the end of the month, these people often have no money left.'

Previously she evaluated an experiment concerning single mothers on benefits. 'On the basis of that expertise, I became involved in the experiment at the PI in Nieuwegein.'

Click here to access the Dutch report Het effect van een alternatief detentieregime op gedrag en gezondheid van gedetineerden (the effect of an alternative detention regime on the behaviour and health of prisoners).

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