Research shows that street furniture, barriers, parks, public spaces and neighbourhood architecture can stir up powerful emotions in local residents. This should be taken into account in programmes designed to reduce tensions and foster community cohesion.

Four cities - Amsterdam, Beirut, Belfast and Berlin were chosen as the location of the research as each has a different social history and underlying tensions. The project was undertaken by Dr Ralf Brand of the University of Manchester and was funded by the Economic and Social Research Council (ESRC).

Dr Brand found that tensions between different social groups (ethnic, religious or political in nature) and radicalisation can have a significant impact on the urban landscape, and vice versa. This does not mean that urban environments cause, or prevent, these political positions. But some architectural and urban design features were identified that at least played a part in raising community tensions as well as those that reduced divisions.

Radicalisation of different groups in cities is usually viewed as a political issue, as well as one of community cohesion and the circumstances of the people in the community, such as the level of deprivation. "It's essential to take these factors into account, but good urban design and architecture should not be overlooked," says Dr Brand. "A better built environment will not in itself make problems disappear, but it should be part of community action plans."

Dr Brand operated with the assumption that finding ways to bring people together has the potential to reduce problems and tensions, but he gives a warning, "Any attempt to lure people to artificially created shared spaces is ethically problematic and risky because they can alienate certain groups. It's important that both social and material changes should go hand in hand in urban communities."

A great deal of effort has been made to 'harden' access to potential targets of attack. For example, bollards are often installed to protect vulnerable facilities. Recently, urban designers have been trying to hide such measures to make them less visible. However, Dr Brand suggests that, while it is good to tone down protective barriers, they can still create a disturbing atmosphere.

He explains, "it's not just about taking measures to prevent bad things from happening in our cities, we need to foster good things too: bring people together; break down stereotypes and tackle segregation."

During the project, Dr Brand noted that in an effort to bring local residents on to the streets, authorities in Amsterdam installed a large chessboard in a public square. People were attracted to the area and playing chess in public has helped create a positive atmosphere.

"I'm not saying giant chessboards everywhere are the solution for reducing tensions in communities, but they illustrate the type of initiative we should be thinking about."

Findings from the research are helping policymakers, planners, architects, urban designers and ordinary citizens create urban areas that contribute to the friendly encounter of different groups of people. Dr Brand believes this will help tackle stereotypes, polarisation and radicalisation in communities.