London - Graffiti, litter and broken windows don’t just look bad - they can have an ugly impact on people living nearby.
Residents living in a litter-strewn environment can become more racist and homophobic as well as less charitable, scientists found.
Prejudice is often a reaction to the disorder and chaos around them, they concluded.
The findings follow previous studies which found that litter, vandalism and graffiti increased anti-social behaviour.
Anti-litter campaigners welcomed the latest research and called for a cleaning up of towns, cities and the countryside.
For the study, researchers in the Netherlands looked at the impact of scruffy streets and dirty train stations on people’s attitudes.
In one test, they used a cleaners’ strike at Utrecht railway station to test white passengers’ views about Muslims, gays and other travellers.
After the station had not been cleaned for days, 40 people were asked to fill in a questionnaire in an area with six chairs in a line.
In the first sat a black or a white actor and the passengers could choose which other chair to sit in.
A week later, after the station had been cleaned, the experiment was repeated, said a report in the journal Science.
When the station was dirty, the passengers showed more prejudiced views than when it was clean. They also sat further away from the black man.
In a second test, 47 passers-by were stopped in an affluent area and asked to fill in a questionnaire. They were also invited to donate to a Money for Minorities charity.
Before the survey, the scientists removed tiles from the pavement, parked a car with open windows and two wheels on the kerb and abandoned a bicycle in full view.
A day later, they repeated the experiment but this time replaced the tiles, removed the bike and parked the car properly.
People were more prejudiced and less likely to donate money when the street was scruffy, they found.
Researchers said disorder makes the mind crave structure. One way to create order is to put other people into neat boxes based on their skin colour, religion or sexuality.
Dr Diederik Stapel said: “Stereotyping is a mental cleaning device to cope with physical chaos.
“The message is clear. Signs of disorder will not only increase anti-social behaviour but lead to stereotyping and discrimination.” - Daily Mail