In 1999, a busy street in Glasgow, Scotland, had blue lights installed for the pedestrian traffic. The original purpose of the new lights was to liven the rea and create a point of difference for the area, as part of a neighborhood enhancement project.

What they didn’t expect was a notable drop in crime, which followed after the blue lights were installed. A similar situation occured in Japan sometime after the crime quelling results of Glas-glow, when blue lights were installed at train stations – a suicide hot spot. The advent of suicide dropped drastically following the replacement of traditonal lighting.

But why would blue light change deter someone from crime or suicide? There are a couple of interesting hypothesis surrounding behaviour and environment that could shine some light on this interesting phenomena.

Blue has almost universally been accepted as a calling card for police presence, the colour has been appropriated by the police in much of the Western world.

People are generally uncomfortable in unfamiliar surroundings. The uncommon blue lighting means people don’t know what to expect and will resist committing a crime in such circumstances. Whether or not this feeling wears off after some time, is open to research. A study in 2011 stated that crime was still much lower than 1999 figures in the Glasgow street.

Humans respond better to blue as an illuminating colour as was shown by Lewinski (1938). Another study found that blue illumination saw a decrease in the stress responses of fish.

Whether or not these findings are enough to see the change of every light in Sydney to blue is another conversation, as most of these findings could be outdated since their 2008 studies.

What do you know about blue light? How quickly could you disprove these findings? Let us know in the comments.