[JFlash]

Great comment. This reasoning is probably intuitive to anyone who's familiar with a logographic writing system.

I feel like you can also draw a parallel with programming languages. Consider:

  def sum1(array)
    sum = 0
    array.each { |e| sum += e }
    sum
  end

  def sum2(array)
    array.reduce(:+)
  end

sum2 isn't just a different way to write the same thing. It's a construct that expresses a specific pattern of evaluation and aggregation. It doesn't describe what it's doing like sum1 does. It's more expressive than that. It's "clearer" once you learn it.

Similarly (at least in the US) green means proceed/go/forward/continue and red means cancel/go back/stop/error. This is something that was learned, not something that was known by instinct.

[kqr]

> red means cancel/go back/stop/error. This is something that was learned, not something that was known by instinct.

Well...[1][2] There are some precedents for red being a no-go colour even in nature. Which is likely why we use it as a stop colour. It would be interesting if someone knows of a significant number of cultures that use it as a "go ahead" colour. I mean, the samples are probably skewed because everyone has been a colony these days but still.

[1]: http://www.noaa.gov/features/resources_0109/images/fire1.jpg [2]: http://museumvictoria.com.au/spidersparlour/images/en000008....

[marcosdumay]

Transit lights were standardized during the XX century. You won't find a place that uses them differently.

But there are cultures where red means good things.