Red is everywhere – celebrities walk the red carpet, politicians wear red ties, and lots of sports teams wear it. There have even been studies showing that the same person is perceived as being more attractive when wearing red.
The question is, why? What’s the biological explanation for this?
In: Biology
Human vision evolved to be most sensitive to green, probably because 90% of nature is green due to chlorophyll, and being sensitive to green makes it easier to discern things that don’t belong, like venomous snakes. Many other animals seem to have similarish vision.
Red stands out from that. Plants use red to stand out with flowers and fruits that are designed to attract pollinators and animals to eat the fruit and spread the seeds. That’s why so many berries are red. Many poisonous or venomous animals with [aposematic colors](https://en.wikipedia.org/wiki/Aposematism) are red to stand out. Red is also the color of our blood, and we’ve evolved to notice blood, both coming from ourselves and from prey.
That’s why stop signs are red and stop signals are red and warning signs are red. We already know deep in our subconscious that red is important. It could be food or it could be danger, but it’s something we need to pay very close attention to.
Blue might also stand out, but blue is a lot harder to make for physics reasons. Most things (but by no means all) in nature that appear blue do not use a blue pigment, but instead have complex microscopic structures that scatter light to appear blue just like the sky. That is, they don’t absorb the other colors and reflect blue, the way that pigments do, but rather they work like tiny prisms to split the different colors apart and then only send blue towards you. That’s a lot of work. It pays off for the organisms that do it, but it’s difficult and, as a result, fairly rare in nature.
Our color vision is quite good and we’re capable of detecting blue, but it’s somewhat weaker than our red perception, which itself is significantly weaker than our green perception.
So, basically, our vision evolved to look for very subtle differences in green, and then to notice things that are definitely *not* green, which are usually red.
Latest Answers