Exploring the evolution of color perceptions, Elijah Wolfson considers how our ability to see red sets us apart from other mammals:
Most mammals, including most primates, are dichromatic, meaning they can only detect two color wavelengths: green and blue. Certain primates, though, have evolved to see a third: red. It turns out that these primates—humans, chimps, gorillas, and orangutans, to name some—all have one thing in common: bare-skinned faces. Based on this trend, experts have hypothesized that the development of trichromatic vision was, in fact, the result of an evolutionary advantage that certain primates had over others: namely, that it helped our ancestors better understand the emotional states, socio-sexual signals, and threat displays of their brethren.
The upshot was huge. Once we could actually see the red that coursed through our veins, it became a secondary communication tool: ovulating females would redden in the face and in their sexual organs to signal sexual readiness; angry males displayed dominance by reddening in the face. Modern humans might still get red in the face while angry, but we’ve also branched out to using signaling tools like cocktail dresses and soccer jerseys. While the medium has changed, the message remains: displaying red means you’re serious.
The Dish 