“Is your red the same as my red?”

A question that middle-schoolers and high-schoolers ponder in jest actually has some profound applications to perception.

“Is your red the same as my red?”

Perception is this in-betweeny thing that exists between reality, in this case the color red, and your interpretation of reality, what you perceive as red.

Now, we can make all sorts of measurements and claims to try to circle around a definition for reality-red. We know that red is the color of light with a wavelength in the 620-750 nm range. Firetrucks are red. A ripe strawberry is red. Most fires are red (although the really cool ones are not).

But all of those claims are tautological. They’re circular definitions that don’t actually reveal anything about perceived-red. There is no way for anyone to know whether the color red that you perceive is the same as the color red that someone else perceives.

To illustrate, imagine an alien species landed on Earth and lived among us 3rd Rock From the Sun style - long enough for them to understand all our examples and idioms, but not so long that I feel obligated to derail this illustration with the geopolitical or bio-psycho-social ramifications of an alien/sapien world.

These aliens are mostly the same as us. They have eyes with optical nerves that convert light into signals for their brain. Except for one crucial difference: in this alien species, blue and red are flipped. Light in the 620-750 nm range (reality-red) gets transmitted through their optical nerves, but looks blue to them.

Would any of our claims about red expose this difference?

  • “It’s the color of a firetruck.”
  • “It’s the color of a ripe strawberry.”
  • “It’s a warm color, like fire.”
  • etc.

No! Despite their completely inverted perception, these aliens could fully participate in our language about color. They would agree that firetrucks and strawberries are “red,” even though what they actually experience when seeing these objects is what we would call “blue.” They would learn our associations between “red” and “warmth” or “danger,” and use the word correctly in every context, despite experiencing a fundamentally different sensation.

And we would never know. There would be no test, no experiment, no conversation that could reveal this profound perceptual difference. Both humans and aliens would go about their lives, using identical language to describe fundamentally different experiences of reality.

This isn’t just a philosophical thought experiment about color. It illustrates something essential about perception itself: the unbridgeable gap between our subjective experience and objective reality.

Now, none of this is surprising. We know there’s an in-betweeny thing, a type of lens, between reality and our brains.

But usually, when confronted with the topic of perception, people don’t give it a second thought. They think it’s synonymous with a bias or viewpoint. This couldn’t be further from the truth. Perception is so much more. And recognizing perceptions constituent components is essential to thinking clearly in our complex world.