The Interface Theory of Perception argues that what we perceive through our senses is not a true, objective reality. Instead, our perceptions are more like a desktop interface on a computer, shaped by natural selection to guide useful behavior, not to show us the truth.
This idea, detailed in a paper by Donald D. Hoffman, Manish Singh, and Chetan Prakash, challenges a long-held consensus in cognitive science. For decades, the prevailing view has been that our senses evolved to give us an accurate picture of the world. As one textbook states, “vision is useful precisely because it is so accurate. By and large, what you see is what you get”. The assumption is that organisms that see the world more accurately outcompete those that see it less accurately, thus passing on their genes for truer perception.
Evolutionary Games Reveal a Surprising Truth
To test this assumption, Hoffman and his colleagues used mathematical tools like evolutionary game theory and genetic algorithms. They created simulations where virtual organisms with different perceptual strategies competed for resources. The results were clear and consistent.
In these simulations, “veridical perceptions strategies tuned to the true structure of the world are routinely dominated by nonveridical strategies tuned to fitness”. In other words, seeing reality as it truly is makes an organism less fit and more likely to go extinct. Perception is tuned to payoffs that help an organism survive and reproduce, not to objective truth.
What is the Interface Theory of Perception?
The paper offers a powerful analogy to explain this finding: the user interface of a personal computer. Consider an icon for a text file on your desktop. It might be blue, rectangular, and in the corner of your screen. This does not mean the file itself, which is a complex collection of circuits and software, is blue, rectangular, or in the corner of your computer.
The icon isn’t meant to show you the reality of the computer. It’s designed to hide that reality to make the computer easier to use. The Interface Theory of Perception suggests our senses work the same way. “For the perceptions of H. sapiens, space-time is the desktop and physical objects are the icons”.
This leads to a common objection: if you see a snake and believe it’s just an icon, why not pick it up? Hoffman explains that we must take our perceptions seriously, but not literally. You take the file icon on your desktop seriously because dragging it to the trash can delete your work. Likewise, you take the snake perception seriously because it’s an icon signaling danger, which affects your survival. Evolution has shaped these icons to keep you alive.
A New Understanding of Illusions
The Interface Theory of Perception also reframes our understanding of illusions. The traditional definition of an illusion is a perception that is not veridical or true. But if no perception is ever a true depiction of reality, this definition fails.
Instead, Hoffman proposes that illusions are “perceptions that fail to guide adaptive behavior”. For example, the Necker cube is an illusion because it suggests a 3D object we could grasp, but we cannot. It provides misleading cues for action.
The Implications of an Evolved Interface
The theory proposes that everything we perceive, from a coffee cup to the fabric of space-time itself, is part of our species-specific interface. We are not seeing objective reality, but an adaptive fiction that helps us navigate it successfully.
Ultimately, the argument is a straightforward conclusion from the theory of evolution. As Hoffman and his colleagues write, “perception is about having kids, not seeing truth”. Our minds are not pipelines to the truth; they are survival tools, and the Interface Theory of Perception describes the rulebook they follow.