The Case Against Reality: Why Evolution Hid the Truth from Our Eyes

by Donald D. Hoffman

Evolution has shaped our senses to keep us alive. We have to take them seriously: if you see a speeding Maserati, don’t leap in front of it; if you see a moldy apple, don’t eat it. But it is a mistake of logic to assume that if we must take our senses seriously then we are required—or even entitled—to take them literally. I take my perceptions seriously, but not literally. This book is about why you should do the same, and why that matters. I explain why evolution hid objective reality and endowed us instead with an interface of objects in space and time. Together, we will explore how this counterintuitive idea dovetails with discoveries in physics that are equally counterintuitive. And we will examine how our interface works and how we manipulate it with makeup, marketing, and design.

The FBT Theorem tells us that the language of our perceptions—including space, time, shape, hue, saturation, brightness, texture, taste, sound, smell, and motion—cannot describe reality as it is when no one looks. It’s not simply that this or that perception is wrong. It’s that none of our perceptions, being couched in this language, could possibly be right.

Colors can trigger emotions and memories that enhance our fitness by guiding our actions. Corporations harness the power of color as a tool for branding, and will go to great lengths to defend a color as intellectual property. But as potent and evocative as color may be, “chromatures,” which are textured colors, prove far more versatile and powerful than colors alone, and for good evolutionary reasons. Chromatures can be designed to trigger specific emotions and associations. If you understand our codes for fitness, then you can intelligently hack them for your benefit.

But evolution is not done with our sensory codes for fitness. It still experiments with novel interfaces for our enterprising species. Four percent of us are “synesthetes” who perceive a world that differs from the norm.

Perception may seem effortless, but in fact it requires considerable energy. Each precious calorie you burn on perception is a calorie you must find and take from its owner—perhaps a potato or an irate wildebeest. Calories can be difficult and dangerous to procure, so evolution has shaped our senses to be misers. One consequence, we discover in chapter nine, is that vision cuts corners: you see sharp detail only within a small circular window, whose radius is the width of your thumb held at arm’s length. If you close one eye and hold out your thumb, you can see just how tiny it is. We think we see the whole field of vision in great detail, but we’ve been duped: each place we look falls into that small window of sharp detail, so we mistakenly assume that we see everything in detail. Only within that small window does your sensory interface construct a detailed report of fitness payoffs. That crucial report is formatted as the shape, color, texture, motion, and identity of a physical object. You create a suitable object—your description of payoffs—with a glance. You destroy it and create another with your next glance. Your wide field of vision guides your eyes to attend where there are vital payoffs to report, and thus an object to create.

Activity in a region of the brain called the postcentral gyrus correlates with conscious experiences of touch. The neurosurgeon Wilder Penfield reported in 1937 that stimulating this gyrus with an electrode in the left hemisphere prompted his patients to report conscious experiences of touch on the right side of the body; stimulating the right hemisphere led to feelings of touch on the left side of the body.13 The correlation is systematic: nearby points on the gyrus correspond to nearby points on the body, and regions of the body that are more sensitive, such as the lips and fingertips, occupy more real estate on the gyrus. Stimulate the gyrus near the middle of the brain, and you feel it in your toes. Slide the electrode along the gyrus, stimulating at ever more lateral points, and the feeling, with a few exceptions, slides systematically up the body. The exceptions are interesting. The face, for instance, resides next to the hand on the gyrus. The toes are next to the genitals—a fact perhaps relevant to foot fetishes, as V. S. Ramachandran has suggested.14

What false assumption bedevils our efforts to unravel the relation between brain and consciousness? I propose it is this: we see reality as it is.

Genes don’t elbow each other directly. They do it by proxy. They boot up bodies and minds—phenotypes—and let them duke it out. Phenotypes that fare better at the brawl are, like their respective genotypes, said to be fitter. The fitness of a phenotype depends, of course, not just on genes, but also on the vagaries of disease, development, nutrition, and the common depredations of time. Identical twins, for instance, can differ in their phenotypic fitness. But make no mistake: even though genes battle by proxy, they have skin in the game. Like pilots in a plane, genes sit strapped into their phenotype: if it crashes, they die.

But despite the consensus of experts, I doubted that natural selection favors perceptions that describe reality. More deeply, I doubted that selection favors perceptions that could even frame true descriptions of reality. It’s not that on occasion a perception exaggerates, underestimates, or otherwise goes awry, it’s that the lexicon of our perceptions, including space, time, and objects, is powerless to describe reality.

“Little did I realize that in a few years I would encounter an idea—Darwin’s idea—bearing an unmistakable likeness to universal acid: it eats through just about every traditional concept, and leaves in its wake a revolutionized world-view, with most of the old landmarks still recognizable, but transformed in fundamental ways.” —DANIEL DENNETT, DARWIN’S DANGEROUS IDEA

“If you ask me what my ambition would be, it would be that everybody would understand what an extraordinary, remarkable thing it is that they exist, in a world which would otherwise just be plain physics. The key to the process is self-replication.” —RICHARD DAWKINS, IN JOHN BROCKMAN’S LIFE

Darwin’s algorithm has been applied to fields such as economics, psychology, and anthropology. The physicist Lee Smolin applied it to the largest scale of all—cosmology—proposing that each black hole is a new universe, and that a universe more likely to produce black holes is more likely to produce more universes.8 Our universe has the properties that it does—such as the strengths of the weak, strong, gravitational, and electromagnetic forces—because they are conducive to creating black holes and, through them, new universes. Universes quite different from ours are less likely to produce black holes, and thus less likely to reproduce. The insight that Darwin’s algorithm applies not just to the evolution of organic beings but also, with some changes, to a variety of other domains, is called universal Darwinism.9 (Richard Dawkins coined the term when arguing that Darwin’s algorithm governs the evolution of life not just on earth but anywhere in the universe.) Universal Darwinism, unlike the modern theory of biological evolution, does not assume the existence of physical objects in space and time. It is an abstract algorithm, with no commitment to substrates that implement it. Universal Darwinism can, without risk of refuting itself, address our key question: Does natural selection favor true perceptions? If the answer happens to be “No,” then it hasn’t shot itself in the foot. The uncanny power of universal Darwinism has been likened by the philosopher Dan Dennett to a unive...

Darwin’s idea of natural selection entails the FBT Theorem, which in turn entails that the lexicon of our perceptions—including space, time, shape, hue, saturation, brightness, texture, taste, sound, smell, and motion—cannot describe reality as it is when no one looks. It’s not simply that this or that perception is wrong. It’s that none of our perceptions, being couched in this language, could possibly be right. The FBT Theorem runs counter to strong intuitions of experts and laymen alike. Dennett was right—Darwin’s idea is a “universal acid: it eats through just about every traditional concept, and leaves in its wake a revolutionized world-view, with most of the old landmarks still recognizable, but transformed in fundamental ways.”