We see with our ideas. That idea can open our eyes to key questions about modeling human nature. Varying blues and illusions illuminate a weird sampling error at the heart of a heartless economic worldview. And suggest a fix. To see how deeply ideas influence what we see, consider that: Russians have blues, but no blue. They have no single word for our color blue. Their language makes "an obligatory distinction between" lighter blues (goluboy) and darker blues (siniy). Their idea that these are separate colors means Russians distinguish them faster than English speakers can. Daniel Kahneman, a leading behavioral economist, says of the Muller-Lyer optical illusion (Fig 1) that even after it is explained, "we all see" one line as "obviously longer." And makes an analogy with "illusions of thought" or cognitive biases--"systematic errors" that cause deviations from supposedly rational choices. But we don't all see it that way. Some non-industrialized cultures don't fall for the illusion. One suggestion is that they don't see converging straight lines as box-like perspective. But whatever the reason, susceptibility to the Muller-Lyer varies by culture. Could cognitive biases also vary by culture? Though de-anthropomorphizing human behavior can be risky, technomorphic thinking--projecting technological features onto humans--can help here. Are cognitive biases mostly hardware flaws and cross-culturally consistent (like the physiological blind spot you're ignoring as you look at this)? Or are some bugs in our culturally configured software? Like Kahneman's view of the universality of the Muller-Lyer illusion, the rational-agent model of human nature, which dominates economics, is based on a sampling error. Globally the "Western self...is a rather peculiar idea." Models of it are based on overwhelmingly WEIRD (western, educated, industrialized, rich and democratic) research. But most humans aren't all WEIRD. Not yet. Human hardware and software evolved for 10,000 generations to fit team survival strategies. The unchecked and imbalanced individualism that many economists now consider natural and rational, was "a novel expression" in Tocqueville's time (too recent for a hardware upgrade). That idiotic (idios meant private and overly self-oriented) idealization is unrepresentative, "cognitively unnatural," and ignores that we evolved to be self-deficient and relationally rational. It's distorted "rationality" often prioritizes short term transactional self-maximization that can produce self-undermining outcomes (as in Prisoners' Dilemmas or Tragedy of the Commons situations). No really rational self-interest should fall for illusions of thought that are so foreseeably at odds with ultimate self-preservation. Economic models of human nature should be, like us, a complicated balance of individual and socio-centric interests. They can fruitfully incorporate more ideas about interdependent success (like evolution's inclusive fitness). Our ideas must help us see clearly that it can't be deemed rational to damage what you depend on. Illustration by Julia Suits, The New Yorker Cartoonist & author of The Extraordinary Catalog of Peculiar Inventions. Previously in this series: Kahneman and Bentham's Bucket of Happiness Kahneman's Clarity: Using Mysterious Coinage in Science What Rational Really Means The Cognitive Science of Star Trek Colonoscopies Clarify Inner Workings of Minds Happiness Should Be A Verb Better Behaved Behavioral Models Rationality In Markets Is Cognitively Unnatural The Limits of Psychophysics, And Physics