How evolutionary psychology reveals the ancient instincts driving modern consumer behavior
What would an alien anthropologist think of Earth's shopping malls? They'd see humans obsessing over luxury watches, artisanal coffee, and the latest smartphones—many items with little apparent survival value.
Through a logical lens, our consumer choices often seem irrational. Why pay a premium for a branded T-shirt virtually identical to a cheaper alternative? Why queue for hours for the latest gadget? The answer lies not in the practical utility of these items, but in what they communicate about us. According to evolutionary psychologist Geoffrey Miller in his provocative book Spent: Sex, Evolution, and the Secrets of Consumerism, our shopping habits are a modern performance of an ancient play: we use products to silently signal our desirable traits to potential mates, allies, and rivals 1 4 .
Consumerism, Miller argues, is the continuation of mating displays by other means 4 . Our brains, honed by millennia of evolution, are operating in a context radically different from the environment they were designed for. The same instincts that once led us to admire a symmetrical face or a skillfully crafted tool now draw us to minimalist design and luxury brands 1 .
To understand Miller's argument, we must first look beyond Darwin's famous theory of natural selection—the "survival of the fittest"—and consider his second great theory: sexual selection 1 . Natural selection explains how animals evolve traits that enhance survival, like camouflage to avoid predators. Sexual selection, however, explains the development of traits that seem to hinder survival but enhance mating success.
The classic example is the peacock's tail 1 . This magnificent but cumbersome plumage offers no survival advantage; in fact, it makes the peacock more visible to predators and consumes vital energy. Its sole purpose is to attract peahens. It is a "costly signal"—precisely because it is so burdensome, it honestly demonstrates the peacock's superior genetic fitness. Only a truly healthy, robust individual can afford such an extravagance 1 .
Miller proposes that much of human consumer behavior is the human equivalent of the peacock's tail 4 . We engage in "conspicuous consumption," a term coined by economist Thorstein Veblen, to advertise our qualities to others 3 .
A luxury handbag, a high-performance sports car, or a meticulously curated vinyl collection often serves less a practical function and more a social one: to signal our health, resources, intelligence, and good taste 3 4 . As Miller writes, "Every visible purchase is an ad campaign for your genes" 4 .
If consumerism is about signaling, what traits are we so desperate to show off? Miller points to the "Central Six"—a set of universally recognized, heritable, and stable personality traits that are highly valued in social and mating contexts 1 4 6 .
What It Signals: Problem-solving ability, adaptability
Consumer Example: Owning a library of literary novels; using complex tech gadgets 4
Miller posits that marketers, though rarely trained in evolutionary science, are master intuitive psychologists 4 . They understand our deep-seated desire to display these Central Six traits and create brands that serve as powerful, shorthand signaling tools.
A brand that tries to appeal to everyone signals nothing and holds little power. Powerful brands, therefore, align themselves with specific personality profiles 1 . For instance, Apple products are often marketed as tools for the creative and intelligent, allowing users to signal their "cognitive style" 4 . Patagonia gear signals both conscientiousness (quality, durability) and agreeableness (environmental responsibility). The entire luxury goods industry is built on the principle of "costly signaling"—the high price is the point, as it demonstrates the buyer's access to abundant resources 3 4 .
Successful brands target specific personality traits rather than trying to appeal to everyone
Miller provides a fascinating, concrete example of how products signal personality by analyzing the automobile market 1 . He segments various car brands based on the personality traits they most commonly project to others. This research offers a clear window into how our consumer choices function as a non-verbal language.
This analysis is based on consumer perception data and branding research that links specific car makes and models to the six key personality traits. By aggregating how populations perceive these brands, patterns emerge that go beyond mere transportation utility and reveal the signaling function of our vehicles 1 .
The data shows that cars are not just modes of transport but "mobile billboards for our personas" 3 . The traits we signal through our car choice can influence how we are perceived in social hierarchies and even in mating markets.
| Personality Trait | High-Scoring Car Brands | Low-Scoring Car Brands |
|---|---|---|
| General Intelligence | Acura, Audi, BMW, Volkswagen 1 | Cadillac, Chrysler, Dodge, Hummer 1 |
| Openness to Experience | Lotus, Mini, Scion 1 | Buick, Lincoln, Rolls Royce 1 |
| Conscientiousness | Acura, Honda, Toyota, Volvo 1 | Ferrari, Jeep, Mitsubishi 1 |
| Extraversion | Aston Martin, BMW, Ferrari, Mini 1 | Acura, Hyundai, Saab, Volvo 1 |
| Agreeableness | Acura, Daewoo, Kia, Saturn 1 | BMW, Hummer, Maserati, Mercedes 1 |
| Neuroticism (vs. Stability) | Volkswagen, Volvo 1 | Acura, Porsche, Scion 1 |
This "experiment" in consumer perception demonstrates that we have a shared, if unconscious, understanding of what products represent. Choosing a car is, in a very real sense, choosing which parts of your personality to broadcast to the world.
For those looking to understand or even apply the principles from Spent, the "toolkit" consists of key conceptual frameworks. The table below details these essential mental models and their functions in analyzing consumer behavior.
| Conceptual Tool | Function |
|---|---|
| Signaling Theory | Provides the core framework for understanding how any costly or hard-to-fake action (like a purchase) acts as an honest advertisement of underlying qualities 3 . |
| The Central Six Traits | Offers a validated, evidence-based model of human personality that serves as the "content" of the signals we send, replacing outdated marketing demographics 1 4 . |
| Costly Signaling | Explains the economic and psychological value of waste and precision. Inefficient signals (luxury goods, artisan crafts) are powerful because they are hard to fake, proving genuine access to resources or skill 4 . |
| Conspicuous Consumption | Describes the visible, status-oriented consumption that functions as a modern display of fitness, much like a peacock's tail or a bowerbird's nest 3 4 . |
While Miller's analysis might seem cynical, his ultimate goal is empowering. He highlights the "fundamental consumerist delusion": the belief that others care more about our possessions than our innate traits 4 6 . We think a new luxury car will make us appear more intelligent or attractive, but in reality, people are far more influenced by our actual humor, kindness, and intelligence displayed through social interaction 4 . This disconnect between the signal and the true self is a primary source of consumerism's emptiness.
"Every visible purchase is an ad campaign for your genes." - Geoffrey Miller 4
The good news is that understanding these hidden forces allows us to become wiser consumers and happier individuals. Miller suggests several alternatives to mindless consumption for signaling 4 6 :
Stronger communities and richer social interactions provide more meaningful avenues to display our traits than shopping ever can 6 .
Making things yourself, buying used, or commissioning work from local artisans can display creativity, resourcefulness, and community connection more effectively than an off-the-shelf luxury item 6 .
Experiences often provide richer stories and more genuine connections to others than material goods, offering higher "narrative value" 4 .
By recognizing that our spending is often a misguided attempt to display our inner selves, we can refocus our energy on actually developing those valued traits—intelligence, openness, conscientiousness—and expressing them through our actions and relationships, not just our possessions. In doing so, we can escape the "hedonic loop" of consumerism and spend our time, energy, and money on things that truly lead to a fulfilling life 4 .
References to be added separately.