Book Review: Spent: Sex, Evolution, and Consumer Behavior by Geoffrey Miller

“Marketing is not just one of the most important ideas in business. It has become the dominant force in human culture.” This is how evolutionary psychologist Geoffrey Miller leads into an early chapter on the importance of marketing. In spent, Miller sets out to explain why humans buy the things they do. His perspective is based on the concept that compared to the time it took humans to evolve, our consumer society is so new that our brains are applying the skills developed for hunter-gatherer communities and applying them today. When we buy a Toyota Prius or Coach purse, we are still engaging in behaviors honed over the millenia on the veldt and in the forests.

I found the most valuable insights in Spent in the first half. In a discussion of what he terms consumer narcissism, Miller succinctly states the underlying premise of the book:

…All human brains have a deep and abiding interest in two big sets of evolutionary goals: displaying fitness indicators that were associated with higher social and sexual status in prehistory, and chasing fitness cues that were associated with better survival, social, sexual, and parental prospects in prehistory.

In short, we want to present ourselves as “fit” (in a broad sense) while seeking out other “fit” individuals. Fitness can be not just physical, but also social. Our underlying evolutionary goal is to ensure our DNA survives into the future. In today’s society, we engage in behaviors like cosmetic surgery and philanthropy for reasons that seem to have little to do with DNA survival; these, Miller posits, are the way we adapt our primal programs to today’s opportunities and demands.

Miller explains conspicuous consumption as an indicator of fitness. Not unlike a male peacock that devotes a large portion of its energy resource to growing a tail with no practical survival applications, humans who “waste” resources demonstrate to others that they are “fit.” Only a fit individual of the species could, the theory goes, waste so many resources and remain healthy; a sickly peacock, for example, would likely be unable to grow an impressive tail.

If you like consumer and brand stereotypes, Spent is full of them. Miller uses a plethora of brand examples to show how consumers who buy these brands signal things about themselves. He notes that a Hummer is an example of “conspicuous waste,” while a similarly expensive Lexus sedan is a badge of “conspicuous precision.” A BMW, meanwhile, denotes “conspicuous reputation.” (Miller mentions the Hummer brand so often I’m expecting a follow-on volume titled, The Psychopathology of Hummer Owners.)

The second half of the book loses momentum when it delves into a discussion of what he terms the “Central Six” personality traits, consisting of “general intelligence” and the “Big Five:” openness, conscientiousness, agreeableness, stability, and extraversion. Miller states that these traits are what all consumers try to display, and that individuals vary considerably in their unconsciously chosen traits. Amusingly, Miller gives bumper-sticker examples of these traits: “Question reality” (high openness), “God bless the whole world. No exceptions” (high agreeableness), “Eagles Don’t Flock” (low extraversion), and dozens more.

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If marketers paid more attention to these traits and how their brands signaled them, they would have a better grasp of consumer behavior and know how to better design, market, and advertise their products. Miller spends a chapter each on intelligence, openness, conscientiousness, and agreeableness, but skims over stability and extraversion.

Overall, I liked Spent because I believe Miller is quite right about the fundamental influence of evolution on consumer behavior. We ignore that at our peril. Miller leavens the text with plenty of humor, though I wouldn’t term Spent to be a continuously easy read. Although Miller doesn’t hesitate to fill in with conjecture when hard research data isn’t available, much of what he says will make sense to experienced marketers. Evolutionary psychology can offer marketing insights, and I look forward to Miller and others pressing forward in linking these seemingly disparate fields.