In my part-time alternate life as a consultant, I have often pondered why a person chooses to buy a Billabong sweatshirt as opposed to a Quiksilver one. The choice is not an obvious one. The products themselves are essentially the same. The name is the only real difference. The gradient between one and the other is an infinitesimal pattern of grey, yet the decision — and millions more exactly like it — happen everyday.

Jonah Lehrer has emerged over the past few years as neuroscience’s strongest and most interesting voice. His Proust Was a Neuroscientist (Houghton Mifflin Harcourt, 2007) is as smart and fun a mix of the Two Cultures as you’re likely to find. With his spot as Seed Magazine‘s Editor at Large and a contributing editor gig at Wired, Lehrer is poised and positioned to inform the public about brain science like few others ever have been.

With How We Decide (Houghton Mifflin Harcourt, 2009), Lehrer turns his attention to the marketplace and how our brain power influences our buying power. Peter Merholz wrote that it was clear that Lehrer had “attended the Gladwell school of non-fiction writing, anchoring his facts in stories.” Maybe it was a compliment, but having recently read Gladwell’s latest book (the sometimes quite interesting but ultimately nearly pointless Outliers), I prefer Lehrer’s prose. It’s clear, concise, and lyrical, and at least I know there’s some science behind it.

The traditional wisdom says that we make important decisions by relying on the rationality of the logical brain to override the “animal stuff” (as Howard Bloom calls it) of our emotions and instinctual drives. In How We Decide, Lehrer contends that the process is a bit more nuanced than that. It’s a subtle dance, a process of bend and blend that depends on the situation. Well, it’s not quite that simple either, but Lehrer’s book often makes it all seem so. It ends with a “taxonomy of decision-making,” which helpfully applies many of the book’s anecdotal dilemmas to practical, real-world situations.

Coming to the brain and purchasing decisions from a different angle, Geoffrey Miller’s Spent: Sex, Evolution, and Customer Behavior (Viking, 2009) argues that it’s all just so many peacock feathers. Miller is an evolutionary psychologist, so his lens is longer than Lehrer’s, but doesn’t mean he sees the situation any clearer or in higher relief. Like Lehrer, he writes to be read, but where Lehrer’s prose is positive, Miller’s negativity seeps into his sentences. His wit is by turns playful and biting, veiling and betraying a deep-seated cynicism toward the consumer capitalism he’s analyzing.

Miller writes like he’s the first academic to discover the field of marketing, as if Stewart Ewen, Douglas Rushkoff, and Marshall McLuhan (!), among many, many others hadn’t already upturned similar soil. In addition, his arguments smack of psychoanalytic reasoning (i.e., many of our purchasing decisions are driven by the libido and thereby illustrate material sublimation, many others are driven by narcissism, etc.) dressed up in evolutionary garb: We buy stuff to advertise our potential to each other as possible mates, sexual and Platonic. It’s certainly not all bad or bland though. Miller’s idea of “fitness faking” (about which I’ve written before) makes a brief appearance, and his “Exercises for the Reader” (similar to Lehrer’s concluding taxonomy) are a nice touch of pragmatism more science books could use.

After having read both of these books, I don’t feel any closer to understanding the Billabong/Quiksilver dilemma, but as Miller writes on the very first page of Spent, echoing McLuhan, “consumerism is hard to describe when it’s the ocean and we’re the plankton.”