So many of the products we see around us defy common sense. I’m not talking about the “What do vegans eat at Christmas?” craziness of the Tofurky. Or even the unrealistic-fear-of-germs obsessiveness of the antibacterial chopping board.

Rather, I’m talking about the flashiest manifestations of attention-grabbing consumerism. Designer label clothes, heavy bling, flashy cars and chunky Swiss watches. These products embody what the early economist Thorstein Veblen labelled “Conspicuous Consumption” – products whose main value is to signal the owner’s wealth and status.

Evolutionary psychologists have lately grown animated about the similarities between conspicuous consumption and the flashy status and mating signals used by other animals. Geoffrey Miller devoted much of his 2009 book Spent: Sex, Evolution and Consumer Behaviour to the ways we signal via our consumption patterns.

Miller asks:

Why would the world’s most intelligent primate buy a Hummer H1 Alpha sport- utility vehicle for $139,771? It is not a practical mode of transport. It seats only four, needs fifty- one feet in which to turn around, burns a gallon of gas every ten miles, dawdles from 0 to 60 mph in 13.5 seconds, and has poor reliability, according to Consumer Reports. Yet, some people have felt the need to buy it— as the Hummer ads say, “Need is a very subjective word.”

The answer, according to Miller, is that apart from the starkest necessities, most of the products we buy are purchased to signal our status, intelligence and personality traits. Our need to do so evolved long before the products themselves existed, and the best brands and marketing campaigns (think Apple, BMW and Rolex) tap into these evolved needs.

Today we ornament ourselves with goods and services more to make an impression on other people’s minds than to enjoy owning a chunk of matter—a fact that renders “materialism” a profoundly misleading term for much of consumption. Many products are signals first and material objects second.

Conspicuous consumption is one of the many areas of research in which evolution and economics collide. And recently Jason Collins, who runs the amazing Evolving Economics site, posted a working paper Sexual Selection, Conspicuous Consumption and Economic Growth in which he explores the how an evolved tendency to signal via conspicuous consumption might contribute to economic growth.

Collins models the relatively simple situation in which men signal their quality as potential mates to women via conspicuous consumption. As he explains on his own blog:

To engage in conspicuous consumption takes effort by the men – whether in the form of art, humour or entering the labour force to acquire resources to consume conspicuously. As the prevalence of males who conspicuously consume increases, the total level of these activities also increases. The increased participation in productive activities results in a scale effect, whereby the greater number of people involved in creative and productive activities results in increased technological progress, which underlies economic growth.

I’m not well equipped to dissect the modelling, but I find the idea profoundly interesting. Of course signalling via conspicuous consumption isn’t confined to single men. I’m not the only one who thought the entire Sex and the City franchise was little more than an elaborate exercise in product placement.

But evolutionary biology is replete with models of flashy males signalling to choosy females, and it provides an excellent place to start. Those models show, and decades of data confirms, that sexual selection can drive the evolution of outlandishly flashy and expensive traits like the tail of the Lyrebird.

It’s entertaining to think that economic growth and innovation might owe just as much to showing off as it does to the earnest attempts of consumers to obtain the bare necessities of life.

What is the most bizarre product you’ve ever encountered, and could it be a signal? Comment below or tweet @Brooks_Rob #mostbizarreproduct