Sex and Shopping


Gad Saad, a behavioral scientist and professor of marketing at Quebec's John Molson School of Business, has made his name exploring the links between consumer desire and biology. His most recent book is The Consuming Instinct: What Juicy Burgers, Ferraris, Pornography, and Gift Giving Reveal About Human Nature (Prometheus Books). Saad also holds the Concordia University Research Chair in Evolutionary Behavioral Sciences and Darwinian Consumption. In November producer Zach Weissmueller sat down with Saad to discuss sex, sales, signaling, and the biological roots of consumer decisions. Go to for the full interview. 

Q: What does evolutionary psychology have to say about what we spend our money on? 

A: There are myriad consumer phenomena that happen in exactly the same way around the world, so they transcend culture, they transcend time period, and they do that precisely because they are a part of a common biological heritage. What I try to do is look for these universals in the consumer arena and then argue that they are rooted in our shared biological heritage.

Q: Ferraris, pornography, juicy burgers, and gift giving. What is the significance of the list in your book's title?

A: I'm trying to demonstrate that there are four key Darwinian modules or metadrives that drive much of our consumer patterns. When it comes to juicy burgers, this refers to the survival module. Most animals have to face two recurring problems: making sure they don't become somebody's dinner and making sure that they find dinner. Our evolved gustatory preferences are an adaptation to that. It's not difficult for us to succumb to temptation, the Burger King and the McDonald's, because they are offering products that are fully congruent with our taste buds. When it comes to pornography or Ferraris, that refers to the mating module. I argue that the Ferrari is exactly the same in the human context as, say, the peacock's tail is to the peacock. The peacock shows his tail, and the females will choose that male who has the most iridescent colors, the biggest tail, the most symmetric patterns. The Ferrari is effectively signaling similar things, but in the human context. 

We did a study a few years ago with one of my former graduate students where we brought people into the lab—men—and we had them either drive a fancy Porsche or a beaten-up old sedan. At the end of each of these driving conditions, we would collect salivary assays to measure their fluctuating levels of testosterone. As you might expect, if you put a young male in a Porsche, his testosterone shoots through the roof. That endocrinological mechanism is akin to saying, "Hey, I was just imbued with a social win." We know that in many social species, when two males fight, the winner has a rise in testosterone and the loser has a drop in testosterone. 

Q: What's an example of that among women?

A: I did a study recently with one of my doctoral students where we tracked for 35 contiguous days—the full menstrual cycle—every imaginable consummatory behavior a woman engages in across those 35 days. Women engage in a lot more food-related behaviors in the luteal stage, the nonfertile stage of their menstrual cycle. In the fertile stage of their menstrual cycle, they engage in a lot more beautification-related things. They're engaging in sexual signaling. How provocatively they dress, whether they wear high heels, how they wear their hair, how much skin they show ends up being perfectly correlated to whether or not they are in the fertile phase. So there are two examples—testosterone in one case and the menstrual cycle in one case—that demonstrate how our hormones affect our behaviors as consumers.