Wednesday, May 20, 2009

“Rational Man” Replaced by “Post-Rational Emotional Man”

I recently read a review, by Gloria McDonough-Taub at, of Geoffrey Miller’s book entitled “SPEND: Sex, Evolution and Consumer Behavior.” Professor Miller “reveals the unseen logic behind the chaos of consumerism . . .” and he argues that “Marketers still don’t understand human nature and that hurts business.”

In short, he argues like many others that the “Rational Man” Model from economics is too limited. This model says that consumers “maximize utility” by rationally comparing and buying products and services that give them the greatest “subjective utility,” i.e. pleasure or happiness.

Enter, “Conspicuous Consumption” (Thorstein Veblen, “The Theory of the Leisure Class”) which says that consumers often buy products that will impress others even if they don’t deliver personal happiness.

Professor Miller points out that this remains true but it must be supplemented by “genetically heritable traits” that can predict a wide range of behavior including consumption. Miller’s traits include intelligence, openness, consciousness, extraversion, agreeableness and emotional stability. Each trait falls upon a continuum.

I don’t know about you, but I like to think that I fall on the upper and positive end of each trait. His theory would suggest that I prefer a Lexus Hybrid to a Harley Hog, that I qualify for a low-interest loan, that I am a Green Consumer and that I am interested in new ideas and fashions.

This is probably a great improvement over Rational Man and Conspicuous Consumption but I don’t think that it accounts for a Post-Rational Emotional Man when faced with a specific purchasing decision. Although I agree that it is valuable to construct a psychological model for consumer behavior based upon the most recent findings by evolutionary psychologists, I think that the “context” surrounding the purchase remains important.

I prefer to pictographically duplicate a purchasing scenario for a type of product and then let the potential consumer explain their reactions to each step in the process. Pictographs are similar to story boards and enable the consumer to tell a story, without leading questions from the researcher. Objectively some consumer behavior doesn’t make sense, but subjectively it can be explained. For more information email


  1. I agree with you Dale. Context/environment is easily the most influential factor in determining behaviour, feelings and thoughts. You only have to look at how someone born in one region can have a totally different faith system than someone born a few miles away in a different country.

    Philip Graves
    Consumer Behaviour Researchauthor of "The Secret of Selling: How to Sell to Your Customer's Unconscious Mind"

  2. Philip,

    Thanks for your comment. It looks to me that we are in the same choir.