Rory Sutherland On Advertising: Brands are like the antlers on a stag

(Kitcatt Nohr Alexander Shaw)

When my twin daughters were about three, I dreamed about how much easier life would become once they developed the power of conscious, rational thought. Life would be so much more pleasant, I imagined, once you could simply explain to them not to run onto the road rather than having to attach harnesses to them.

I couldn't have been more wrong. What I didn't realise is that, mere seconds after they had grasped the concept of rational argument, they would also master the concept of arguing back. Suddenly it was like living with a couple of tiny George Carmans. "Why did you buy that hat?" "Why did we have to buy a black car?"

What makes this endless cross-examination of your life so mentally exhausting is that we really have no conscious, rational explanation for most of what we do. Articulating why we like a particular toothpaste, or want to holiday in France, is difficult without resorting to sentences such as "Look, I just feel like it, alright? Now go watch Hannah Montana."In the book Strangers to Ourselves, Dr Timothy D Wilson compares the role of the conscious mind in human decision-making to a child playing an arcade game without having put any money into the machine. While the Space Invaders cycle through a preordained game in "demo" mode, the child excitedly wiggles the lever while somehow managing to maintain the illusion that his hand actions are driving events on screen. Man, many scientists now believe, may not really be a rational animal but a post-rationalising animal; the conscious brain merely passing commentary on the actions of the unconscious in the way that football commentators contrive a narrative to explain the largely random events taking place on the field.

New work in behavioural economics and neuroscience poses an interesting challenge to the advertising and research industries, both of which go about their daily work under the supposition that it's the conscious brain that's doing the shopping. Attempts are still made to understand consumer behaviour in the light of what people say – even though, in many cases, people can no more explain their actions than a cricketer can explain the physics behind catching a ball. And advertising still works to an overt proposition, as though people were principally driven by persuasion rather than seduction.

A brand new book, Spent, by the Darwinian psychologist Geoffrey Miller is interesting, since it seeks to explain consumer behaviour in terms of signalling: the idea being that people instinctively buy brands to signal a few basic human characteristics which are desirable in a mate – brands serving a similar function to antlers on a stag. The six psychological variables we instinctively want to signal (Intelligence, Conscientiousness, Openness, Agreeableness, Extraversion and Stability) are supposedly not only common to all humans of all cultures but are also shared by all higher primates, and many mammals including dogs, cats, horses and – no, I wasn't expecting this either – hedgehogs.

Spent is only one of many explanations of how advertising works. Much communication may work at an even more naive level – we like to buy products from people we like, and we like meercats, so that means they must be nice. Compare the Market's approach is quite unusual in the Anglo-Saxon world as it attempts little more than likeability. In other parts of the world, such as Japan, this approach would be routine. Other marketing disciplines, such as design, work almost entirely at the level of the subconscious.

A broadening understanding of these different models is now more important than ever, since "advertising", once dominated by one or two media, now takes so many more forms. Increasingly, brands are judged more on the experiences they deliver than by the promises they make. An iPhone app can now be as much an advertisement as a TV commercial.

Rory Sutherland is vice-chairman of Ogilvy Group

Best in Show: Waitrose (Kitcatt Nohr Alexander Shaw)

There is still a large role for rational advertising: for instance, as a "nudge" or a reminder of sensible things people can do which they may not think of doing unprompted.

This direct mail campaign to Waitrose's Delivery Customers is a good example of this: if you are holidaying in the UK, this explains that Waitrose can deliver to your holiday cottage just as to your home, leaving you free to spend your time on the beach not at the shops. It is the kind of helpful, thoughtful and timely direct mail I'd like to receive more of.