In celebrities we trust, in gossip we act on instinct

Celebrity sells. We all know that: it’s one of the oldest clichés in the advertising handbook. But why? And why do some celebrities apparently sell more effectively than others?

On April 5, the advertising agency trade body the Institute of Practitioners in Advertising (IPA) is holding a half-day seminar on the subject. It’ll cost &£100 plus VAT to attend, but delegates will get a free copy of a new book, Celebrity Sells, by IPA director-general Hamish Pringle. Who says advertising agencies don’t understand sales promotion?

According to newspaper reports, Pringle believes the most successful celebrity ever to have appeared in a British advertising campaign is Prunella Scales, whose ads for Tesco have helped generate an additional &£2.2bn in sales since 1998.

Of course, the success or otherwise of an advertising campaign is dictated by more than the shrewdness of the casting. The copywriting, the media planning, the weight of spend, the aptness with which the ads reflect the existing strategy for a brand are all significant factors. Eliminating all the other variables and isolating the effects of a well-known name and face is not easy.

Nonetheless, if we all agree that celebrity does sell, one question immediately presents itself. Why? And a second question follows. If we can work out why it sells, can we bottle it?

And here another expert thinks he may have the answer. David Graham has been crunching numbers and consulting strategically in the television industry for about 15 years. He’s an expert in the analysis of television audience data, on the impact of broadcasting regulation and on the dynamics of the TV business.

He thinks a partial answer to the puzzle of why celebrities sell – and also to why some TV programmes work better than others – may lie in the discipline of evolutionary psychology and the associated fields of neuroscience and genetics. According to Graham, academic evolutionary psychologists believe we may be genetically programmed to behave in certain ways – a belief they have come to partly by observing that certain parts of the brain are always associated with certain skills or behaviours.

There may, for instance, be what Graham calls a “gossip instinct”. It was a useful thing to have 200,000 years ago, when mankind lived in foraging bands of 150 or so and the modern human brain evolved. To be successful in such a band required a complex mix of co-operation and competition. It helped to know quite a bit about your fellow band members, especially those of high status in the pecking order. So successful humans are those who are curious about friends, relatives, colleagues and anyone perceived to have high status – including, in the modern world, “stars”.

This helps to explain why we pay extra attention to someone we recognise as a star in a TV ad or on a poster – even though, rationally, we would be better off paying attention to an expert. A financial adviser or insurance broker is likely to know more about insurance policies than film director Michael Winner. But Winner is a celebrity, he draws our attention, and Esure will pay him a lot more than they would a financial expert to feature in its advertising.

What intrigues Graham is the possibility of finding practical applications for this kind of theoretical work that go beyond the simple observation that celebrities attract attention. He proposes, if he can find partners or clients willing to bankroll a study, to start with soap operas, looking at those moments which produced the highest audiences (and which BARB ratings show hold audiences for the longest periods) and seeing what elements they have in common and whether they connect up with the theory of evolutionary psychology. But in due course the same theoretical framework could obviously be applied to advertising as well.

Graham rejects the suggestion that he’s just trying to quantify the unquantifiable, or that a possible consequence of this work would be programmes and advertisements that were boringly similar. “The comforting thing is that people do have an appetite for variety,” he says. “That speaks against formulaic solutions and repeating oneself.”

But there is one potentially awkward implication in all this. It might strengthen the hand of those who maintain that entertainment and soap operas are “fast food for the brain”, and that our taste for them may be harmful. The analogy here is with our taste for sweet and fattening foods. That developed when we were hunter-gatherers, and fruits and fats were in short supply: we have been programmed to stuff ourselves with sugars and fats whenever we find them.

Our circumstances have changed, but our genetic make-up hasn’t. Obesity is the result. Perhaps our gossip gene, which also evolved in circumstances rather different from modern society, may be equally damaging.

Nick Higham presents Factfile on BBC News 24