Many of you may have already heard of a craze not so long ago for 'Teatox' - a special blend of herbs that, when brewed, could magically make you skinnier. No exercise, no dieting, no change to your daily activities... but to drink tea three times a day. Losing weight this way seems not just impossible, but ridiculous, yet I know girls who are slowly sipping their way to poverty. So how have these companies duped so many of us into forking out 50 times what we would normally spend on tea? They employ the 'Just Plain Folks' technique (Pratkanis, 2007). Like the photo above, companies get normal, average looking women to take photos of themselves before and after they've 'lost weight' drinking only their miracle-tea. Using relatable women in their campaigns demonstrates source-recipient similarity which in turn increases compliance. Festinger (1954) says this is due to the social comparison process: people have a tendency to turn to similar others as referents for their opinions on specific issues. Hence, if potential customers see the campaign girls as being 'one of us', they will be more inclined to think of the tea in a positive light, and more likely to part with their cash.
The evidence for this technique comes from a field experiment conducted by Brock (1965). In his experiment he asked salesmen to try to encourage shoppers to buy paint that was different in price (higher or lower) to their original choice. Salesmen did this by either portraying similarity or dissimilarity with the customer, specifically with respect to the salesman's prior magnitude of paint consumption. Thus the independent variables were the salesman's similarity to the customer and the direction of change in price level. The dependent variable was the level of compliance of the customers.
As the above table shows, they were very successful. When there was a perceived similarity between the salesman and the customer there was 11% more compliance than in the dissimilar condition. Essentially, people can be induced to buy not just cheaper paint, but more expensive paint due to a similarity in something as trivial as prior paint consumption. If so, it is more than possible that girls will use the average Jane up on the wall as a referent and think "If it works on her; it works on me", however daft the concept!
Brock, T. C. (1965). Communicator-recipient similarity and decision change. Journal of Personality and Social Psychology, 1, 650-654.
Festinger, L. (1954). A theory of social comparison processes. Human Relations, 7, 117-140.
Pratkanis, A. R. (2007). Social influence analysis: An index of tactics. The science of social influence: Advances and future progress, 17-82.