Behaviour Change

PROPAGANDA FOR CHANGE is a project created by the students of Behaviour Change (ps359) and Professor Thomas Hills @thomhills at the Psychology Department of the University of Warwick. This work was supported by funding from Warwick's Institute for Advanced Teaching and Learning.

Friday, February 5, 2016

Quality over Quantity - An Alternative Use of the 'That's-Not-All' Technique

In the above advertisement for Oral B toothpaste, A dentist appears onscreen and makes the extraordinary claim that 1 in 2 people suffer from gum problems (this would be 32 million people in the UK alone). The dentist explains how plaque can lead to such gum problems and then goes on to explain how Oral B toothpaste (the product being advertised) can tackle this. Shortly after, the dentist then tells the audience how the toothpaste also benefits several other areas of oral hygiene, with a list of these areas appearing onscreen soon after.

While the presence of a dentist (a perceived expert on oral hygiene) means that the principle of source credibility is obviously applicable here, the advert also uses a slightly nuanced version of the ‘that’s-not-all’ (TNA) technique. Rather than employing the oft-used ‘two for the price of one/buy one get one free’ method, the emphasis here is on product quality rather than quantity. Specifically, the dentist outlines the main selling point of the product (that it can prevent plaque and thus reduce the risk of gum problems) and then goes on to explain how the product can benefit the user in several other ways. By following up the main selling point with an additional list of other ones, the advert attempts to get the audience to think, “So this toothpaste can stop me from getting gum disease, but hold on, wait, it also does all these other things as well! I’d be getting so much value for my money if I went with this toothpaste.” Thus, the advert applies the TNA technique to the features of the product to increase the viewers’ perceptions of the product’s worth in an attempt to induce compliance.

Figure 1: A bar chart comparing the percentage buying rate in the TNA condition with the control condition.

In a well-known study, Burger (1986) investigated the influence of the TNA technique on compliance. The setting of a psychology bake sale was used to investigate this persuasive technique. In the experimental condition, subjects who inquired about the price of a cup cake were told to “wait a second”, and a brief exchange between the first seller and the second seller briefly ensued. Shortly after, the seller then produced two cookies and told the customer that they were included with the price of the cupcake. In the control condition, the potential buyer was informed of the two additional cookies as soon as they were told of the price. (In a similar vein, the advert above features an initial selling point which is then followed up with additional different selling points, rather than presenting all aspects of the product simultaneously.) As illustrated in the graph above, it was found that more subjects purchased products in the experimental condition (73% buying rate) than in the control condition (40% buying rate), demonstrating the increased compliance induced by the TNA technique.

Liam Ward


Burger, J. M. (1986). Increasing compliance by improving the deal: The that's-not-all technique. Journalist of Personality and Social Psychology, 51(2), 277.

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