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.

Monday, February 29, 2016

Green Tea Can Make You Smarter!

This poster provides an example of celebrity endorsement on products because it includes many high-profile celebrities and powerful figures which people would recognise drinking the product that is being advertised, i.e. Green tea. 

Research conducted by Atkin and Block (1983) compared the effects of celebrity endorsers and non-celebrity endorsers. 196 participants, aged 13-77 years old were shown an advertisement and rated the advertisement using an 18-item questionnaire. The advertisement consisted of different celebrity and non-celebrity endorsers. 

They found that for all age groups, celebrity figures were rated as more competent and trustworthy and the product was more favourable. This was more effective on teenagers compared with older participants.

The table shows the mean scores for the two conditions. This shows that participants mostly favoured the celebrity-endorsed advertisement. It also shows they found the character more trustworthy, attractive and competent. They preferred the image with the celebrity and thought it was more effective. Hence, by using celebrities in my own advertisement, people will more likely favour the product and will find it more effective if a non-celebrity model was used to demonstrate the benefits of green tea.

Also, the use of attractive celebrities (mainly David Beckham, Channing Tatum and Rhianna, however, you can argue David Cameron and Prince Charles are sexy in their own kind of way) can persuade viewers more. Chaiken (1979) compared attractive and unattractive communicators by asking them to deliver a persuasive message to participants. They found that attractive communicators were more persuasive than non-attractive communicators and there was greater agreement with the attractive communicators. Chaiken suggested this was because attractive communicators possessed a characteristic that disposed them to be more effective communicators. So, by using attractive celebrities in my advertisement, it can be argued they will be more persuasive to viewers. 

Atkin, C., & Block, M. (1983). Effectiveness of celebrity endorsers. Journal of Advertising Research, 23, 57-61.

Chaiken, S. (1979). Communicator physical attractiveness and persuasion. Journal of Personality & Social Psychology, 37, 1387-1389.

Support Local Farmers and Eat Wonky Veg!

This advert has been created to promote the fact that wonky veg is losing our farmers £1000s each per year and that we should purchase misshapen produce to keep British farmers in business. This advert is based on the central processing route of the Elaboration Likelihood Model (Petty, Cacioppo, and Schumann, 1983). This central route involves a higher level of cognitive processing where the individual pays attention to the messages being conveyed with the aim to result in a lasting attitude change.

The first persuasion technique used in this advert is the concept of the communicator. In this instance one of the messengers is a professor at a credible educational institute, a university, therefore their professors would understand the financial impacts on such industries. Holland & Weiss (1951), emphasised through research that the credibility of the source is an important factor in persuasion and more people are likely to obey the source’s message when they are seen as trustworthy and to hold expertise in the subject.

Although only a national (rather than global) celebrity, Hugh Fearnley-Whittingstall is a UK chef and  a passionate campaigner on food and environmental issues; therefore he can again be seen as an expert on this issue. Aktin and Block (1983) investigated the impact of celebrity endorsement on consumers and found that adverts with a celebrity were rated significantly more trustworthy and competent compared to adverts with individuals who weren’t celebrities. So using a celebrity can increase the likelihood of compliance. 

Also because he is a British chef and this advert is campaigning to help British farmers, the audience may already feel part of an in-group (being from Britain) thus more likely to conform and buy misshapen vegetables (Mackie, Gastardo-conaco & Skelly, 1992). This is consistent with the self categorisation theory whereby individuals will categorise themselves as part of a group and will then share the views and do similar things to that in-group (Turner et al,1994). 

Another persuasion technique is to do with the statement ‘1000s of people are supporting our local British farmers, are you one of them?’. Here is an example of social norms. Individuals tend to do what others around them are doing and are thus influenced by behavioural expectations or rules to the society that they belong to (Shaffer, 1983). Thus stating ‘1000s’ people are already doing it makes it more normal to then go and buy these cheaper, misshapen vegetables. Furthermore if people are unsure whether purchasing misshapen veg is safe, then having the knowledge that 1000s of people are already purchasing this produce makes people feel safe enough to then conform to those ideas  through the theory of social comparison (Festinger, 1954). 


Atkin, C. and Block, M. (1983). Effectiveness of celebrity endorsers. Journal of Advertising Research, 23, 57-61. 

Shaffer, L. S. (1983), "Toward Pepitone’s Vision of a Normative Social Psychology: What Is
a Social Norm?," Journal of Mind and Behaviour, 4 (2), 275-93.

Festinger, L. (1954). "A theory of social comparison processes". Human relations, 7, (2), 117–140.

Hanson, L. (2015). Come on supermarkets – wonky is the shape of fruit and veg to come. Retrieved 29 February, 2016, from

Hovland, C. I., & Weiss, W. (1951). The influence of source credibility on communication effectiveness. Public Opinion Quarterly, 15, 635-650.

Mackie, D, Gastardo-Conaco, M & Skelly, J. (1992). Knowledge of the Advocated Position and the Processing of In-Group and Out-Group Persuasive Messages. Personality and Social Psychology Bulletin, 18 (2), 145-151.

Petty, R. E, Cacioppo, J. T., & Schumann, D. (1983), Central and Peripheral Routes to Advertising Effectiveness: The Moderating Role of Involvement. Journal of Consumer Research, 10, 135-146.

Turner, J. C., Oakes, P. J., Haslam, S. A. & McGarty, C. A. (1994). Self and collective:  Cognition and social context. Personality and Social Psychology Bulletin, 20, 454-463.  

Vaughan, A. (2015). Hugh Fearnley-Whittingstall rejects Morrisons' 'pathetic' wonky veg trial. Retrieved 29 February, 2016, from hugh-fearnley-whittingstall-rejects-morissons-pathetic-wonky-veg-trial

Willmot, R. (2016). Bangor University. Retrieved 29 February, 2016, from https://

Get Katy Perry's California curves with the M-Plan diet!

This advert encourages people to replace one meal and a snack a day with a mushroom based meal for at least two weeks. The idea is that eating mushrooms daily will help avoid snacking during the day as they are high in dietary fibre and help you to feel fuller for longer, as well as assisting weight loss, particularly around the thigh area, as they are low calorie and low in fat but high in protein and healthy carbohydrates, without reducing bust size. This advert uses Katy Perry's endorsement, as she claims that the M-Diet is the secret to her hourglass figure.

Katy Perry's celebrity endorsement is a particularly useful persuasive technique due to the congruence model of endorser effects, which requires congruity between the endorser and consumer. In this case, Katy Perry's figure and the benefits promoted by the M-Plan diet are congruent with the ideal self of consumer, as this body shape is widely perceived to be attractive. As a result, there is congruence between the celebrity endorser, Katy Perry, and the diet consumer's ideal self which enhances the advert's persuasiveness (Choi & Rifon, 2012).

Furthermore, Chan, Ng, and Luk's (2013) research found that celebrity endorsement in advertisements is best recalled when the celebrity is perceived as being attractive, and that this type of celebrity endorsement enhances consumer's confidence in the success of the product. For this reason, Katy Perry, who is generally considered to be an attractive pop-star, works well in endorsing the M-Plan diet and provides the consumer with confidence that the diet will work for them too.

In addition, Katy Perry provides a good example of the body type which the M-Plan diet claims to achieve. This utilises techniques of visual persuasion, as Messaris (1997) highlights that consumers automatically assume a link between pictures and reality within adverts, thus consumers viewing this advert will automatically link the M-Plan diet to the body shape they wish to achieve, enhancing the advert's effectiveness in persuading consumers to try the diet for themselves.


Chan, K., Ng, Y. L., & Luk, E. K. (2013). Impact of celebrity endorsement in advertising on brand image among chinese adolescents. Young Consumers,14(2), 167-179.

Choi, S. M., & Rifon, N. J. (2012). It is a match: The impact of congruence between celebrity image and consumer ideal self on endorsement effectiveness. Psychology & Marketing, 29(9), 639-650. 

Messaris, P. (1997). Visual persuasion: The role of images in advertising Sage Publications, Inc, Thousand Oaks, CA.

Ginger: A Super Spice!

This ad aims to convince people of the multiple benefits of ginger, and potentially convince them to include more of it in their diets. It uses of a few persuasive techniques in order to make people more responsive to it. 

Firstly, the play on the font makes specific words stand out more and therefore captures the readers’ attention (Wolfe & Horowitz, 2004). They highlight all the benefits (health related and others) that ginger can provide and give the sources of the arguments (such as the Guardian), leading people to focus more on that and realise the benefits of this spice. 

Listing all the benefits is another way of persuasion. Making information available to the observer, as well as its sources, will increase the observer’s knowledge about the benefits of that spice, as well as enhance his or her trust towards it because of the information quality, coming from known and reliable sources, (Charles & O’Reilly, 1982). Indeed, the perceived expertise of the sources enhances persuasion power. The more credible the sources are, the more accepted the information will be, and a positive correlation will be formed, linking the information to favourable outcomes (Cook, 1969). 

Another persuasive technique used in this ad, is the addition of the non-health benefit of ginger being an aphrodisiac. When reading the sentence “And on top of being a super spice with amazing health benefits, ginger is also known to have aphrodisiacs powers . . . .”, the readers may see a more light-hearted side to the article and will be left in a good mood with a smile on their face. Geuens & De Pelsmacker (2002) conducted a study about the role of humour in persuasion. They presented participants with humorous adverts and less humorous ones, and recorded their responsiveness to them by giving them scales about their feelings, such as pleasant/unpleasant, likable/unlikable, favourable/unfavourable, persuasive/unpersuasive etc. Results show that the use of humour in general had a positive impact on affective responses, and a significant positive effect on the attitude towards the ad and the brand. Therefore, the addition of this little sentence in the advert will increase the likability people will have towards it, make it more powerful, and better promote ginger in general.


Charles, A., & O’Reilly I. (1982). Variations in Decision Makers’ Use of Information Sources: The Impact of Quality and Accessibility of Information. Acad Manage (25)4, 756-771

Cook, T. (1969). Competence, counter arguing, and attitude change. Journal of Personality, 37, 342-58.

Geuens, M, & De Pelsmacker, P. (2002). The Role of Humor in the Persuasion of Individuals Varying in Need for Cognition. Advances in Consumer Research, (29)1, 50-56
Wolfe, J. M., & Horowitz, T. S. (2004). What attributes guide the deployment of visual attention and how do they do it? Nature Reviews Neuroscience, 5, 495-501. 

Eat Your Greens!


Many of you will probably remember being told to "eat your greens" as a child by your parents. However, the media reports that numerous people are not meeting their recommended 5-a-day.

This advert makes use of a few persuasive techniques, including message repetition. According to Zajonc (1968), mere repeated exposure to a message can enhance an individual's attitude towards it, as it appears more believable to them, so they are more accepting of it. Furthermore, Cacioppo and Petty (1979) found 3 to be the optimal number of times to expose a repeated message; any more or any less than this decreased agreeability. Due to these findings, the ad makes use of just 3 repetitive messages:
  • "Eat your greens!"
  • "8 Super Green Foods"
  • "Do you get enough green?"

Automatic activation is another form of persuasion used in the advert. Reading a message with arguments in favour of the focal attitude object ought to increase favourability of other objects related to the focal one (Horcajo, Brinol & Petty, 2010). In this case, the use of the word 'green', and its matching colour scheme, should promote purchase/consumption of fruit and vegetables.

By adding an image of a doctor in the advert, it infers an authorative figure role. This has previously been shown in the well-known study by Milgram (1963), in which participants' continued to obey the orders given by an experimeter wearing a lab coat. Perceived authority thus means a higher rate of agreeability, so the ad makes use of this persuasive technique. As well as this, viewers should see the figure as a credible source and believe the information more readily (Pornpitakpan, 2004)

A final persuasive technique incorporated by this advert is the use of a rhetorical question: "Do you get enough green?". As reported by Petty and Cacioppo (1981), if the message is of low personal relevance to the individual, then they are not naturally processing the statement. Because of this, it enhances their thinking by presenting a new concept to them, especially if there is a strong argument to back it up. In light of this, the ad follows up the question with a few facts on health benefits of eating fruit and vegetables.


Cacioppo, J. T., & Petty, R. E. (1979). Effects of message repetition and position on cognitive response, recall,and persusaion. Journal of Personality and Social Psychology, 37, 97-109.

Horcajo, J., Brinol, P., & Petty, R. E. (2010). Consumer persuasion: Indirect change and implicit balance. Psychology & Marketing, 27, 938-963.

Milgram, S. (1963). Behavioral Study of Obedience. The Journal of Abnormal and Social Psychology, 67, 371-378.

Petty, R. E., & Cacioppo, J. T. (1981). Effects of rhetorical questions on persuasion: A cognitive response analysis. Journal of Personality and Social Psychology, 40, 432-440.

Pornpitakpan, C. (2004). The persuasiveness of source credibility: A critical review of five decades' evidence. Journal of Applied Social Psychology, 34, 243-281.

Zajonc, R. B. (1968). Attitudinal effects of mere exposure. Journal of Personality and Social Psychology, 9, 1-27.
The tiny berry with big benefits

Acai berries have recently been touted as the new and trendy superfood with anti-ageing and weight loss properties. The advertisement I created utilised multiple technique to convince people to purchase and eat acai berries including a rhetorical question, scarcity, just plain folks and the but that’s not all technique. 

Firstly, the advertisement starts with a rhetorical question “do you want to know the secret to weight loss?” this immediately captures the readers attention as many people in society have a desire to lose weight. Bunkrant and Howard (1984) found that rhetorical questions may have benefits in advertisement as they not only arouse uncertainty, but encourage more intensive processing of the message. Furthermore, Zillman (1972) demonstrated the effectiveness of rhetoric elicitation by using a mock court trial. Undergraduates were presented with persuasive information about the criminal who was up for trial. Following this, they were presented with a conclusive message as either a statement or rhetoric question. The influence of the persuasive message was measured by the length of time the student believe the prisoner should serve in jail. Those presented with the rhetorical question gave shorter prison sentences, suggesting a rhetorical question provides a more effective persuasive message.

Secondly, the advertisement employs the just plains folks technique (Pratkanis, 2007) by showing a before and after picture. By using a normal, average looking women to take a before and after photo and attributing the dramatic weight loss to the acai berries 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 being similar to them they will be more inclined to view the berries in a positive light and consequently purchase them. The evidence for this technique comes from a field experiment conducted by Brock (1965). In his experiment he asked salesmen to encourage shoppers to buy paint vastly different in price to their original choice. Salesmen did this by either portraying similarity or dissimilarity with the customer, specifically with respects 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 and the dependent variable was the level of compliance shown by the customers. 

The table shows this was particularly successful. When there was perceived similarity between the salesman and the customer there was 11% more compliance than in the dissimilar condition. Essentially, people can be induced to but more expensive paint due to similarity in something as trivial as paint. This suggests that consumers will believe that if acai berries work for her, they can work for me.                 

Thirdly, by stating on the advertisement that you should “act now while supplies lasts” is utilising the scarcity principle to enhance sales of the product, and to persuade people to give it a go. The scarcity principle suggest that products such as acai berries are more valuable when they are less available. This adds value to a product, by reducing the availability of it. As argued by Cialdini (2009) this challenges people emotionally and cognitively where they feel they are loosing freedom. so are more likely to purchase it. The item is likely to be good due to how rare it is. An experiment by Worchel, Lee and Adewole (1975) confirms this. They asked participants to rate how attractive and valuable cookies were, depending on abundance and scarcity. Participants gave higher ratings to cookies when they were presented to them to be scare rather than abundant. Furthermore, they were rated as more expensive in the scare condition, suggesting they were more valuable. Therefore, this experiment provides evidence that the scarcity principle really works where items are seen as more attractive when their availability is threatened.

Finally, the advert highlights the other health benefits of taking acai which utilises the “that’s not all technique” which aims to convince the reader that they are receiving a multitude of benefits from the product in addition to weight loss. This consequently was included to make people believe they are getting a lot for their money. This technique has been found to increases sales of items dramatically, as displayed by the experiment by Burger (1986). In his study, he conducted a bake sale where participants were offered a cupcake and cookies for 75 cents or offered a cupcake for 75 cents plus the addition of cookies at no extra charge (the TNA condition). He found those in the TNA condition were significantly more likely to buy the cupcakes (73%) than those who were offered cup cakes and cookies in one bundle (40%). Burger’s finding suggests people are more likely to buy products when they are accompanied by TNA persuasion techniques because they feel they are getting more for their money.

Brock, T. C. (1965). Communicator-recipient similarity and decision change. Journal of Personality and Social Psychology, 1, 650-654

Burger, J. M. (1986). Increasing compliance by improving the deal: The that’s-not-all technique. Journal of Personality and Social Psychology, 51, 277-283.

Burnkrant, R. E., & Howard, D. J. (1984). Effects of the use of introductory rhetorical questions versus statements on information processing. Journal of Personality and Social Psychology, 47,1218- 1230. 

Cialdini, R.B. (2009). Influence: science and practice. Boston : Allyn and Bacon

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.

Worchel, S., Lee, J., & Adewole, A. (1975). Effects of supply and demand on ratings of object value. Journal of Personality and Social Psychology, 32(5), 906-914.

Zillmann, D. (1972). Rhetorical elicitation of agreement in persuasion. Journal of Personality and Social Psychology, 21(2), 159.

Sunday, February 28, 2016

Ditch Dairy.

The above advertisement is aimed at getting people to give up dairy foods by highlighting the various benefits to the environment and their health. The ad also warns of the dangers of dairy consumption.

A variety of persuasive techniques were integrated for maximum effect. Ariana Grande is a crucial part of this ad – being an attractive young woman who people desire to be, she is a key device for persuasion. Celebrity endorsement is a tactic often used in advertising whereby the message of the ad is associated with the attractiveness and popularity of the celebrity, making the target audience more likely to endorse the message (Erdogan, 1999). Further, the ad highlights the benefits Ariana has seen after eliminating dairy from her diet, such as weight loss. Associating the message with such positive rewards will further encourage people to change.

Another tactic used is the ‘door-in-the-face’ technique. This is where an extreme request is rejected and then followed by a moderate request. In the ad, this is used by first suggesting that people should save the lives of cows by cutting out beef (an extreme request), then following this with a smaller request to save cows by cutting out dairy instead. This works because of the norms of reciprocation, where due to the apparent concession being made by reducing the request to a smaller offer, the target is therefore more likely to comply with this smaller request (Cialdini and Ascani, 1976). For example in a study by Cialdini, Vincent, Lewis, Catalan, Wheeler and Darby (1975), subjects were first asked to be a counselor for two hours a week for two years (the extreme request), then after this was rejected they were asked a smaller request to make one two-hour commitment. Thanks to norms of reciprocation, this technique yielded a higher compliance rate compared to control conditions.

But wait... That’s not all! This ad uses the ‘that’s-not-all’ technique by presenting a wide range of the benefits of cutting out dairy, and then stating that there are even more benefits on top of those already mentioned. This makes the idea of cutting out dairy look even better than it did before. Burger (1986) demonstrated this by improving a cupcake deal (one 75p cupcake or one cupcake and two cookies for 75p), which increased compliance and doubled sales.

Additionally, the use of expert testimony from the University Professor in this ad enhances the credibility and trustworthiness of the information, making it more effective at persuading people to change their behaviour. Many studies have shown the influence of source credibility, for example, people who read an article were more likely to believe it when the author was a scientist (and thus a credible source) compared to a non-credible source, which in this case was a Soviet news agency named PRAVDA (Hovland & Weiss, 1951).

Finally, the technique of repetition was used with the simple message to ‘Ditch Dairy’. Repeating a message increases the liking for it, and this rise in familiarity leads us to infer that the opinion is popular, thus repetition acts as a form of social proof. Weaver et al., (2007) demonstrated this by showing that one message repeated three times was equally as persuasive as one message heard from three different people.


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

Cialdini, R. B., & Ascani, K. (1976). Test of a concession procedure for inducing verbal, behavioral, and further compliance with a request to give blood. Journal of Applied Psychology, 61(3), 295.

Cialdini, R. B., Vincent, J. E., Lewis, S. K., Catalan, J., Wheeler, D., & Darby, B. L. (1975). Reciprocal concessions procedure for inducing compliance: The door-in-the-face technique. Journal of personality and Social Psychology, 31(2), 206.

Erdogan, B. Z. (1999). Celebrity endorsement: A literature review. Journal of marketing management, 15(4), 291-314.

Hovland, C. I. & Weiss, W. (1951). The influence of source credibility on communication effectiveness. Public Opinion Quarterly, 15, 635-650.

Weaver, K., Garcia, S. M., Schwarz, N., & Miller, D. T. (2007). Inferring the popularity of an opinion from its familiarity: a repetitive voice can sound like a chorus. Journal of personality and social psychology, 92(5), 821.

3 litres of water a day will keep the doctor away

This advertisement has utilised many persuasive techniques in order to convince people to drink more water.

Firstly, the advert has made use of expertise endorsement, through the use of ‘medical experts at the Institute of Medicine’, a highly reputable organisation. Experimental investigations into the persuasive effect of source credibility have demonstrated that people are more susceptible to persuasion when the source is highly trustworthy and seen to be an expert (Bickman, 1974; Hovland & Weiss, 1951).

Secondly, this advert aims to elicit an emotional response from the observer, through the phrase ‘not drinking enough water will make you sick, ugly and fat!’ Becheur, Dib, Merunka and Valette-Florence (2008) found that advertisements that caused emotional responses were effective in persuading people to change their behaviour. Hovland, Janis and Kelley (1953) proposed that the use of fear would increase the likelihood of persuasion, as compliance to the message reduces emotional tension. The fear that not drinking enough water will make the person fat, ugly and sick may induce this reaction, which will result in them changing their behaviour.

            Finally, this advertisement informs the observer of both the benefits of drinking water and the side effects of not drinking enough water. As the observer is made to consider the consequences of both situations, the receiver is undergoing central processing according to Petty, Cacioppo and Schumann (1983). The central route to persuasion results in the observer taking part in thoughtful consideration of the arguments and, as the advertisement also involves a credible expert, this will engage the viewer and will be very influential in changing their behaviour.

Bickman, L. (1974). The social power of a uniform. Journal of Applied Social Psychology, 4(1), 47-61.
Becheur, I., Dib, H., Merunka, D., & Valette-Florence, P. (2008). Emotions of fear, guilt or shame in anti-alcohol messages: Measuring direct effects on persuasion and the moderating role of sensation seeking. European Advances in Consumer Research, 8, 99-105.
Hovland, C. I., Janis, I. L., & Kelley, J. J. (1953). Communication and Persuasion. New Haven, CT: Yale University Press.
Hovland, C. I., & Weiss, W. (1951). The influence of source credibility on communication effectiveness. Public Opinion Quarterly, 15, 635-650.
Petty, R. E., Cacioppo, J. T., & Schumann, D. (1983). Central and peripheral routes to advertising effectiveness: The moderating role of involvement. Journal of Consumer Research, 135-146.