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, January 30, 2015

This Weekend Only!

Smoothies and frapp
es for one dollar sounds like a great deal. However these Burger King drinks are only offered for a limited time, only during a particular weekend. So, what to do? To not miss out on the bargain, this limited availability encourages people to purchase a drink. The perception of a deal as scarce leads to the perception of value, leading people to desire it more. In this case, smoothies and frappes for $1 may be seen as a rare occurrence, making it more appealing.

To further investigate the mechanism behind the effect of scarcity on consumer behaviour, Aggarwal, Jun, and Huh (2013) examined people’s intentions to purchase a product after viewing advertisements presenting products that were limited in quantity, as well as products limited in time availability. Consumer competition was proposed as a reason for the scarcity effect, suggesting that people are motivated to purchase “rare” items and in the near future, so that other people may not buy it before them, which would cause them to lose their chance. In the study, one hundred and twenty-one students were placed in one of three conditions: time limited, quantity limited or control. They viewed print advertisements with messages such as “First 100 customers only” and “For six days only”. The participants then rated their purchase intention on a seven-point scale. They also rated their feelings of consumer competition on a seven-point scale.

The study found that both time-limited (M = 5.35) and quantity-limited (M = 4.39) advertisements were effective in raising consumer intentions to purchase a product, compared to the control group (M = 3.83), as displayed by the purchase intention scores (
F (2, 120) = 16.48, p < .01). Limiting quantity appeared to be most effective. Furthermore, consumer competition appeared to be a significant mediator between scarcity and consumer intentions. In the regression analysis, the coefficient for scarcity message declined from .769 to .445 at the introduction of consumer competition, compared to a regression equation that only incorporated scarcity.

As a result, the use of a time limit by this Burger King advertisement would be an effective strategy to increase consumer spending during the advertised weekend. The company would do well to continue employing this tactic, due to consumer competition, at least in part. Despite this, focusing on advertisements that present items that are limited in quantity may do even better, as suggested by this study. For example, Burger King might advertise: “The first 50 people to purchase a burger will receive 30% off”. This may further increase sales on top of time-oriented messages.

Yida Liao

Aggarwal, P., Jun, S.Y., Huh, J.H. (2013). Scarcity messages.  Journal of Advertising, 40, 19-30.

How to get free beer.

In the recent past one of my housemates decided to go home for the weekend – leaving behind fifteen refreshing bottles of ice cold lager beer. Armed with a wealth of knowledge about persuasion, I grabbed my cellular device. The following text conversation reveals what happened next:

By using the door-in-the-face (DITF) technique I persuaded my housemate to let me have two of his beverages. The DITF technique involves making an unreasonable request that would usually be declined. This is followed by a second, more reasonable request. People are more likely to agree to the second request if it follows an unreasonable one, when compared to asking the second request alone.

Pascual and Gueguen (2006) provide a convincing demonstration of DITF in a field experiment. Participants were young adults who happened to be sitting alone at a bar in a French seaside resort. The participants were unaware that the male and female sat on the next table were confederates. After both ordering and drinking a lemonade, the male confederate leaves and proclaims (loudly enough for the participant to hear) that he is leaving to buy a part for his bicycle. Two minutes later the female confederate tries to leave, before being told by a staff member that the male confederate had not paid the bill. Participants were randomly allocated into one of two conditions.

In the door in the face condition, the female confederate approaches the participant and asks them to pay for the full cost of the drinks - as she had no money. No participant agreed to pay the full bill. Then the participant is asked to donate just “two or three francs to pay part of the bill”. 75% of subjects agreed to comply with the second request. In the control condition participants were only asked to comply with the second request. Then, only 10% of participants agreed to donate. 

The results are depicted in figure 1.

The DITF technique allowed me to persuade my housemate into giving me a couple of free beers. My intention was never to get the full crate. However, administering an unreasonable request first made the second request (of just two bottles) seem more than reasonable. As Pascual and Gueguen (2006) would predict, if I first asked for two free beers my housemate would probably say no.

Free beer... That's got to be the best psychological application ever, right?

Pascual, A., & Gueguen, N. (2006). Door-in-the-face technique and monetary solicitation: an evaluation in a field setting. Perceptual and motor skills, 103, 974-978.

But Wait, That's Not All!

Here is a story from my personal experience, which provides an interesting example of the “That's Not All” persuasion technique.

One day, I was doing my grocery shopping at the local Morrison's store in Leamington Spa, when suddenly an announcement caught my attention. It appeared that anyone who was willing to listen to a presentation on some fantastic new knife sold exclusively in Morrison's would get a free vegetable peeler worth £4.99 at the end. Well that was persuasive enough, who can say no to free stuff? So, off I went.

The presentation was almost a performance. The lady showed us all how this knife magically cut through a wooden chopping board, dented a piece of metal and cut effortlessly through a tomato, which she claimed would be easily squished by an ordinary knife. Needless to say, this super knife seemed rather impressive. However, the proposed price of £25 dampened mine and I'm sure a lot of other people's enthusiasm.

“But wait!” the lady said. “That's not all.”
After highlighting that the knife was sold exclusively at Morrison's (sneaky use of the “scarcity” technique I talked about in my first blog post), she claimed that if you were to buy two of these knives (God knows why one would want to, perhaps a Christmas present for that special someone?), you would get a THIRD one absolutely free (one for each member of the family?) as well as a special knife for carving meat, and a little knife, the purpose of which I don't remember.

While I'm sure the addition of a number of products to make the deal appear better value for money convinced quite a few of the customers, being a thrifty student I felt that I didn't need to spend £50 on a large set of sharp knives. The technique of “That's Not All” seems to have failed on me.

Maybe the effectiveness depends on the attractiveness of the original product. For instance, Jerry M. Burger (1986) conducted a series of seven experiments to demonstrate and explain the effectiveness of the “That's Not All Technique”, which involved selling cupcakes, something that would have definitely appealed to me. I will focus on just the first experiment here.  

Experiment 1.

60 adults and teenagers who came up to one of the psychology club bake sale booths set up at three different locations on a university campus participated as subjects (20 at each booth). The aim of the experiment was to see how effective it would be to include an additional product (cookies) a few seconds after giving the price for the cupcakes.

Two experimenters sat at the bake sale table with no prices listed. The cookies were hidden from view. Subjects were given one of two responses on a random basis, when they asked about the price.

Control response: The experimenters showed the cookies straight away saying that the package of two cookies and a cupcake cost 75 cents.

That's not all response: The first experimenter would say that the cupcakes cost 75 cents, but then the second experimenter would nudge him, they would talk for a few seconds, and afterwards the first experimenter would tell the customer that actually the price included two medium sized cookies.

The results were definitely in favour of the technique, as 73% of the “That's Not All” subjects purchased the cupcake and cookies package, while only 40% of the control subjects purchased the package as illustrated on the bar graph below.

So in fact the results of the experiment suggest that a high percentage of those who watched the presentation on the magic knife in Morrison's should have bought the whole set. However, there is a distinct difference between the experiment and the event in Morrison's. This is because in the experiment, the people who walked up to the stall were definitely interested in cupcakes in the first place, whereas I am sure that some of the people who agreed to listen to the presentation had 0% interest in knives (like me) and were only there for the free vegetable peeler. Thus, despite the empirical evidence showing the effectiveness of the "That's Not All" technique, it might not have worked so well in the situation I have described.  


Increasing Compliance by Improving the Deal: The That’s-Not-All Technique, Jerry M. Burger, Journal of Personality and Social Psychology, Vol. 51, No. 2, 277-283
Celebrity product endorsement - effective, or maybe not as much?

For this blog post I chose to write about persuading people to buy some particular product by having celebrities endorse the product in an advertisement. In this advertisement, a widely liked and positively thought-of person even out of his acting job – Brad Pitt, is starring in a Chanel no. 5 perfume commercial. He does get into a dreamy character, kind of filled with mystery (or he at least tried, which was ridiculed by some), yet one thing is clear – he can be related to the mentioned perfume, which unlike Brad Pitt, might be bought in most perfume shops.

How does this celebrity appearance in a commercial affect the sales of the brand or the product? Erdogan (1999) mentioned a number of studies where it was found that celebrity product endorsements are effective, but there is a matter of choosing the ‘right’ celebrity for a particular product involved. It was all simply explained by a classical conditioning model (look at Figure 2 below) – the creators of the advertisement assume that the celebrity evokes good and appropriate feelings, which in turn are attributed to the product itself, this way increasing the perceived value of that product compared to others.

A matter of finding the ‘right’ celebrity could be the reason why the Chanel no. 5 advertisement was seen by some as a flop, whereas celebrity advertising is still widely approved and thought to be effective. The attempt at persuasion was there, but the efficacy could possibly have been better by choosing a different celebrity. Maybe next time try advertising women’s perfume with the face of a woman?

Erdogan, B. Z. (1999). Celebrity Endorsement: A Literature Review. Journal Of Marketing Management15(4), 291-314.


The advert by Apple consists of celebrities modelling Beats headphones through taking selfies, or as referred to in this advert, "Solo Selfies". The advert continues with this repeated imagery of celebrities featuring the likes of rapper Nicki Minaj, model Jourdan Dunn and athlete Serena Williams also modelling the headphones in various colours whilst taking a Solo Selfie in various situations/environments.  

Apple uses the high status admirer altercast tactic through the use of celebrities to promote their headphones. This tactic is increasingly popular; especially in today’s celebrity-obsessed culture and companies take advantage of this by using celebrities, whom the younger crowd (their target consumers) are familiar with to endorse their products. Furthermore, another tactic used by Apple is the attractive-admirer altercast. We often wish emulate the celebrity lifestyle by modelling their behaviour and look, finding them physically attractive and looking up to them. Using this tactic, in order to immerse into the celebrity culture and seek their approval, the advert description encourages us to purchase the headphones and also take Solo Selfies.

A study by Ilicic and Webster (2011) investigated the use of celebrity endorsers and the effects it had on the attitude of consumers and purchase intentions. Participants, all university students, were asked to fill in a questionnaire regarding their TV viewing and their familiarity with the celebrity endorser (out of two Australian TV personalities). They were then asked to view photographs of both figures and note down how attached they felt to them. This attachment was experimentally manipulated meaning, one celebrity was used for the “strong attachment” condition whilst the other was for the “weak attachment” condition – this was based on a pre-test poll was taking where the public were asked which celebrity they found the most attractive. Participants were then assigned to the “one brand” or “multiple brands” condition where they viewed either one or three adverts with the belief that either celebrity had signed a contract with this brand, or all three brands for the multiple brands condition. They were then asked to evaluate their attitude towards the brand, the advert and their purchase intention.

The graphs below summarizes the results from the study:

As figures 2 and 3 show, participants in the strong attachment condition held a significantly high (positive) attitude towards both the ad and the brand compared to those in the weak attachment condition. This was true for both the single and multiple endorsement conditions. Meaning, the more attached you are to a celebrity the more likely you are to hold a positive attitude towards the advert and brand in which they are featured, this effect is consistent regardless of the number of endorsements.

Figure 4 shows purchase intention for all conditions strong/weak attachment and single/multiple endorsements. Purchase intention was high when there was strong attachment and single endorsement compared to when there was a weak attachment and single endorsement, this intention went down when the celebrity endorsed multiple brands.

Ilicic and Webster (2011) concluded that attachment to celebrities impacts our attitudes towards the adverts and the brand the celebrity is endorsing. This attachment also affects our purchase intentions; we are more likely to buy a product if it is endorsed by a celebrity we are strongly attached to and this study is one of many showing just how powerful celebrity endorsements are in the advertising world.


Ilicic, J., & Webster, C. M. (2011). Effects of multiple endorsements and consumer-celebrity attachment on attitude and purchase intention. Australasian Marketing Journal, 19, 230-237.

Why is my clock smiling at me?

If you do a quick Google search of clocks or watches, you may notice that most happen to be displaying the time 10:08 (or 10:09, 10:10, or aesthetically similar times like 1:51 or 1:52). This is hardly a coincidence, and is, in fact, called the “10:08 rule” amongst advertisers. Why is this the case? In the past, most clocks and watches used to be tuned to 8:20, which was eventually changed because this made the clock’s face look a little too sad. So clock and watch sellers decided to turn their frowns upside down (literally), and have since started setting clocks to a time that more closely resembles a smile. This rule is followed by many of the top watch companies in the world, including Swatch, Ulysse Nardin, Rolex, The Hamilton Watch Company, and Timex, which exclusively photographs its products and displays them in shop windows at 10:09:36 (The New York Times, 2008). Why this happens is because of the phenomenon pareidolia, which is the tendency for people to see significance in insignificant things, for example spotting faces in randomness. Seeing the smiling watch makes us feel good, which we to associate with the product, which we then may be more likely to be persuaded to purchase.Petty, Schumann, Richman and Strathman (1993) conducted a study on how positive moods increased the effectiveness of a persuasive message. In their experiment, participants were asked to write about a recent positive life event for around 5 minutes (positive mood condition) or listened to 5.5 music (neutral mood condition). They then listened to either a strong (persuasive) or weak (unpersuasive) argument editorials about a particular topic they knew nothing about. Finally, participants completed a Need for Cognition Scale, which measures “the tendency for an individual to engage in and enjoy thinking" (Cacioppo & Petty, 1982, p. 116). High and low Cognition groups were created.
Following this, participants were rated on the attitude index and thought index. The former involved rating the argument editorial on 5 scales: good-bad, negative-positive, wise-foolish, agree-disagree and not at all persuaded-definitely persuaded. The latter involved participants write 21 thoughts they had while listening to the editorial and to rate them as positive, negative or neutral. Participants were asked about their feelings before, during and after the message presentation and given a score on the manipulation scale. Finally, they were asked to recall as many arguments from the message as possible.The results can be seen in Figure 1 below. Those in the positive condition reported feeling more positively than those in the neutral mood condition. Both weak and strong arguments were rated as equally convincing. However, participants in the positive mood conditions rated the arguments as more convincing than those in the neutral mood conditions F(1, 125) = 4.96, p < .05. This was independent of the strength of the argument and the participant’s Need for Cognition scores.

The fact that the strength of the argument was not relevant to how convincing the message was is particularly relevant to the clock and watch example – as long as participants were experiencing a positive mood, they were more likely to be persuaded. Thus, a clock with a smiling face may be a fairly persuasive advertising argument in itself.References               Andrew Adam Newman (2008). Why Time Stands Still for Watchmakers. [ONLINE] Available at: [Last Accessed 30/1/2015].Cacioppo, J. T., & Petty, R. E. (1982). The need for cognition. Journal of personality and social psychology, 42, 116.
Petty, R. E., Schumann, D. W., Richman, S. A., & Strathman, A. J. (1993). Positive mood and persuasion: Different roles for affect under high-and low-elaboration conditions. Journal of personality and social psychology, 64, 5.

Work hard to get it, then love it

This Fantastic Delites commercial shows the company planting an interactive machine on a public square. People find out that for performing a specific task outlined by the machine, they get a Fantastic Delites product as a reward. We can see that the tasks start easy - for example pushing a button 50 times; and get increasingly difficult, showing us how one person pushed the button 5000 times just to get a Fantastic Delite.

This video advertisement has captured my interest especially since it gives people challenging or fun tasks to do while covering up the fact that these activities work to subtly advertise the product which comes as a reward at the end.

In 2012, the company behind the Fantastic Delites has published the above ''How far will you go for Fantastic Delites?'' advert, later followed in 2014 by ''How far would you queue for Fantastic Delites?'' video advert, suggesting that the techniques
used in the first advert have been a success.

Both of these advertisements feature a mixture of persuasion techniques. First of all, perhaps the most obvious technique we can see at play here is Effort Justification. People have been asked to expend large amounts of effort to obtain an object, which leads them to justifying the expenditure by increased liking of the object.

This technique can prove especially useful for someone wanting to establish a name and liking on the market while using one marketing advertisement.

Aronson and Mills have conducted a study to show that the more a person suffers in order to obtain something, the greater will be the tendency to evaluate it positively. They have created a specific experiment in which they varied the severity of an initiation required for an admission into a group, for example in the severe initiation condition participants had to read some embarassing material out loud, and measured the participants' liking for each group afterwards.

Table 1 shows how the participants in the severe condition rated both the discussion and other participants higher than the mild condition.

 Moreover, this effect is combined with the Public Audience effects - where the presence of an audience can increase concerns for maintaining a positive public image, resulting in an increased compliance (when the request is one that is socially approved). This would make sense of how such large number of people were willing to participate in the machine's challenges, no matter how nonsensical.

The public audience effects have been shown by Rind and Benjamin in their study called Effects of Public Image Concerns and Self-Image on Compliance. Male shoppers were asked to purchase ruffle tickets to support the United Way and it was found that male shoppers with a female companion purchased almost twice as many tickers compared to lone male shoppers.


Aronson, E. & Mills, J. (1959). The effect of severity of initiation on liking for a group. Journal of Abnormal and Social Psychology, 59, 177-181.

Rind, B. & Benjamin, D. (1994). Effects of public image concerns and self-image on compliance. Journal of Social Psychology, 134, 19-25.

Diana Drgonova

You will suffer and enjoy every moment...

This leaked controversial advert of the new spicy Domino's Pizza is rumoured to have been inspired by the upcoming erotic film 'Fifty Shades of Grey', where the main character exhibits a strong preference towards BDSM. The teasing slogan promises the pizza would make one 'suffer and enjoy every moment'.

The advert uses the technique of Association, described by Pratkanis (2007) as 'linking of an issue, idea, or cause to another positive or negative concept in order to transfer the meaning from the second to the first'. In this case, the sensations to be experienced while eating the pizza are implied to be similar to those associated with BDSM practices.

The use of this technique can be explained by the effectiveness of the use of sexual appeal in advertising, particularly to strengthen subsequent brand recall. This was explored by Richmond & Hartman (1982) by testing the recall by participants of brands associated with sexual elements.
The participants were asked to look at 8 adverts and categorise into 4 groups - Functional (product can be showed in a straightforward sexual presentation), Fantasy (with roots in psychological literature, linked to daydreaming and fantasies), Symbolism (cultural, Freudian symbols), and Inappropriate (advertising making degrading and insulting suggestions). A subsequent task involved an interview where the participants were associating the cues (from the headline, copy or illustration) with the brand name.
As demonstrated by Table 4, the adverts within the Functional and Fantasy categories exhibited the highest rate of brand recall. In turn, the Symbolism category showed varying results, depending on how adequate was the use of the symbols.

The Domino's advert links the product with both the functional element (by highlighting its characteristics that are directly in parallel with BDSM), and the fantasy element, potentially encouraging people to fantasise about the pizza the same way as they might about sex (According to Richmond & Hartman (1982), 95% of participants have admitted to having had sexual fantasies). It could therefore be suggested that by promoting its product as one having certain sexual appeal, Domino's was hoping to increase its recognition and brand recall.

Pratkanis, A. R. (Ed.). (2007). The science of social influence: Advances and future progress. Psychology Press.
Richmond, D., & Hartman, T. P. (1982). AN EXPLORATORY-STUDY OF... SEX APPEAL IN ADVERTISING. Journal of Advertising Research22(5), 53-61.

Protect Syria's Children

At the centre of any war lie the innocent civilians being injured and killed. The Syrian civil war which has lasted for almost three years has been no exception. Since the start of the conflict, 3 million people, reported to be mostly women and children, have fled the country while over 200,000 have died.

The tragic events have rightly been matched by a sizeable charity drive seeking to protect these innocent victims. In April 2014, Disasters Emergency Committee reported to have risen £27m for the Syrian crisis. One basis for this successful appeal lies with tact altercasting, where the receiver of the message is placed into a role as a result of the source. In the instance of the picture below and much of the Syrian appeal, the receiver is placed into the role of the protector where a donation can help those in need.

Figure 1. Unicef appeal for donations to help aid in Syria.

While previous research showed credibility of the source to be a main effect, Pratkanis and Gliner (2004-2005) provided an altercasting theory whereby persuasiveness is dependent on a message-source interaction. In their study, students received either a message on nuclear disarmament or the existence of a tenth planet from either a child or an expert in the field. The participants were then asked to complete a 9 point agreement scale for five statements arguing the strength or weakness of the argument they received. The results of message effectiveness are illustrated in Figure 2.

Figure 2. Mean message effectiveness as a result of changes in source and message type.

The results show that instead of source credibility being the most important factor in message persuasion, an interaction is present where the source and message type combination influences effectiveness level. Pratkanis and Gilner found that the nuclear disarmament message is made more effective by the child placing the recipient in a role of protector. If the same message was being provided by an expert, the recipient is placed in an "unknowing public" role instead. Praktanis and Gilner argue that with becoming a protector, the recipient feels more responsibility to act upon the message.

This runs true for the Syrian appeal which has raised a considerable amount. The use of children to portray the message places those in a more privileged situation to “protect” by donating.

Pratkanis, A. R., & Gliner, M. D. (2004-2005). And when shall a little child lead them? Evidence for an altercasting theory of source credibility. Current Psychology, 23, 279-304.

Predictions 'predict' behaviours

Empress of China is a hot TV drama about the saga of China’s first female emperor. There are many clever episodes where techniques of persuasion are used in the drama and the following is an example. Princess Gaoyang commanded her husband Fang Yi’ai to egg her third eldest brother, the King of Wu, to rebel against her ninth eldest brother, the current Emperor. Rebellion was refused and emperor's son-in-law asked the Princess why he needed to mention the rebellion before the King of Wu. The Princess said:” The beliefs of human are like the seeds of the flowers. If they are not exposed to the sun, they will become withered quickly. Once they are revealed, whether by the people himself, or by others, they get the chance of becoming true. The same is with King of Wu’s belief. If his rebellion beliefs were never said aloud, they would only sparkle in his unconsciousness. Now that you have mentioned them, they may be activated in his mind. ”