Using Psychological Cues to Persuade

• Created dominant and submissive computer personalities

• Chose as participants people who were at extremes of dominant or submissive

• Mixed and matched computer personalities with user personalities

• Result: Participants preferred computers whose “personalities” matched their own.

The evidence from this study suggests that computers can motivate and persuade people more effectively when they share personality traits with them—at least in terms of dominance and submission. For designers of persuasive technology, the findings suggest that products may be more persuasive if they match the personality of target users or are similar in other ways.

The Affiliation Study

While running the personality study, we set out to conduct another study to examine the persuasive effects of other types of similarity between people and computers. ^{[23 ]} For this second study we investigated similarity in affiliation— specifically, the persuasive impact of being part of the same group or team. The study included 56 participants, mostly Stanford students along with a few people from the Silicon Valley community. All the participants were experienced computer users.

In this study, we gave participants the same Desert Survival Problem to solve. We assigned them to work on the problem either with a computer we said was their “teammate” or with a computer that we gave no label. To visually remind them of their relationships with the computers, we asked each participant to wear a colored wristband during the study. If the participant was working with a computer we had labeled as his or her teammate, the participant wore a blue wristband, which matched the color of the frame around the computer monitor. The other participants—the control group—wore green wristbands while working with the blue-framed computers. For both groups, the interaction with the computer was identical: the computer gave the same information, in the same style.

Research Highlights: The Affiliation Study

• Participants were given a problem to solve and assigned to work on the problem either with a computer they were told was a “teammate” or a computer that was given no label.

• For all participants, the interaction with the computer was identical; the only difference was whether or not the participant believed the computer was a teammate.

• The results compared to responses of other participants: people who worked with a computer labeled as their teammate reported that the computer was more similar to them, that it was smarter , and that it offered better information. These participants also were more likely to choose the problem solutions recommended by the computers.

After completing the study, we examined the data and found significant differences between the conditions. When compared with other participants, people who worked with a computer labeled as their teammate reported that the computer was more similar to them, in terms of approach to the task, suggestions offered, interaction style, and similarity of rankings of items needed for survival. Even more interesting, participants who worked with a computer labeled as a teammate thought the computer was smarter and offered better information.

In addition, participants who worked on the task with a computer labeled as a teammate reported that the computer was friendlier and that it gave higher quality information. Furthermore, people who perceived the computer to be similar to themselves reported that the computer performed better on the task. ^{[24 ]}

During the study we also measured people’s behavior. We found that computers labeled as teammates were more effective in influencing people to choose problem solutions that the computer advocated. In other words, teammate computers were more effective in changing people’s behavior.

All in all, the study showed that the perception of shared affiliation (in this case, being on the same “team”) made computers seem smarter, more credible, and more likable—all attributes that are correlated with the ability to persuade.

Among people, similarity emerges in opinions and attitudes, personal traits, lifestyle, background, and membership. ^{[25 ]} Designers of persuasive technology should be aware of these forms of similarity and strive to build them into their products.

One company that has done a good job of this is Ripple Effects, Inc., which “helps schools , youth-serving organizations, and businesses change social behavior in ways that improve performance.” ^{[26 ]} The company’s Relate for Teens CD-ROM leverages the principle of similarity to make its product more persuasive to its target audience—troubled teens. It conveys similarity through the language it uses, the style of its art (which includes graffiti and dark colors), audio (all instructions are given by teen voices), and photos and video clips that feature other, similar teens. Researchers at Columbia University and New York University have shown that the product produces positive effects on teen behavior, including significant reductions in aggressive acts, increases in “prosocial” acts, and improvements in educational outcomes . ^{[27 ]}

People are more readily persuaded by computing technology products that are similar to themselves in some way.

As this example and the Stanford research suggests, designers can make their technology products more persuasive by making them similar to the target audience. The more that users can identify with the product, the more likely they will be persuaded to change their attitudes or behavior in ways the product suggests.

Ethical and Practical Considerations

The two studies just described suggest that people are more open to persuasion from computers that seem similar to themselves, in personality or affiliation. In addition to similarity, a range of other persuasion principles come into play when computers are perceived to have a psychology. Computers can motivate through conveying ostensible emotions, such as happiness, anger, or fear. ^{[28 ]} They can apply a form of social pressure. ^{[29 ]} They can negotiate with people and reach agreements. Computers can act supportively or convey a sense of caring.

Designing psychological cues into computing products can raise ethical and practical questions. Some researchers suggest that deliberately designing computers to project psychological cues is unethical and unhelpful. ^{[30 ]} They argue that psychological cues mislead users about the true nature of the machine (it’s not really having a social interaction with the user). Other researchers maintain that designing computer products without attention to psychological cues is a bad idea because users will infer a psychology to the technology one way or another. ^{[31 ]}

While I argue that designers must be aware of the ethical implications of designing psychological cues into their products, I side with those who maintain that users will infer a psychology to computing products, whether or not the designers intended this. For this reason, I believe designers must embed appropriate psychological cues in their products. I also believe this can be done in an ethical manner.

The Oscilloscope Study

My belief that users infer a psychology to computing technology stems in part from research I conducted in the mid-1990s for a company I’ll call Oscillotech, which made oscilloscopes. The purpose of the research was to determine how the engineers who used the scopes felt about them.

What I found surprised Oscillotech’s management. The scopes’ text messages, delivered on a single line at the bottom of the scopes’ displays, were somewhat harsh and at times unfriendly, especially the error messages. I later found out that the engineers who wrote these messages, more than a decade earlier, didn’t consider what impact the messages would make on the scope users; they didn’t think people would read the messages and then infer a personality to the measuring device.

They were wrong. My research showed that Oscillotech’s scopes made a much less favorable impression on users than did a competitor’s scopes. This competitor had been gaining market share at the expense of Oscillotech. While many factors led to the competitor’s success, one clear difference was the personality its scopes projected : the messages from the competitor’s scopes were invariably warm, helpful, and friendly, but not obsequious or annoying.

What was more convincing was a controlled study I performed. To test the effects of simply changing the error messages in Oscillotech’s scopes, I had a new set of messages—designed to portray the personality of a helpful senior engineer—burned into the Oscillotech scopes and tested users’ reactions in a controlled experiment.

The result? On nearly every measure, people who used the new scope rated the device more favorably than people who used the previous version of the scope, with the unfriendly messages. Among other things, users reported that the “new” scope gave better information, was more accurate, and was more knowledgeable. In reality, the only difference between the two scopes was the personality of the message. This was the first time Oscillotech addressed the issue of the “personality” of the devices it produced.

This example illustrates the potential impact of psychological cues in computing products. While it is a benign example, the broader issue of using computer technology to convey a human-like psychology—especially as a means to persuade people—is a controversial area that has yet to be fully explored and that is the subject of much debate. (Chapter 9 will address some of the ethical issues that are part of the debate.)

^{[15 ]} For more on the predictability of attractiveness, see the following:

a. M. Cunningham, P. Druen, and A. Barbee, Evolutionary, social and personality variables in the evaluation of physical attractiveness, in J. Simpson and D. Kenrick (eds.), Evolutionary Social Psychology (Mahwah, NJ: Lawrence Erlbaum, 1997), 109–140.

b. J. H. Langlois, L. A. Roggman, and L. Musselman, What is average and what is not average about attractive faces? Psychological Science, 5: 214–220 (1994).

^{[16 ]} When it comes to emotions and computers, Dr. Rosalind Picard’s Affective Computing Research Group at MIT has been blazing new trails. For more information about the group’s work, see http://affect.media.mit.edu/.

^{[17 ]} My research involving engineers and social responses to computer devices was performed for HP Labs in 1995.

^{[18 ]} H. Tajfel, Social Identity and Intergroup Relations (Cambridge, England: Cambridge University Press, 1982).

^{[19 ]} R. B. Cialdini, Influence: Science and Practice, 3rd ed. (New York: HarperCollins, 1993).

^{[20 ]} Persuasion scholar Robert Cialdini writes , “As trivial as . . . similarities may seem, they appear to work. . . . even small similarities can be effective in producing a positive response to another.” Robert B. Cialdini, Influence: Science & Practice (Boston: Allyn and Bacon, 2000). See also H. Tajfel, Human Groups and Social Categories (Cambridge: Cambridge University Press, 1981).

See also H. Tajfel, Social Identity and Intergroup Relations (Cambridge, England: Cambridge University Press, 1982).

^{[21 ]} C. I. Nass, Y. Moon, B. J. Fogg, B. Reeves, and D. C. Dryer, Can computer personalities be human personalities? International Journal of Human-Computer Studies, 43: 223–239 (1995).

^{[22 ]} For each study, we adapted the desert survival task from J. C. Lafferty and P. M. Eady, The Desert Survival Problem (Plymouth, MI: Experimental Learning Methods, 1974).

^{[23 ]} J. M. Digman, Personality structure: An emergence of the five-factor model, The Annual Review of Psychology, 41: 417–440 (1990).

^{[24 ]} C. I. Nass, B. J. Fogg, and Y. Moon, Can computers be teammates? Affiliation and social identity effects in human-computer interaction, International Journal of Human- Computer Studies, 45(6): 669–678 (1996).

^{[25 ]} B. J. Fogg, Charismatic Computers: Creating More Likable and Persuasive Interactive Technologies by Leveraging Principles from Social Psychology, doctoral dissertation, Stanford University (1997).

^{[26 ]} Part of my list about similarity comes from

S. Shavitt and T. C. Brock, Persuasion: Psychological Insights and Perspectives (Needham Heights, MA: Allyn and Bacon, 1994).

^{[27 ]} http://www.rippleeffects.com.

^{[28 ]} To read about the research, see http://www.rippleeffects.com/research/studies.html.

^{[29 ]} To get a sense of how computers can use emotions to motivate and persuade, see R. Picard, Affective Computing (Cambridge, MA: MIT Press, 1997). See also the readings on Dr. Picard’s Web site: http://affect.media.mit.edu/AC_readings.html.

^{[30 ]} C. Marshall and T. O. Maguire, The computer as social pressure to produce conformity in a simple perceptual task, AV Communication Review, 19: 19–28 (1971).