Interaction Studies - Volume 22, Issue 3, 2021

This special issue addresses how aspects of the communicative situation influence how influential persuasive utterances (or other strategies of influence) are in their contexts of use. Specifically, we study the effects of interactional, speaker-, addressee- and channel-related factors and of the interpersonal relationship between speaker and hearer, as well as the effects of referring to the shared context itself. The papers combined in this special issue provide evidence for the considerable impact of the here and now of the interactional context on the persuasiveness of strategies of influence and contribute to our understanding of mechanisms of persuasion.

The concept of vocal charisma has changed in the past decades from something that people have to something that people do, thereby stimulating research on how vocal charisma can be created and improved. Broadening the perspective on vocal charisma beyond the speaker’s performance itself to the context of the speech, we conducted acoustic-prosodic analyses of public speeches of two prominent Israelian politicians – Benjamin Netanyahu and Benny Gantz. The speech material consisted of 311–516 prosodic phrases per politician from the election campaigns 2019–2020 and, crucially, was balanced so as to include an equal number of pre- and post-election speeches. Results show a superiority of Netanyahu over Gantz in almost all facets of vocal charisma, although Gantz caught up over time. Moreover, unlike Gantz, Netanyahu showed a strong adaptation of his vocal charisma patterns to before- and after-election contexts. Scrutinizing this versatility difference, an additional perception experiment with 42 listeners and excerpts from the two politicians’ speeches was carried out. Results show that Netanyahu’s speech excerpts were, unlike those of Gantz, mainly rated as more charismatic in those contexts in which they were performed. Gantz’ post-election speech excerpts, by contrast, were primarily rated as not fitting into that context, i.e., as unfolding their charisma better in a pre-election context. Moreover, listeners also rated Netanyahu as overall more charismatic than Gantz. The combined production and perception evidence suggests the relevance of context in the evaluation and interpretation of vocal charisma signals.

Science communication has gained high importance in the current knowledge and risk society. Nevertheless, there is still a lack of qualitative studies on how non-experts and experts engage in opinionated scientific debates and which linguistic devices they use to gain influence on other people’s attitudes toward a scientific issue.

In our study, we examine dialogical modes of science communication (i.e. weblogs) used by bloggers and audiences to engage into opinionated discourse about scientific endeavors. As those exchanges easily lead to controversies between different points of views, stances and attitudes, we focus from a rhetorically-driven linguistic perspective on devices to persuade the other participants and readers and to control the discourse. Hence, we ask which linguistic instruments are used to gain influence on influence. The aim of our study is to get deeper insights into the persuasive strategies mainly used in those forms of external science communication.

Mental or computer simulation of cause and effect of certain behaviors is a recognized approach to changing one’s attitude or triggering an action. Meanwhile, psychology research results suggest that frequency of simulation may affect the corresponding persuasiveness. This paper argues that with always-on sensing and data-driven visualization technologies, interactive tangible systems can be designed to simulate hypothetical outcomes of real-life behaviors in everyday contexts, which repeatedly stimulate users’ imagination of behavioral consequences and thereby behavioral intentions. To investigate the effect, a working prototype of Incingarette, including a smart ashtray in connection with a digital picture frame, was built. When the ashtray is used for smoking, the digital picture is incrementally covered by virtual dust. Field trials involved participants in five daily smoking sessions. Post-session surveys show increasingly stronger perceived causality between smoking and the simulated outcomes, increasingly more vivid mental imagery of consequences, and increasingly intense intention to reduce smoking. Results suggest that repeatedly presenting simulated outcomes cognitively linked to real-life behaviors can increase behavioral intentions.

Persuasive social robots can influence human behavior through giving advice. The current study investigates whether references to prior discourse and signals of empathy make an advice-giving robot an even more effective persuader and whether participants follow the robot’s advice and drink even more water when the robot additionally uses these strategies. We recruited students and university staff for a lab-study in which three different robot personalities on the same robot type presented health-related information. In one condition, the robot gave advice and referred to something mentioned earlier in the conversation (i.e., to dialog history), in another condition, the robot gave advice and used empathic signals, and in the third condition, the robot gave advice only. Our results show that participants drank significantly more when the advice-giving robot also used the persuasive strategies of empathy and references to dialog history than when the robot only gave advice. This study shows that both strategies increase the persuasiveness of the robot and makes it more influential.

Previous experimental findings support the hypothesis that laughter and positive emotions are contagious in face-to-face and mediated communication. To test this hypothesis, we describe four experiments in which participants communicate via a chat tool that artificially adds or removes laughter (e.g. haha or lol), without participants being aware of the manipulation. We found no evidence to support the contagion hypothesis. However, artificially exposing participants to more lols decreased participants’ use of hahas but led to more involvement and improved task-performance. Similarly, artificially exposing participants to more hahas decreased use of haha but increased lexical alignment. We conclude that, even though the interventions have effects on coordination, they are incompatible with contagion as a primary explanatory mechanism. Instead, these results point to an interpretation that involves a more sophisticated view of dialogue mechanisms along the lines of Conversational Analysis and similar frameworks and we suggest directions for future research.

In the near future, robots will function in social roles and attempt to influence the user’s behavior and / or thinking. The current contribution analyses how to influence robot influence: Persuasive robots can be personalized to make them more effective. We present an overview of (1) the user characteristics to which persuasive robots can be personalized, (2) considering the specific current situation of a user; and (3) the robot characteristics that can be personalized. Thereby, we give an overview of how the persuasive robot’s physical appearance, behavior, (perceived) cognition and affect can be influenced to characteristics of the user (personalized) in order to make the robot more persuasive and thereby to understand better how the persuasive power of an embodied artificial social entity can be influenced.

In this paper, we analyze what effects indicators of a shared situation have on a speaker’s persuasiveness by investigating how a robot’s advice is received when it indicates that it is sharing the situational context with its user. In our experiment, 80 participants interacted with a robot that referred to aspects of the shared context: Face tracking indicated that the robot saw the participant, incremental feedback suggested that the robot was following their actions, and comments about, and gestures towards, the shared physical situation and linguistic references to the dialog history indicated to participants that the robot had learned from the interaction and perceived its surroundings. The results show that especially the linguistic and gestural references to the shared context have a significant influence on participants’ compliance with the robot’s suggestions. Thus, indicating that it is ‘in the same boat’ with the user, i.e. that it is sharing the situational context, increases a robot’s persuasiveness during advice giving.