Effects of different type of hand gestures in persuasive speech on receiver's eveluations - Maricchiolo et. al. (2009) - Article

What is this article about?

When studying gestures, they are often studied by looking at hand gestures in conversations. There are many studies that looked at the speech-gesture relationship. Other studies have looked at the gesture from a perceiver’s point of view and these studies argue that gestures are produced in order to aid comprehension by the listener. Approaches in understanding hand gestures suggest that there are different categories of gestures, and that these categories might be perceived by listeners in different ways and therefore also perform different functions. In the literature, hand movements are distinguished as illustrators or ideational gestures (related to semantic content of concurrent speech), conversational gestures (accompanying speech without a relation to the semantic content) and adaptors (self-addressed and object-addressed or person-addressed movements).

Illustrators used during speech improve the addressee’s attention, recognition, understanding and memory about the content described by the speakers. Illustrators then have the property of clarifying the content of the discourse. According to some studies, object-adaptors and self-adaptors are associated with the perception of anxiety, nervousness and sometimes deception. But, there are also studies that have found no link between these variables. There are no studies on the perception of other types of gestures. There is also no study that has considered all gesture categories at the same time. Gestures can also provide information about the speaker, for example his or her emotions or attitudes. Listeners can use gestures to evaluate the speaker’s features and his or her intentions.

Studies on interpersonal and social perception and judgment showed that two dimensions underlie most judgments. The definitions of these dimensions may vary, but one of these dimensions refers to attributes such as warmth, friendliness and sociability, while the other refers to attributes such as agency, competence and efficacy. The studies on persuasion look at variables and processes that change or form attitudes, and try to identify the role of the features of the speakers, the receivers and messages in the process. These studies suggest that there is a certain feature, like expertise and/or attractiveness that would have a positive effect on attitude formation and on the receiver’s evaluation of source and message. According to some studies, a communicator of a persuasive message may improve his or her efficacy through an effective communication style. Verbal communication style is the main component of powerful communication, but nonverbal characteristics can also play a big part. Studies have looked for nonverbal parameters that have been associated with perceptions of competence, credibility and effectiveness of the communicator. Research has found that the degree of liking, which was nonverbally communicated by high speech volume, high eye contact and high speech rate, was positively correlated with the perceived persuasiveness of communication. Other studies found that many nonverbal behaviours were associated with different social judgments. Different nonverbal styles can affect ratings of likeableness, competence, powerfulness, anxiety and social influence.

What were the experiments in this study?

Experiment 1

Only a few researchers have looked at the effect of hand gestures in the perceived effectiveness of the speaker. There are, however, no studies that have systematically and experimentally examined the effect of only hand gestures on perception of speaker’s effectiveness during persuasive communication. The authors of this article decided to experimentally test the effect of the main hand gesture categories on perception and evaluation of a speaker and their communication. The authors kept the verbal content constant and prepared one message in five different versions, manipulating only the hand gestures (ideational, self-addresses adaptors, other-addressed adaptors, conversational and absence of gestures). After viewing a video of a speaker, each participant had to evaluate the speaker and the message through a self-administered questionnaire. They also had to express their attitude and vote their intention to the issue presented in the message. The goal of this study was to compare multiple kinds of gestures among themselves and against a no-gesture control condition. So, they wanted to test the effect of gestures on speaker and message perception and on the persuasion process.

The authors hypothesized that the manipulation of the speaker’s gestures would affect the listener’s perception. The dependent variables were: communicative effectiveness, composure, competence, warmth of the speaker and persuasiveness of the message. The authors think that ideational gestures and conversational gestures will increase effectiveness and persuasiveness of the perceptions, while self-addressed adaptors and other-addressed adaptors will decrease message persuasiveness. The authors also thought that there would be no effects of gestures on warmth, since previous research showed that this feature was related to other nonverbal features like eye and smile movements.

Participants viewed a video of a woman who provided arguments for introducing a 20% increase of university fees for the students of the university in which the experiment was conducted. There were five conditions, and in every condition the woman stated exactly the same thing, but used other gestures:

• Ideational gestures: these are iconic and metaphoric gestures and they are linked to the semantic content of speech.
• Conversational gestures: these are rhythmic and cohesive gestures and they are linked to the speech structure
• Object-addressed adaptors: hand movements of contact with objects
• Self-addressed adaptors: hand movements of contact with parts of one’s own body
• Absence of gestures: the woman kept her hands on the table without moving them

The amount of gestures, 36 gestures per video, was kept equal. Other nonverbal parameters (posture, leg and head movements, facial expression and physical appearance) were controlled for and thus maintained constant. The actress was always standing behind a white table and her legs weren’t visible. On the table there was a pen and a spectacle-case (touched in the object-addressed adaptors condition). She wore a black dress (neutral colour) and kept a constant posture. After viewing the video, participants filled in a questionnaire with questions about the speaker, her message persuasiveness, her communicative style, the participant’s attitude towards the fees increase and his or her attention to vote about it. The participants also had to evaluate along a response scale the degree of their attention to and the perceived effectiveness of each one of the following features: facial expression of the speaker, hand gestures, physical appearance of the speaker, posture, clothing and gaze of the speaker. This was a manipulation check to control for the effects of other, nonverbal features.

The results show that subjects in the ideational gestures condition rated the speaker’s hand gesture significantly as more effective than those in the object-addressed and self-addressed adaptors condition. There were no significant effects of gesture type on the evaluation of effectiveness of the other features of the speaker’s communication style (like physical appearance and facial expression). The data also showed that participants in the no gesture condition paid less attention to hand gestures than participants from the other condition. Participants from the object-addressed adaptors condition paid more attention to speaker’s hand gesture than the subjects in the ideational gesture condition. There were no effects of gesture type on the attention to the other features of the speaker’s communicative style. The results of this study show that these five conditions are perceived as different, only in the speaker’s hand gesture, and not in other features of a speaker’s communicative style. Like predicted, no effect of gesture type was significant for warmth, attitude or vote intention. People in the ideational gesture condition, the conversational gesture condition and the no gesture condition evaluated speaker composure higher than participants from the self-adaptors and other-adaptors conditions. The speaker was perceived as more competent in the object-adaptors and ideational conditions compared to the condition of the absence of gestures. In the object-addressed adaptor condition, conversational gesture condition and ideational gesture condition, participants rated the effectiveness of the speaker’s communicative style higher. Also, in these conditions, participants evaluated message persuasiveness higher than in the no gesture condition.

Experiment 2

The presence or absence of gestures could alter speech rate and intonation pattern. The researchers therefore decided to perform a second experiment in order to control for the possible effects of vocal features on the measures. There were five audio-only versions of the message from experiment 1 and these were submitted to another group of participants. All five gesture conditions, but only in vocal form (so no video), were presented to the participants. All the participants were presented all types of the messages. After each message, the participants filled in a questionnaire containing the same measures as in Experiment 1.

This is a rather short experiment and the results showed that on the basis of audio only, participants perceived and evaluated the speaker, her communicative style and the message of the five different experimental conditions, equally. This means that the differences found in Experiment 1 are attributable to the speaker’s visual gestures and not to any audio cues.

What can be concluded?

For the first time, the authors showed in a true experiment that hand gestures cause differences in audience perception of the message sender as well as the message itself. Participants paid more attention to the conditions in which gestures were present than in the condition of no gestures present. Effectiveness was higher for ideational than for self-addressed or other-addressed adaptors. The five conditions didn’t affect evaluations of speaker’s facial expressions, physical appearance or gaze. The hand gesture type affected some factors of speaker evaluation and some of the other dependent variables, like speaker composure, speaker communication style effectiveness, competence and message persuasiveness. The results of the study show that the experimental manipulation of a speaker’s hand gesture type can affect interpersonal perception and judgment. Consistent with previous studies, negative effects of adapters on composure were found. Results showed that linked-to-speech gestures in are usually better than non-linked-to-speech gestures in for the message and speaker evaluations.

Ideational gestures are seen as more effective and make the speaker appear more competent and composed and as having a more effective communication style and conveying a more persuasive message. This type of gesture is the gesture type with the strongest positive effect. In the gesture absence condition, speakers who are presenting a message that is contrary to the receiver’s opinion, there is an overall negative evaluation. This is probably because the gestures do not interact with speech, so the perceiver only pays attention to the negative message. Some researchers claimed that gesture-speech occurrence is culturally variable and the researchers of the current study think that the results of the gesture absence condition are in need of cross-cultural comparison. The findings of the current study (the differences among different gesture types) cannot be explained by differences in vocal signals. This was proven by Experiment 2.

Further research should look at different types of messages. This study conveyed a negative message, but would a positive message have other effects? Also, further research could address possible relations among the dependent variables.