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When searching for health information, many people use the internet as their first source of information. In online health forums, for example, users post their questions and exchange health advice. In recent years, information givers from various professions have begun to use positive language (indicated by the frequent use of positively valenced adjectives) to communicate their information and persuade their audiences.
The goal of the current study was to answer the following research questions: (1) How does positive language, in comparison to neutral language, influence the trustworthiness of a person arguing in an online health forum and the credibility of their health claims; (2) How does working for a university, compared to working for a lobbying organization, influence the trustworthiness of a person arguing in an online health forum and the credibility of their health claims; and (3) Do the two factors of language style and professional affiliation interact with each other to influence trustworthiness and credibility judgments?
In a 2 × 2 between-subject experiment, 242 participants read a post from an online health forum and subsequently rated the trustworthiness of the forum post author and the credibility of their information. Within the post, the professional affiliation (scientist vs lobbyist) and language style (neutral vs positive) of the forum post author was varied.
When the forum post author used a positive language style, they were perceived as less trustworthy (high Machiavellianism [
When searching for health information, information seekers evaluate the language style of forum posts to decide whether forum post authors are trustworthy and their information is credible.
When searching for health information, many people use the internet as their first source of information [
For example, one study showed that unfamiliar health information is rated as being more credible if the information source has a professional affiliation indicating they are a medical expert (eg, Dr. William Blake, HIV specialist) rather than a nonexpert (eg, Tim Alster, a high school freshman) [
Using positive language, indicated by the implementation of positively valenced adjectives (eg, great, amazing, outstanding), is another language style that seems to be on the rise when it comes to communicating health and science information. For example, in an article for the National Academy of Sciences, the authors did not just neutrally write about an antioxidant. Instead, they chose to write about an “outstanding antioxidant” [
Authors who use such positive language might want to stress the importance of their advice or the quality of their research. However, is this a reasonable strategy in the context of health communication? Moreover, how does positive language influence the trustworthiness of health communicators and the credibility of their health claims? To our knowledge, no research has addressed these questions so far. However, it is known from previous research that businesses often use positive language to generate a favorable view of their prospects and performances [
Hence, diverse effects of positive language seem to be possible. If an information source uses positive language when writing about the effectiveness of a specific drug, information seekers can interpret this language choice in different ways. On the one hand, information seekers might conclude that the positive language style shows that the information source is highly convinced of the effectiveness of the drug and wants to express their excitement. In this case, the positive language style might function as a quality cue that increases credibility and trustworthiness. On the other hand, the positive language style might remind information seekers of commercials that are designed to persuade their audiences and increase sales. In this case, the positive language style might function as a negative cue that decreases credibility and trustworthiness. Furthermore, one might argue that positive language is more likely to be perceived as a quality cue if a scientist uses it because scientists are typically not interested in increasing the sales of a specific drug. However, one could also argue that people expect a scientist to be neutral and objective, and therefore the use of positive language will be perceived as a negative cue.
This example and the previously discussed literature illustrate two things: (1) many authors with different professional affiliations use positive language, indicated by the implementation of positively valenced adjectives, to communicate health information; and (2) little is known about how such positive language influences the trustworthiness of health communicators and the credibility of their health claims. Therefore, we designed an experiment to investigate how different language styles and different professional affiliations influence the trustworthiness of health communicators and the credibility of their health claims. During the experiment, participants read a post from an online health forum and subsequently rated the trustworthiness of the forum post author and the credibility of their information. Within the forum post, we varied the professional affiliation of the forum post author (whether the person was a scientist or a lobbyist) and their language style (whether they used neutral or positive language). Because the previously discussed research has shown that positive language can have either positive or negative effects, no directional hypotheses were stated. Instead, the goal was to answer the following nondirectional research questions: (1) How does positive language, in comparison to neutral language, influence the trustworthiness of a person arguing in an online health forum and the credibility of their health claims; (2) How does working for a university, in comparison to working for a lobbying organization, influence the trustworthiness of a person arguing in an online health forum and the credibility of their health claims; and (3) Do the two factors of language style and professional affiliation interact with each other to influence trustworthiness and credibility judgments?
A 2 (language style: neutral language vs positive language) × 2 (professional affiliation: scientist vs lobbyist) between-subject experimental design was used, resulting in four experimental conditions. In each experimental condition, participants saw two online forum posts: a question post and an answer post. In the question post, a woman asked whether Batradicum was an effective drug for the treatment of attention deficit hyperactivity disorder (ADHD). The question post was written in a neutral language style and was the same in all four experimental conditions. In the answer post, a man introduced himself and argued that Batradicum is an effective drug for the treatment of ADHD. The experimental manipulations were realized in the answer post. Depending on the experimental condition, the answer post was written either in a neutral language style or a positive language style. Furthermore, the author of the answer post introduced himself either as a scientist who worked for a pharmacological institute at a university, or as a lobbyist who worked at a pharmacological lobbying organization.
As a note, the positive language style version of the answer post contained the words and phrases printed in italics, and the neutral language style version did not contain these words and phrases. For reasons of ecological validity, the name of an existing ADHD medication was used in the original study material. To avoid the impression that the authors endorse or criticize the drug, the fictitious drug name Batradicum is used here. Also, as the table shows an English translation of the German posts, the translated version may not appear as authentic to native English speakers as the original version appears to native German speakers. The original German version of the posts can be obtained from the authors upon request.
Dear forum community,
My son is, according to his teachers, hyperactive and cannot concentrate in class. Moreover, his grades are suffering and he might not be allowed to move up to the next grade. The doctor gave him an ADHD diagnosis and offered that he could prescribe him the drug Batradicum. Unfortunately, I am not an expert in this field and I have heard of different studies that either argue for or against the effectiveness of Batradicum.
Does anybody know more about this topic?
Thanks in advance!
Sabine Schneider
Hello Ms. Schneider,
My name is Johannes Becker and since I have been working for the [Scientist Manipulation:
You are right, in the past, many studies on Batradicum have contradicted each other, often because of methodological mistakes.
Recently, however, a
Yours sincerely,
Johannes Becker
German university students were contacted via email and social network sites and received €5 (US $5.65) for participating in the experiment. Overall, 251 participants completed the study without interruption, but 7 participants were excluded from data analysis because they indicated that they encountered technical problems during the study. Furthermore, 2 participants were excluded from data analysis because they indicated that they did not answer the questions honestly. The final sample contained 242 (165 females, 77 males) students (175 undergraduate students, 67 graduate students) at an average age of 23 years old (mean 22.57; SD 3.05). The average participant had been enrolled in their study program for five semesters (mean 4.81; SD 3.38). The experiment was conducted online using the EFS Survey platform (Questback GmbH, Cologne, Germany). First, participants gave informed consent, provided demographic information, and answered the control measures. They were then randomly assigned to one of the four experimental conditions. After reading the forum posts, participants answered the dependent measures and the manipulation check question. At the end of the experiment, the participants were debriefed.
A total of four control measures were included to assess whether the experimental groups differed in characteristics that could bias the study results. Participants answered three questions [General Use: “How often do you visit Internet forums?”; Educational Use: “How often do you visit Internet forums to learn something new or acquire new skills?”; Prior Knowledge: “How much do you know about Batradicum?”) and indicated their agreement with one statement (Prior Attitude: “Batradicum is an effective drug for the treatment of ADHD.”) on seven-point scales. To check whether the language style manipulation was successful, participants answered the question, “How would you describe Johannes Becker’s choice of words?” on a scale ranging from 1 (neutral) to 7 (extremely enthusiastic).
To assess the credibility of the provided information, two measures were used, one of which was a general credibility measure, the Message Credibility Scale [
For all analyses, the statistical software SPSS Statistics Version 26 (IBM Corp, Armonk, New York, United States) was used. Four one-way between-subject analyses of variance were conducted with experimental condition as the independent variable and the control measures as dependent variables. The results showed that the participants in the four experimental groups did not significantly differ in regard to the control measures of General Use (
For the analyses of the dependent measures, two-way between-subject analyses of variance were conducted with language style (neutral language vs positive language) and professional affiliation (scientist vs lobbyist) as independent variables.
There were significant main effects of language style on Message Credibility (
There were no main effects of professional affiliation on the dependent measures of Message Credibility (
The two factors of language style and professional affiliation did not interact with each other to influence trustworthiness and credibility judgements for Message Credibility (
As a note for
Main effects of the dependent measures by language style and professional affiliation.
Dependent measures | Language style | Professional affiliation | |||||||||||
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Neutral |
Positive |
Scientist |
Lobbyist |
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Message Credibility | 3.75 (1.19) | 3.24 (1.20) | .001 | 3.62 (1.25) | 3.36 (1.17) | .09 | ||||||
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Attitude | 3.80 (1.42) | 3.95 (1.22) | .38 | 3.96 (1.29) | 3.78 (1.36) | .29 | ||||||
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Machiavellianism | 4.18 (1.32) | 4.93 (1.29) | <.001 | 4.46 (1.46) | 4.64 (1.24) | .29 | ||||||
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Expertise | 4.45 (1.20) | 4.23 (1.14) | .15 | 4.39 (1.23) | 4.29 (1.12) | .53 | ||||||
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Integrity | 4.00 (1.17) | 3.51 (1.10) | .001 | 3.85 (1.14) | 3.68 (1.19) | .24 | ||||||
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Benevolence | 3.68 (1.20) | 3.31 (1.11) | .02 | 3.54 (1.20) | 3.45 (1.13) | .51 | ||||||
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Likability | 3.37 (0.97) | 3.22 (0.97) | .19 | 3.39 (0.96) | 3.19 (0.97) | .11 |
Dependent measures that were significantly influenced by language style.
The goal of the present study was to explore whether the language style (positive vs neutral) and professional affiliation (scientist vs lobbyist) of a person communicating health information in an online forum would influence their trustworthiness and the credibility of their health claims. The results show that if the forum post author used positive language in comparison to neutral language, they were perceived as less trustworthy, and their health claims were deemed less credible. More specifically, if the forum post author used positive language, they were perceived as more manipulative (Machiavellianism), less sincere (Integrity), less benevolent (Benevolence), and their health claims were perceived as less credible (Message Credibility).
In contrast, the professional affiliation of the forum post author (whether they were a scientist or a lobbyist), affected neither their trustworthiness nor the credibility of their information. This result is surprising because it contradicts previous findings [
Even though the results of the current study increase the understanding of how information seekers assess the accuracy of health information in online forums, there are limitations to the generalizability of the results. Four limitations seem especially important. First, the study participants were relatively young due to their status as students. Since previous research has found that age might influence source monitoring, suggestibility to misinformation [
Consequently, future research should explore the positive language style effect within the context of less controversial topics. Furthermore, previous research suggests that the impact of expert testimony is influenced by the congruency between the gender of the expert and the topic at hand [
When searching for health information, many people use the internet as their first source of information. When they are confronted with positive language in online health forums, indicated by the frequent use of positively valenced adjectives, they may judge the health communicator as less trustworthy and deem the communicated health claims as less credible. These findings illustrate that health information seekers do not just react to the factual part of health information. Instead, they use the language style that surrounds health claims to evaluate the credibility of the provided information and the trustworthiness of the information source.
attention deficit hyperactivity disorder
The authors would like to thank Dr Celeste Brennecka for language editing and their research assistant Hannah Meinert for her support. This work was supported by the German Research Foundation within the framework of the Research Training Group GRK 1712 Trust and Communication in a Digitized World. The funding was granted to the second author. The German Research Foundation had no involvement in study design, data collection, analysis and interpretation, and the decision to submit the study for publication.
LK and RJ contributed to the conceptualization of the study. LK contributed to the study design. LK was responsible for data acquisition. LK and RJ were responsible for analysis and interpretation of data. LK was responsible for drafting the manuscript. LK and RJ were responsible for revising the manuscript critically for important intellectual content. LK and RJ approved the revision of the manuscript to be published.
None declared.