In these times, when Donald Trump and Greta Thunberg are active, discussions on scientific findings can become emotional. But how does the general public see such emotional debates’ Initial answers to this question have now been found in the interdisciplinary DFG (German Research Foundation) Research Training Group “Trust and Communication in a Digitized World”. In two studies, Prof. Regina Jucks and I together examined the effects that aggression on the one hand, and enthusiasm on the other, have in science communication. The result: both styles of language can damage the trustworthiness of science communication and the credibility of its arguments.
Why are these findings especially relevant for scientists today?
When scientists report the latest findings from their research, this does not mean that their conclusions are automatically believed. Rather, discussions of these results then begin within the scientific community. Did the researchers select appropriate methods in their search for answers to the underlying questions’ Did they evaluate the research data in a statistically correct manner? Can the results be interpreted differently? This debate is important because it serves as a quality control mechanism within the scientific community. As a result, it is hardly surprising that such debates are held at scientific conferences and in the pages of scientific journals.
However, when scientific findings are relevant for a large number of people, these debates increasingly take place in public and they often centre on results that promise answers to specific, personal questions. Can I increase my life expectancy by drinking a glass of red wine every evening? Will I get colon cancer if I continue to eat processed meat? Can my cholesterol level be reduced if I give up eating an egg for breakfast? In particular, emotions run high when there is not yet any scientific consensus. One researcher argues her case enthusiastically, another presents his arguments against it in an aggressive manner.
In such a situation, how does the non-specialist decide which information he or she can rely on? It would be a fine thing if it were the quality of the arguments which is decisive. But this does not appear to be realistic in many cases. Often, arguments are based on highly complex scientific findings, the quality of which is difficult for non-specialists to form a judgement on. Is it possible that the non-specialist is swayed by the way in which an argument is presented? In other words: not what is said, but how it is said?
One aim of our studies was to discover the effects that aggression and enthusiasm have on the trustworthiness of scientists and the credibility of their arguments in scientific debates. For this purpose, 179 people acting as guinea pigs took part in a discussion on the effectiveness of anti-depressant drugs. Depending on the conditions applying in the experiment, a participant stated his case by using either an aggressive or a neutral style of speaking, with the arguments being identical in both cases. The result was that when the participant used an aggressive way of speaking, listeners found him to be less trustworthy and were not very receptive to his arguments.
But what is the result when the scientist uses an enthusiastic style of speaking instead of an aggressive one? With a view to investigating this question, 270 guinea pigs read texts from a health forum in which there was a discussion on the extent to which so-called deep-learning technologies can be used to diagnose illnesses. The structure of the experiment was similar to that of the first study. Depending on the conditions applying in the experiment, the author used either enthusiastic or neutral language to argue his case. The evaluation of the results showed that a use of enthusiastic language also harmed the author’s trustworthiness and made his arguments appear less credible.
So emotional language can harm the trustworthiness of scientists as well as the credibility of their arguments. How far these results can be generalized, and whether they are valid only for certain topics and cultures, are questions which will have to be addressed in future studies. Anyone wishing to participate in the current discussion on these issues is invited to read the recently published articles entitled “Hot topics in science communication: Aggressive language decreases trustworthiness and credibility in scientific debates” (DOI: 10.1177/0963662519833903) and “Influence of Enthusiastic Language on the Credibility of Health Information and the Trustworthiness of Science Communicators: Insights From a Between-Subject Web-Based Experiment” (DOI: 10.2196/13619).
This article first appeared in the University newspaper