Quand la politique et la génétique se rencontrent : comment le public interprète-t-il la recherche?

The main objective of this doctoral thesis is to improve our understanding of how the public interprets scientific news about human genetics, specifically, behavioral genetics and the genetic underpinnings of racial groups. The core of the dissertation is a collection of three research articles and one book chapter. Chapter 1 introduces the readers to the goals and practices of science journalism, presents a summary of the literature on media effects, summarizes research on genopolitics, and discusses findings in public opinion on how people understand genetic influence on human characteristics. Chapter 2 presents the rationale behind the experimental method, explains its pros and cons, and provides examples of how different types of research designs have been used in political science. All the empirical evidence presented in this dissertation rests at least in part on experiments. Chapter 3 presents the results of a survey experiment that aims to measure the effects on individuals of reading a news article about behavioral genetics research. The study suggests that the public has difficulty in making sense of such research findings. The results show that participants tend to generalize the conclusions of one particular genetic study to other characteristics not mentioned by the study. I hypothesize that these results can be explained by a well-known and widely documented psychological process: the use of anchoring and adjustment heuristics. Chapter 4 presents the results of a second survey experiment. This experiment manipulates the content of a news article about behavioral genetics. The purpose of the manipulation is to test whether particular aspects of article’s message are more likely than others to cause the hasty generalizations revealed in Chapter 3. The findings show that the tendency to generalization is greater when the news presents high heritability estimates derived from twin studies or insights from research using population genetics methods to account for aggregate geographic difference. Based on these findings, the chapter develops recommendations for science journalists interested in covering behavioral genetics. Chapter 5 focuses on a different field of human genetic research, namely, that investigating the genetic bases of racial differences. The chapter’s aim is to improve our understanding of how the public reacts when exposed to scientific claims arguing against the idea that that human beings belong to different, genetically distinct races.  Both cross sectional survey data and experimental data suggest that conservatives and liberals react to this information in opposing ways. Liberals tend to accept such arguments and temper their beliefs that genetic differences account for racial inequalities. By contrast, conservatives reject the arguments so strongly that exposure to them actually strengthens these citizens’ beliefs that genetics explain a proportion of racial inequality. These results are interpreted from the perspective of motivated reasoning theory. Finally, Chapter 6 summarizes the main findings of the doctoral dissertation, highlights its contribution to the discipline of political science and the field of science communication, and suggests directions for future research.

Keyphrases: Science communication, Genopolitics, Media effects, Behavioral genetics, Genetics and race, Motivated reasoning, Heuristics, Genetic attribution