Political ideology and environmentalism impair logical reasoning

Abstract

People are more likely to think statements are valid when they agree with them than when they do not. We conducted four studies analyzing the interference of self-reported ideologies with performance in a syllogistic reasoning task. Study 1 established the task paradigm and demonstrated that participants’ political ideology affects syllogistic reasoning for syllogisms with political content but not politically irrelevant syllogisms. The preregistered Study 2 replicated the effect and showed that incentivizing accuracy did not alleviate these differences. Study 3 revealed that syllogistic reasoning is affected by ideology in the presence and absence of such bonus payments for correctly judging the conclusions’ logical validity. In Study 4, we observed similar effects regarding a different ideological orientation: environmentalism. Again, monetary bonuses did not attenuate these effects. Taken together, the results of four studies highlight the harm of ideology regarding people’s logical reasoning.

Keywords:

• Political ideology
• logical reasoning
• motivated reasoning
• environmentalism
• monetary incentives

Acknowledgments

We thank Rebekka Henseler for her help in data collection and survey creation in Study 4.

Disclosure statement

No potential conflict of interest was reported by the authors.

Notes

1 Among the syllogisms, we added two attention check items (Oppenheimer et al., 2009). In these items, participants read two neutral premises, and the conclusion asked participants to respond in a certain way (mark incorrect/correct). However, we refrained from using them as exclusion criteria because the conclusion could also have been construed as not logically following its premises. Some attentive participants of Study 4 brought this forth as they marked both conclusions in contrast to its instruction but in line with the overall task instructions. Accounting for the attention check items does not change the pattern of results.

2 In Study 3, we clarified the instructions of the two attention check items (Oppenheimer et al., 2009). Specifically, participants read in between the other syllogisms: “This is not a syllogism. This is testing whether your responses are recorded correctly. Therefore, please respond with conclusion [in]correct.” Because only four participants missed at least one of the attention checks, we report the analysis with the whole sample in an intention-to-treat manner.

3 The significantly smaller proportion of participants who marked every conclusion as correct in Study 4 compared to Studies 1–3 may reflect an increased compliance in laboratory studies.

4 We included syllogisms with xenophobic conclusions and a measure of attitudes toward immigration as a proxy for endorsing the ideology of xenophobia. Though we expected university students to be anti-xenophobic, this combination would test whether the absence or rejection of an ideology produces similar results to endorsing an ideology when it comes to ideological reasoning performance. However, participants endorsed environmentalism to a more substantial degree than they rejected xenophobia. There were no subsequent effects of the attitudes toward immigration on ideological reasoning performance for xenophobic syllogisms. Descriptions of the attitude measure, the syllogisms, and the corresponding results are in the supplemental material, as is a discussion of the results.

Additional information

Funding

This work was supported by the Deutsche Forschungsgemeinschaft (DFG, [German Research Foundation]) under Grant 441551024 awarded to Lucas Keller and Peter M. Gollwitzer.