COVID-19 health certification reduces outgroup bias: evidence from a conjoint experiment in Japan

Yoshiaki Kubo; Isamu Okada

doi:10.1057/s41599-022-01324-z

COVID-19 health certification reduces outgroup bias: evidence from a conjoint experiment in Japan

Humanit Soc Sci Commun. 2022;9(1):306. doi: 10.1057/s41599-022-01324-z. Epub 2022 Sep 9.

Authors

Yoshiaki Kubo^{1

2

3

4

5}, Isamu Okada⁶

Affiliations

¹ Department of Law, Politics, and International Relations, Faculty of Humanities and Social Sciences, University of the Ryukyus, Nishihara, Okinawa Japan.
² Research Institute for Humanity and Nature, Kyoto, Japan.
³ Department of East Asian Languages and Cultures, Hamilton Lugar School of Global and International Studies, Indiana University, Bloomington, IN USA.
⁴ Program on U.S.-Japan Relations, Weatherhead Center for International Affairs, Harvard University, Cambridge, MA USA.
⁵ Present Address: Department of Urban Studies, School of Policy Studies, Kwansei Gakuin University, Sanda, Hyogo Japan.
⁶ Department of International Development and Cooperation Studies, Graduate School of International Development, Nagoya University, Nagoya, Japan.

Abstract

The psychological theory argues that serious threats cause negative attitudes from ingroups to outgroups. However, the factors that can reduce such outgroup bias caused by the health threats of a pandemic are unknown. Here, we provide evidence that health certifications to prove immunity or negative test result for COVID-19 reduce outgroup bias. Using a discrete choice experiment with a randomized conjoint design in Japan, we investigated public attitudes towards inbound travelers entering the country, including foreigners, immigrants, and tourists. We found that travelers carrying a vaccination certificate or a negative test result for COVID-19 have a higher probability or rating of being admitted to the country. These effects are the same size as those for travelers undergoing self-isolation. Thus, our results demonstrate that health certification can mitigate outgroup bias among ingroup members experiencing threats to health due to the COVID-19 pandemic. We anticipate that the findings would support the combined usage of vaccine passports and negative certificates to reopen the international borders.

Keywords: Politics and international relations; Psychology; Science, technology and society.