Hiraishi, Kai

写真a

Affiliation

Faculty of Letters, Department of Humanities and Social Science (Human Relations) ( Mita )

Position

Professor

E-mail Address

E-mail address

Related Websites

External Links
Scopus Paper Info  
Paper Count: 32 Citation Count: 705 h-index: 13

Click to view the Scopus page. The data was downloaded from Scopus API in May 31, 2026, via http://api.elsevier.com and http://www.scopus.com .

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Career 【 Display / hide 】

  • 2001.10
    -
    2004.03

    The University of Tokyo, Interfaculty Initiative in Information Studies, Research Associate

  • 2004.04
    -
    2004.09

    The University of Tokyo, Institute of Socio-Information and Communication Studies, Associate Researcher

  • 2004.10
    -
    2007.12

    The University of Tokyo, College of Arts and Scienes, Assistant Professor

  • 2008.01
    -
    2012.03

    Kyoto University, Kokoro Research Center, Program-Specific Assistant Professor

  • 2012.04
    -
    2014.03

    Yasuda Women's University, Department of Psychology, Lecturer

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Academic Degrees 【 Display / hide 】

  • 博士（学術）, The University of Tokyo, 2008.12

    An evolutionary psychological approach to sharing-rule reasoning and trust : General patterns and individual differences

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Research Areas 【 Display / hide 】

  • Humanities & Social Sciences / Social psychology

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Research Keywords 【 Display / hide 】

  • Prosociality

  • Cognitive Biases

  • Evolutionary Psychology

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Papers 【 Display / hide 】

  • A systematic review of conference papers presented at two large Japanese psychology conferences in 2013 and 2018: did Japanese social psychologists selectively report p < 0.05 results without peer review?

    Hiraishi K., Miura A., Higuchi M., Fujishima Y., Nakamura D., Suyama M.

    Peerj 12 2024

    　View Summary

    We conducted a systematic review of conference papers in social psychology at two large psychology conferences in Japan: the Japanese Psychological Association and the Japanese Society for Social Psychology. The conference papers were effectively not subjected to peer review; hence, they were suitable for testing if psychologists selectively reported statistically significant findings without pressure from journal editors and reviewers. We investigated the distributions of z-values converted from the p-values reported in the articles presented at the 2013 and 2018 conferences. The z-curve analyses suggest the existence of selective reporting by the authors in 2013. The expected discovery rate (EDR) was much lower than the observed discovery rate (ODR; 7% vs. 76%, respectively), and the 95% confidence interval (CI) did not include the ODR. However, this does not mean that the set of studies completely lacked evidential value. The expected replication rate (ERR) was 31%; this is significantly higher than 5%, which was expected under the null hypothesis of no effect. Changes were observed between 2013 and 2018. The ERR increased (31% to 44%), and the EDR almost doubled (7% to 13%). However, the estimation of the maximum false discovery rate (FDR; 68% in 2013 and 35% in 2018) suggested that a substantial proportion of the reported findings were false positives. Overall, while social psychologists in Japan engaged in selective reporting, this does not mean that the entire field was covered with false positives. In addition, slight signs of improvement were observed in how they reported their findings. Still, the evidential value of the target studies was weak, even in 2018, allowing for no optimism.

  • Differences in and associations between belief in just deserts and human rights restrictions over a 3-year period in five countries during the COVID-19 pandemic

    Murakami M., Hiraishi K., Yamagata M., Nakanishi D., Ortolani A., Mifune N., Li Y., Miura A.

    Peerj 11 2023

    　View Summary

    Discrimination, which arose during the coronavirus disease 2019 outbreak, is a global public health issue. This study aimed to provide fundamental knowledge in proposing control measures to mitigate discrimination. We focused on two psychological variables: belief in just deserts (BJD, i.e., the belief that the infected individual deserves to be infected), a psychological factor that potentially promotes discrimination and prejudice, and human rights restrictions (HRR; i.e., the degree of individuals’ agreement with government restrictions on citizens’ behavior during emergencies). Differences in these items, as well as their annual trends from 2020 to 2022, were examined in Japan, the United States (US), the United Kingdom (UK), Italy, and China. In addition, the associations between BJD and HRR by country and year and the direction of the associations between them in Japan and Italy were analyzed. Online surveys were conducted annually, with 392–518 participants per country and year. The BJD was higher in Japan and lower in the UK. BJD increased significantly from 2020 to 2021 in all countries, except in China. Meanwhile, HRR was higher in China and lower in Japan. The HRR decreased from 2020 to 2021 in Japan and decreased from 2020 to 2022 in the US, the UK, and Italy. There were significant positive associations between BJD and HRR in Japan and Italy. Cross-lagged panel models revealed positive bidirectional associations between BJD and HRR in Japan and Italy, respectively, indicating that the HRR declined among those with weak BJD and that the BJD increased among those with high HRR. In Japan and Italy, the dissemination of public messages targeting those with a high HRR in the early stages of an infectious disease outbreak could potentially mitigate the adverse impact of the BJD, eventually reducing discrimination, especially when the infection is not attributed to the fault of the infected individuals.

  • Belief in just deserts regarding individuals infected with COVID-19 in Japan and its associations with demographic factors and infection-related and socio-psychological characteristics: a cross-sectional study

    Murakami M., Hiraishi K., Yamagata M., Nakanishi D., Miura A.

    Peerj 10 2022.12

    　View Summary

    Prejudice related to the coronavirus disease 2019 (COVID-19) is a social issue worldwide. A possible psychological factor that promotes prejudice is the belief in just deserts (BJD) regarding individuals infected with COVID-19 (i.e., the belief that the infected individual deserves to be infected). The BJD is based on the belief in immanent justice. It is reportedly higher in Japan than in other countries. Therefore, we conducted a cross-sectional study to investigate the BJD among Japanese individuals and clarify its associations with demographic factors or infection-related and socio-psychological characteristics. To this end, we conducted an online questionnaire survey in Japan from August 7–8, 2020, with 1,207 respondents aged 20–69 years. We performed screening to exclude inappropriate responses. We investigated the association between the BJD and demographic factors such as gender and age. We also investigated the association between the BJD and infection-related and socio-psychological characteristics, including risk perception of COVID-19 infection and human rights restrictions (i.e., the degree of agreement with government restrictions on individuals’ behavior during emergencies). Among the surveyed items, human rights restrictions showed a strong association with BJD, followed by risk perception of COVID-19 infection. Men had a slightly higher BJD than women. Our study is significant in that it is the first to investigate the items associated with the BJD, thereby providing foundational information for revising individual perceptions of justice related to COVID-19 and solving prejudice-related issues.

  • How to Detect Altruists: Experiments Using a Zero-Acquaintance Video Presentation Paradigm

    Oda R., Tainaka T., Morishima K., Kanematsu N., Yamagata-Nakashima N., Hiraishi K.

    Journal of Nonverbal Behavior 45 ( 2 ) 261 - 279 2021.06

    ISSN  01915886

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    In this study, we investigated the cognitive processes and nonverbal cues used to detect altruism in three experiments based on a zero-acquaintance video presentation paradigm. Cognitive mechanisms of altruism detection are thought to have evolved in humans to prevent subtle cheating. Several studies have demonstrated that people can correctly estimate levels of altruism in others. In this study, we asked participants to distinguish altruists from non-altruists in video clips using the Faith game. Participants decided whether they could trust allocation of money to the targets who were videotaped while talking to the experimenter. In our first experiment, we asked the participants to play the Faith game under cognitive load. The accuracy of altruism detection was not reduced when participants simultaneously performed a cognitive task, suggesting that altruist detection is rapid and effortless. In the second experiment, we investigated the effects of affective status on the accuracy of altruism detection. Compared with participants in a positive mood, those in a negative mood were more hesitant to trust videotaped targets. However, the accuracy with which altruism levels were detected did not change when we manipulated participants’ moods. In the third experiment, we investigated the facial cues by which participants detected altruists. Participants could not detect altruists when the upper half of the target’s face was hidden, suggesting that judgment cues exist around the eyes. We also conducted a meta-analysis on the effect size in each experimental condition to verify the robustness of altruism detection ability.

  • Spread of Risk Information Through Microblogs: Twitter Users with More Mutual Connections Relay News That is More Dreadful1

    Komori M., Miura A., Matsumura N., Hiraishi K., Maeda K.

    Japanese Psychological Research 63 ( 1 ) 1 - 12 2021.01

    ISSN  00215368

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    In elucidating the spread of risk information through microblogging, it is important to understand the behaviors of numerous average users, in addition to the activities of authorities. We followed the transmission pathways of 10 actual widely spread tweets concerning several risk information topics, including natural disasters, nuclear disasters, and infectious diseases, and we identified the types of risk that affected retweeting by classifying each tweet based on Slovic's risk-perception model. Furthermore, we examined the types of users who did and did not retweet the information. Users with few connections in the form of followers (i.e., people who are following a user) or followees (people a user is following), or with a low ratio of mutual followers within their connections, had a tendency to retweet a large amount of risk information, regardless of the type of risk involved. On the other hand, users with a high ratio of mutual followers exhibited a greater tendency to retweet risk information when it was perceived as dreadful, though they did not retweet risk information much on the whole. These results suggest that there are two mechanisms by which risk information is spread within the Twitter network: information exchange and social sharing of personal reactions.

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Papers, etc., Registered in KOARA 【 Display / hide 】

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Presentations 【 Display / hide 】

  • Genetic overlapping among intelligence, educational attainment, occupational status, marriage, and having children: Japanese female twins

    Shikishima, Chizuru, Yamagata, Shinji, Hiraishi, Kai, Kijima, Nobuhiko, Ando, Juko

    BEHAVIOR GENETICS, 

    2013.11

  • Long-term genetic effects of working memory on cognition and personality in adolescence and adulthood: A 14-year longitudinal study of twins

    Ando, Juko, Shikishima, Chizuru, Kijima, Nobuhiko, Hiraishi, Kai, Takahashi, Yusuke, Yamagata, Shinji

    BEHAVIOR GENETICS, 

    2013.11

  • Genetics of decision making: A Japanese twin study using the Allais problem

    Shikishima, Chizuru, Hiraishi, Kai, Yamagata, Shinji, Ando, Juko, Okada, Mitsuhiro

    BEHAVIOR GENETICS, 

    2012.11

  • Whose happiness increases, and why? A longitudinal twin analysis over a decade-long interval

    Shikishima, Chizuru, Yamagata, Shinji, Hiraishi, Kai, Ando, Juko

    BEHAVIOR GENETICS, 

    2011.11

  • Heritability of cooperative behavior on a public goods game

    Hiraishi, Kai, Shikishima, Chizuru, Ando, Juko

    BEHAVIOR GENETICS, 

    2010.11

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Research Projects of Competitive Funds, etc. 【 Display / hide 】

  • Leveraging Large Language Models in Persuasion Research: Toward a New Quantitative Idiographic Approach

    2025.04
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    2029.03

    基盤研究(B), Principal investigator

  • Building the groundwork for social psychology: Meta-analyses of unpublished studies in Japan and direct replications

    2019.04
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    2024.03

    MEXT,JSPS, Grant-in-Aid for Scientific Research, Grant-in-Aid for Scientific Research (B), Principal investigator

  • コーディネーション問題は道徳を生むか：進化シミュレーションによる検証

    2016.04
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    2019.03

    MEXT,JSPS, Grant-in-Aid for Scientific Research, Grant-in-Aid for Challenging Exploratory Research, Principal investigator

  • Psychological basis of reputation damages: The two step hypothesis on risk perception and evaluative learning

    2016.04
    -
    2019.03

    MEXT,JSPS, Grant-in-Aid for Scientific Research, Grant-in-Aid for Scientific Research (B), Principal investigator

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Courses Taught 【 Display / hide 】

  • ADVANCED STUDY OF SOCIAL SCIENCE 2

    2026

  • RESEARCH METHODS FOR HUMAN SCIENCES 4A

    2026

  • EXPLORING HUMAN SCIENCES 1

    2026

  • INTENSIVE SEMINAR: HUMAN SCIENCES 4

    2026

  • INTRODUCTION OF PSYCHOLOGY

    2026

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