This study attempted to analyze disaster prevention activities in Kuroshio Town, Kochi Prefecture, from the “Days-After” perspective, which is an attitude and way of talking about a disaster that has not yet occurred as if it has already happened. Days-After refers to a way of thinking and talking about a disaster that has not yet occurred not as a probability, but as something that will definitely happen in the future. It is a viewpoint that sees the occurrence of disasters as inevitable, and may cause people to give up on trying to prevent disasters. However, this study found that the Days-After perspective, which views the occurrence of a disaster as a certainty, transformed the residents of Kuroshio Town, who started exhibiting positive attitudes toward disaster prevention. Specifically, disaster-prevention activities in the Kaisho district of Kuroshio Town, Kochi Prefecture, including paintings about tsunamis created by the residents of Kuroshio Town, were analyzed. As a result, it was found that although there were conflicts over the assumption that a huge tsunami will occur during the process of learning that a future Nankai Trough earthquake is inevitable, the residents reflected on their own lives and rediscovered the value of daily life through the disaster-prevention activities, and imagined a future in which they survived the disaster.

We examined the impact of instructors’ beliefs about ability on their advice to underachieving learners. Two scenario experiments wherein participants were asked to advise an underachieving student as a teacher were conducted with different samples. When the student made sufficient effort, participants endorsing stronger entity beliefs (“Ability is fixed”) tended to attribute failure to a lack of ability and therefore encourage the student to change subjects. However, they tended to advise students to continue working on the same subject when the effort was insufficient. The results indicate that those endorsing stronger entity beliefs assess learners’ aptitude by observing their effort. Meanwhile, participants endorsing stronger incremental beliefs (“Ability is malleable”) were less likely to encourage students to change subjects regardless of the amount of effort, suggesting that they perceive it as a source of self-improvement. However, they showed a similar inferential process about learners’ ability as participants endorsing stronger entity beliefs, suggesting that they may also consider the informational aspect of the effort, although the indirect effect was weaker.

The act of sending mobile e-mail and LINE messages can be regarded as a form of social exchange. Therefore, assuming a general duty to reply as soon as possible exists, if a user perceives an imbalance between themself and a partner, they may adjust the speed with which they replies to their partner’s messages as a way of signaling their intentions toward the partner. Hence, even when users reply quickly when interacting with rapidly-replying partners, it is expected that they will impose a degree of balance when interacting with slow partners (the reciprocity hypothesis). This hypothesis was tested with respect to mobile e-mail and LINE messaging using surveys. We found a high correlation between reply speed and the number of characters exchanged between participants and their partners. We also found that participants’ reply speed depended on the speed of their partners’ own replies.

This study aims to clarify how the sentiment toward disaster volunteers changed before and after the COVID-19 pandemic and examine the social structure underlying this change. An increase in the exclusion of social minorities was noted during the pandemic. Such exclusion occurs when the boundary between out-groups and in-groups becomes apparent. This study analysed how such exclusionary discourse changed before and after the COVID-19 pandemic. We focused on Twitter discourse toward disaster volunteers in Japan before and after the pandemic. The results showed that tweets expressing anger significantly increased during a heavy rain disaster in 2020, while those expressing anxiety increased considerably after the pandemic. The proportion of negative tweets about disaster volunteers was also found to have increased after the pandemic. Furthermore, a content analysis of the tweets suggested that the negative tweets about disaster volunteers during the pandemic were more likely to include a clear distinction between those living within or outside of the affected prefecture than between those who are infected or uninfected. This study reveals that, in the case of the COVID-19 pandemic, the exclusionary discourse toward disaster volunteers draws a clear boundary between “insider” and “outsider.”

Japanese society was notable for responding to the COVID-19 pandemic by exercising ji-shuku, or self-discipline. In this paper, we argue that, as implied by phrases such as “self-discipline mood,” this form of self-discipline appears to be a phenomenon in which people act, on the one hand, voluntarily according to their own will and, on the other hand, in response to coercion from others. In other words, exercising self-discipline is an act that mixes dependence and independence in an ambivalent manner. However, this mixture is not a unique phenomenon observed only in the exceptional case of self-discipline. Indeed, there is a specific background—a “mild individualism”—in contemporary Japanese society that makes it tempting to adopt this particular style of self-discipline. The dominance of this style in Japanese society is supported by the fact that, apart from the self-discipline exercised during the COVID-19 pandemic, a great deal of social attention has been paid to concepts such as “middle voice” and “nudges.”

Infectious disease threats cause prejudice toward foreigners through the behavioral immune system. Huang et al. (2011) showed that vaccination can reduce such prejudice. This study investigated the effects of COVID-19 vaccination on attitudes toward foreign residents in Japan. A survey was conducted in two phases. Before the vaccination of older adults had begun, a survey measuring their attitudes toward foreigners was conducted as a baseline. Once the vaccination program was underway, a second survey was conducted to measure individual differences in germ aversion, vaccination status, perceptions regarding vaccine efficacy, and attitudes toward foreign residents. The survey (n=520) demonstrated that among the participants that were not fully vaccinated those with high germ aversion had more negative attitudes toward foreign residents than those with low germ aversion, which was consistent with the concept of the behavioral immune system. In contrast, germ aversion was attenuated among those who had been fully vaccinated. This effect occurred when the coronavirus vaccines were perceived to be highly effective. We discuss the ability of vaccination to reduce prejudice during the COVID-19 pandemic.

The COVID-19 pandemic has provided an opportunity to examine the relationship between the Behavioral Immune System (BIS) and disease avoidance behaviors and attitudes. In this study, we conducted an online survey to determine if, as predicted by the BIS, the threat of contracting COVID-19 elicits infection avoidance responses among young people who are critical to the spread of the disease. A total of 470 Japanese students from a metropolitan Tokyo university participated in the online survey from July 5–21, 2021; among these, 456 valid responses were analyzed, excluding responses from those who had been infected or were undergoing testing at that time (n=13). Contrary to our predictions, our data revealed that participants who knew people infected with COVID-19 in their close social network (n=152) were less enthusiastic about infection prevention responses than those who did not have infected acquaintances (n=304). The results suggest that young people may willingly trade off the risk of pathogen exposure against the benefits of maintaining social relationships.

The authors examined the effects of the interpersonal environment, including parents, friends, teachers, and neighbors, on longitudinal changes in the antisocial tendencies of youths, using before-and-after surveys conducted during the period of social restrictions against the COVID-19 pandemic. One thousand and ninety-eight grade students from grades four through nine were surveyed before and after the social restrictions in three waves. Their interpersonal environments were assessed by examining parenting, domestic violence, friendship, teacher’s leadership, and neighbors’ collective efficacy. Antisocial tendencies were measured by examining low self-control, callous-unemotional traits, moral disengagement, self-serving cognitive distortion, and normative beliefs about aggression. Latent profile analysis revealed four interpersonal environment profiles. Analysis of variance was used to compare longitudinal changes in antisocial tendencies among the four profiles. In class 2 (characterized by high parental control), the subjects’ self-control increased. Conversely, in classes 1 and 4 (characterized by adaptive environments), the subjects’ self-control decreased. In class 1, the score of callous unemotional traits increased. This was construed as indicating that the subjects’ opportunities to express empathy were decreased by the restrictions placed on their rich environments. Antisocial cognition indices indicated that the scores of selective moral disengagement, self-serving cognitive distortion, and normative beliefs about aggression decreased. This was construed as indicating that the opportunities these subjects had to learn cognitive biases were decreased by the restrictions placed on their social interactions.

Faced with the COVID-19 pandemic, some people in Japan have started voluntarily and anonymously policing others who do not engage in infection prevention behaviors. Such extreme ways of enforcing norms to prevent the spread of COVID-19 may have serious consequences since the targets essentially become victims of kangaroo courts. This study examined the possibility that such aggressive behavior is based on strong reciprocity, which is one of the proposed mechanisms that may have made humans super-cooperative. An online survey measured several aspects of strong reciprocity (e.g., altruistic punishment, altruistic rewarding), impressions of and behavioral intentions toward those who violate infection prevention norms and COVID-19 patients, and the degree to which the respondents engaged in infection prevention behaviors. The results revealed that the tendency to engage in altruistic punishment had a positive effect on aggression toward those who violated infection prevention norms and COVID-19 patients only among those who engaged in infection prevention behaviors. This suggests that altruistic punishment may promote aggression toward those who violate infection prevention norms in people who follow such norms.

There are many conspiracy theories about the novel coronavirus disease (COVID-19). Belief in these conspiracy theories may lead people to underestimate the risk of COVID-19 and adopt behaviors that increase their risk of infection. Consequently, they may not support national infection prevention policies. In study 1, we administered a survey in January 2021 and analyzed the data using structural equation modeling (SEM). The results revealed the validity of the following hypothesized model: “Conspiracy beliefs about COVID-19 → disregard for infection risk → individual behavior that increases infection risk and disapproval of national infection prevention policies.” In study 2, a longitudinal survey was disseminated to the respondents of study 1 in January 2022. The results were similar to those obtained with SEM in study 1. Analysis of the longitudinal data based on simultaneous effects and cross-lagged models revealed the following causal relationship: “Conspiracy beliefs about COVID-19 → underestimation of infection risk → infection prevention”. These results suggest that conspiracy beliefs about COVID-19 may have a disruptive effect on governments’ infectious disease control policies.

We conducted an exploratory Internet survey to examine the association among the amount of risk-related knowledge, risk perception, and preventive behavior observed during the early stages of the spread of the COVID-19 pandemic. We determined whether factors influencing risk perception and preventive behavior function as well in the case of COVID-19 as they do for other hazards. Knowledge was measured using subjective estimation and objective measurement via a quiz. To assess risk perception, we asked participants about the physical health risk to various targets (such as themselves, their families, the elderly, children, and the general population). Additionally, they were asked about the risk of social problems associated with the pandemic (including physical health concerns associated with self-restraint, mental health, environment, economy, sovereignty, and discrimination). The results showed that participants’ interest in COVID-19 was generally high; however, detailed knowledge about the incubation period, infection, and intensive contact was lacking. Interest was most significantly associated with perceived risk, followed by subjective knowledge, objective knowledge, and government trust. Based on the factor analysis results, preventive behaviors were categorized as: restrictions on going out and health care, coughing and handwashing precautions, and stockpiling. Overall, interest, subjective knowledge, government trust, and public perception of infection risk promoted preventive behaviors, while higher economic risk perception inhibited preventive behaviors.

This study investigated the intensity of people’s malicious and benign envy, pulling-down motivation, and travel intention upon knowing of others’ past or future travel during the COVID-19 pandemic. Participants read a scenario in which they found out that their friend either traveled or is going to travel. To manipulate the presence or absence of a travel plan, the scenario for half of the participants involved planning to travel themselves but the plan was canceled. The participants read the scenario and assessed their intensity of envy, pulling-down motivation, and travel intention. They then reported the extent to which they have stayed at home and avoided going outside since the COVID-19 pandemic. Results showed that for participants who stayed home and had their travel plans canceled, their friends’ past travel events led to stronger motivation to pull them down and a heightened intention to engage in gorgeous travel via malicious envy than their friends’ future travel activities. This suggests that people experience stronger malicious envy toward others’ past activities if the uncertainty of future events is high.

This study examined the changes in couples’ interdependence owing to the COVID-19 pandemic. The analysis included 289 couples who responded to a seven-wave longitudinal survey between February 2017 and October 2020. The results of the spline growth model analysis revealed that relationship satisfaction and approach commitment decreased for both partners before the COVID-19 pandemic. However, wives showed an increasing trend after the COVID-19 pandemic, while husbands did not change. Additionally, avoidance commitment increased in both partners before the COVID-19 pandemic, which further increased after the pandemic. Although this study examined the association between the post-COVID-19 slope, household income, and increased time at home, no association was found between them. Therefore, the results suggest that the COVID-19 pandemic provided an opportunity for couples to increase their interdependence, regardless of their income or life changes caused by the COVID-19 pandemic.

Humans tend to distort past events, leading to a gap between experience and retrospective experience—the retrospective bias. This study clarified the characteristics of retrospective bias in the ongoing COVID-19 pandemic. Longitudinal data from 597 Japanese individuals were gathered during the COVID-19 pandemic from January 2020 to January 2021. Analysis revealed that cognition regarding COVID-19 one year ago was retrospectively underestimated. In addition, within-person variation among the responses of the 11 waves consistently showed a negative association with bias. These findings suggest that retrospective methods of describing long-lasting and fluctuating events will lead to inaccurate conclusions.