Fukushima Daiichi: Each standard deviation increase in the influx of temporarily relocated survivors within 100 m of a resident’s home address was associated with a decrease in their trust in both people from their community and outside of it

Evaluation of Trust Within a Community After Survivor Relocation Following the Great East Japan Earthquake and Tsunami. Krisztina Gero et al. JAMA Netw Open. 2020;3(11):e2021166. doi:10.1001/jamanetworkopen.2020.21166

Key Points

Question  How is the movement of internally displaced survivors in the aftermath of a disaster associated with perceived trust towards others within a host community?

Findings  In this cohort study that included 3250 adults aged 65 years or older, each standard deviation increase in the influx of temporarily relocated survivors within 100 m of a resident’s home address was associated with a decrease in their trust in both people from their community and outside of it.

Meaning  The findings of this study suggest that opportunities for social interaction between old and new residents of host communities may be crucial for maintaining social trust.

Abstract

Importance  Trust is a core component of social cohesion, facilitating cooperation and collective action in the face of adversity and enabling survivors to remain resilient. Residential stability is an important prerequisite of developing trusting relations among community members. However, little is known about whether the movement of internally displaced persons (IDPs) after a disaster might change community relations.

Objective  We explored perceived changes in trust within 1 community directly impacted by the 2011 Great East Japan Earthquake and Tsunami.

Design, Setting, and Participants  This prospective cohort study examined survey data from 3594 residents of Iwanuma City, Japan, aged 65 years or older. Data were obtained from the Iwanuma Study—part of the Japan Gerontological Evaluation Study, a nationwide cohort study established in 2010—approximately 7 months before the disaster. All Iwanuma City residents age 65 years or older (8576 residents) were eligible to participate in 2010. The response rate was 59.0% (5058 residents). A follow-up survey was conducted in 2013, approximately 2.5 years after the disaster. Of the 4380 remaining participants who answered the baseline survey, 3594 were recontacted (follow-up rate, 82.1%). Data analysis was performed from July 1, 2019, to January 9, 2020.

Exposures  The number of temporarily relocated Iwanuma City survivors within 100 m and 250 m of a nonrelocated resident’s home address.

Main Outcomes and Measures  Perceived changes in particularized trust (ie, trusting people from the same community) and generalized trust (trusting people from other communities) measured on a 5-point Likert scale.

Results  Among 3250 nonrelocated residents (1808 [55.6%] women; mean [SD] age, 76.5 [6.2] years) of Iwanuma City included in the analytic sample, multivariable-adjusted multinomial logistic regression analyses found that each standard deviation increase in the influx of internally displaced persons (1 SD = 11 IDPs) within 250 m of a resident’s home address was associated with higher odds of a decrease in the resident’s particularized and generalized trust (odds ratio, 1.17; 95% CI, 1.04-1.32).

Conclusions and Relevance  The influx of IDPs in the host community appeared to be associated with an erosion of trust among locals. To avoid the erosion of social cohesion after a disaster, it may be crucial to provide opportunities for social interaction between old and new residents of communities.

Discussion

Our study found that after the 2011 Tohoku Earthquake, the influx of IDPs to another community was associated with weakening of both generalized and local trust, suggesting that the concentration of IDPs within a temporary shelter village (as happened in Iwanuma) may have a particularly detrimental effect on social cohesion.

Building trust between residents of a community depends on repeated social interactions over an extended period of time, whereas exposure to outsiders or out-groups can trigger conflict and mistrust.²⁰ In a 2007 study, Putnam²⁶ found that the influx of immigrants in communities can spur perceived competition over scarce resources (eg, housing, schools), ultimately resulting in reduced community cooperation and altruism, as well as lower trust not only in people perceived as different, but also in those who are perceived as similar. This study found that internal forced migration after a disaster, even within the same city from 1 district to another, might also lead to the erosion of the trust of nonrelocated residents in people from other communities as well as in people from the same community.

Previously, we reported that relocating IDPs together as a group, as opposed to randomly housing them throughout the community, can be an effective means of preserving social connections and strengthening the resilience of disaster survivors.¹⁰ However, the same policy may also inadvertently promote erosion of trust between older residents of the host community and newcomers.

We have therefore identified a potential dilemma in postdisaster resettlement. Our previous studies^10,27,28 have reported that the resettlement of survivors needs to take into account the preexisting social ties within a disaster-effected community in order to prevent the loss of communality associated with widespread housing destruction. In Iwanuma, the city offered 2 different means of relocation to temporary housing to survivors. People could choose between individual relocation—moving to public housing by a random lottery or seeking housing in the open rental market—or group relocation, in which whole communities would be moved together as a group into prefabricated temporary housing villages (resembling FEMA-style trailer parks in the US). Families who wanted to escape the emergency shelters as soon as possible selected the individual option, so they could leave the shelters as soon as their number came up on the lottery. However, this mode of resettlement had the unintended consequence of disrupting existing social connections in the community and scattering the residents randomly throughout the trailer settlement. We previously found that people selecting the lottery option reported lower levels of social participation and social support.^10,28 By contrast, people selecting group resettlement were even more likely to be engaged in informal social participation 3 years after the disaster compared with before the disaster.¹⁰ However, as the result of our present analysis suggests, the option of moving large numbers of IDPs together and concentrating them into 1 location may lead to greater friction with established residents of host communities.

Limitations

Several limitations need to be considered while interpreting the findings of this study. First, although we controlled for socioeconomic status, depressive symptoms, and personal disaster experiences, there may be residual confounders that we failed to take into account. Second, the number of nonrelocated participants reporting much weaker trust after the earthquake is quite small (12 participants), resulting in relatively wide 95% CIs around the point estimates. Therefore, the results have to be interpreted with caution. Third, because of the uneven distribution of displaced survivors in the community, we were unable to determine the precise threshold between 8 and 21 IDPs when the erosion of trust began to occur. The results suggest that the resettlement of a few scattered individuals in a community was not associated with changes in on local trust. The erosion of trust seemed to appear when larger numbers of people moved in. Fourth, we do not have information on the residential movements of people younger than 65 years, which might not be correlated with the movement of people aged 65 years or older. On the other hand, two-thirds of the population of the city of Iwanuma were aged 65 years or older before the disaster, and the age structure of IDPs was similar. Fifth, it is not clear how participants define people from their community and people from other communities. By 2013, when the question was asked, IDPs had spent approximately 2.5 years in their new environment. Thus, the respondents may have perceived the displaced population as either people from their own community or as outsiders. Hence, the 2 questions about trust might not have distinguished between particularized and generalized trust, which would also explain the similarity of the corresponding OR estimates. Also, perceived change in trust was measured based on 1 question instead of a multi-item scale, which hindered a more precise assessment of trust levels among the respondents. Sixth, the question of the generalizability of our results needs to be considered due to the relatively low response rate (59%) on the baseline survey. However, previous reports based on the JAGES study confirmed that the demographic profile of the participants is similar to the rest of the residents aged 65 years or more in Iwanuma City.^7,10 Moreover, a 59% response rate is comparable with other studies on community-dwelling respondents.²⁹