Social distancing between personal belongings during the COVID-19 pandemic

Introduction

Social psychology and proxemics have long addressed personal space as the spatial range surrounding the individual (Sommer, 1959; Hall, 1966). The space around the individual may exist in two forms. One is interpersonal distance, the area around the body that individuals maintain between themselves and others during social interactions (Candini et al., 2021). The other one is peripersonal space, which is an adaptive and flexible interface between the body and the environment, contributing to the organization of social life. For example, when this space is encroached by others, we may feel uncomfortable, or may prepare our bodies for defensive responses (Hall, 1966; Coello and Cartaud, 2021). In our study, the concept of ‘personal space,’ as referenced later, aligns more closely with the notion of peripersonal space. This refers to the space immediately surrounding the body, within reach, centered on the individual, and typically protected from intrusion during social interactions.

However, the center of personal space is oneself, but it is not restricted to the physical body; much evidence proposed that the concept of self is expanding in space and timeline. For example, the ‘cutaneous rabbit’ can be felt not only on one’s body but also on an object that one is grasping (Miyazaki et al., 2010). The line of sight away from the eye can still be perceived as exerting force on the object (Guterstam et al., 2019). Furthermore, the extension of body representations to objects has been observed in neuroscience (Iriki et al., 1996). As a result, personal space boundaries also expand with the extension of body perception.

One observed phenomenon is in some school situations where there are desk-mates; after an argument, desk-mates will avoid putting their stationery close to the other’s belongings. It is possible that people develop a tendency to recognize personal belonging as a representation of the self at an early age (Pedersen, 1973). According to James (1890), the self is the sum of all that he can call his, including all possessions, which gives him the same emotions. Briefly, we regard our possessions as part of ourselves. This intrinsic association between personal belongings and the self-forms the foundation for understanding how external objects, including tools and technologies, can become integrated into one’s sense of self, extending the boundaries of personal space. Studies on body ownership illusions suggest that the integration of external objects or virtual representations into one’s sense of self occurs through multisensory signals, highlighting the neural mechanisms underlying extended personal space (Nilsson & Kalckert, 2021). Is this sense of ownership of objects related to personal space? Ariga (2016) reported that participants placed their own objects at a greater distance from the objects of those who were unfavorable. These findings suggest that individuals’ personal space extended to the space surrounding their belongings (i.e., extended personal space). The placement of such personal belongings can be considered the most significant evidence of an extension of personal space, as it shares the same characteristics with personal space (Russell & Ward, 1982; Becker, 1973), that the variability depending on the level of familiarity with others. Moreover, recent studies have shown that object ownership influences the representation of peripersonal space. Specifically, self-owned objects within the peripersonal space are processed faster and perceived as more reachable compared to objects owned by others, suggesting an extension of peripersonal space representation around self belongings (Lenglart et al., 2023). This effect is particularly pronounced in individuals with higher interpersonal sensitivity, as their peripersonal space boundaries dynamically adapt in response to social contexts. Further supporting this perspective, Rabellino et al. (2020) highlight that peripersonal space is not only critical for physical interactions with the environment but also closely tied to bodily self-consciousness. They suggest that peripersonal space representation involves multisensory processing and serves both protective and social functions, allowing individuals to dynamically adjust to interactions with others. These findings further support the idea that ownership can extend personal space to include the area surrounding one’s possessions, reinforcing the concept of “extended personal space.”

The COVID-19 pandemic has persisted for more than three years. Governments and experts have provided instructions and suggestions to maintain a certain social (physical) distance between people to prevent droplet and aerosol infection of the virus (Yonemitsu et al., 2020; Yang et al., 2021), and this is now becoming the norm (Yamada et al., 2021). Along with the research development, we know that aerosol is one of the transmission routes (Anderson et al., 2020). Coronaviruses can be released into the surrounding air and exist for an extended period for long-distance transportation (Jiang et al., 2021), which means that exposed people and objects may carry the coronavirus present in aerosols. Van Doremalen et al. (2020) compared the survivability of SARS-CoV-2 (leading to COVID-19) and SARS-CoV-1 on different surfaces. They found that the survival time of SARS-CoV-2 on different material surfaces ranged from a few hours to a few days; suggesting that the surface of an item can be one of the potential pathways for virus transmission. Centers for Disease Control and Prevention (CDC) Guidelines and the World Health Organization (WHO), in their information on COVID-19, also mentioned that the virus can be transmitted by direct contact with contaminated surfaces.

Regardless of the purpose or function of a place, the dense gathering of many people must be avoided. Is it possible to receive such health guidance consistently and imperceptibly influence people’s social cognitive behavior? Recent studies have reported that interpersonal distance (IPD) increased during the COVID-19 pandemic (Holt et al., 2022; Iachini et al., 2021), and enlarged IPD preferences were predicted to persist beyond the pandemic (Welsch et al., 2021). However, it is important to note that the enlargement of IPD is not a universal phenomenon. As Iachini et al. (2021) observed, IPD increases only when subjective risk levels are high. Similarly, Givon-Benjio et al. (2024) demonstrated that subjective risk, rather than actual infection risk, predicted changes in preferred IPD. Cartaud et al. (2020) further supported this by showing that even under conditions of high actual risk, individuals’ preferred IPD remained unchanged unless subjective risk was elevated. The results of an experiment in Arabia revealed that in the post-epidemic era, 76% of the participants were already subjectively reluctant to share close physical distance or socially polite touch with others (Khan et al., 2021). Responding to precautions, the external manifestation is that we have actively increased our physical distance, but in reality, personal space has also expanded accordingly. In several studies related to personal distance in COVID-19, Fini et al. (2021) showed that interpersonal distance is influenced by the perception of realistic threat measured through the COVID-19 threat. In addition, previous research proposed that not only the perception of infection will make the public practice social distancing, but the behavior of practicing social distancing is related to specific individuals as well as related to the social meaning of collective health (Fazio et al., 2021).

How has the COVID-19 pandemic and countermeasures against it changed human-human and human-object interactions? Considering the findings of Ariga (2016), one’s personal space extends to his/her belongings, leaving them with an ‘extended personal space’. The present study aimed to examine if the ‘extended personal space’ increased as well as the personal space that has been affected under the pandemic of COVID-19. The fear of infection during the COVID-19 pandemic is closely associated with interpersonal distance. Research indicates that this fear is linked to a tendency to prefer greater interpersonal distance and to underestimate interpersonal space. However, these tendencies stem from subjective perceptions of risk rather than an actual objective risk of infection (Givon-Benjio et al., 2024). On the other hand, personal belongings are more closely related to peripersonal distance. For instance, Lenglart et al. (2023) found that individuals perceive personal items as being more “within reach” compared to other objects, suggesting an expansion in the representation of peripersonal distance. Based on the Coello and Cartaud, they indicated that interpersonal and peripersonal distances are interlinked and together influence social behavior. Therefore, in this study, we innovatively combine these two concepts for the first time to explore the impact of the combination of these two forms of personal space on social actions.

We initially tried to confirm that extended personal space would be larger during the COVID-19 pandemic than during pre-pandemic (i.e., before the pandemic). Maintaining a social (physical) distance from each other is valid for preventing viral infection by droplets and aerosols. Such avoidance of a close distance from other people over a long period modulates personal space (Tootell et al., 2021; Welsch et al., 2021). Thus, if it is true that space surrounding one’s belongings is based on the interpersonal relationship of their owner (Ariga, 2016), we predicted that extended personal space would be larger at the present time than at pre-pandemic (i.e., comparing extended personal space in the present time with that in Ariga’s study).

Methods

Procedure

The experimental setup is shown in Figure 1. A participant entered the waiting room, where the confederate was already present, and sat next to the confederate’s chair. The distance between two chairs was roughly 30-40 cm. In the friendly condition, the confederate started to talk about the weather with the participant and then tried to continue chatting freely. However, in the unfriendly condition, the confederate ignored the participant’s conversation and sighed every 15 seconds. Then, in both conditions, the experimenter instructed the participant and the confederate to place their belongings on the table and leave the waiting room to the experimental room. The confederate put his belongings in first and then left the room. The experimenter measured the shortest distance between the two belongings and took pictures. Distance was used as the dependent variable: If both belongings were in contact, the distance was coded as 0. In the experimental room, the participants completed a fake task and a rating task of favorability for the other participant (i.e., confederate). After the experiment was completed, we asked the participants two questions: ‘Do you realize our manipulation of favorability for the confederate?’ and ‘Why did you put the belongings there?’

Figure 1. Experimental setting.

Note. Left panel: A typical positioning of the belongings is depicted. In the experiment, the confederate and participant placed their personal belongings on the table sequentially (first, the confederate placed their backpack on the right side of the table every time). The experimenter measured the minimum distance between the two belongings (accurate to millimeters). Right panel: schematic representation of the experimental room. Two chairs were set up next to the room door: first, the confederate would sit on chair B and then, the participant was asked to sit on chair A, after entering the room. The table (W 60 cm × H 150 cm) for placing their belongings was facing the chairs. The width of the confederate’s belongings was about 36cm. The confederates were three graduate male students who took turns according to their schedules. Their average age was 23.6 years old (the confederate in the original experiment was a 21-years-old male).

Results

A total of 68 participants, 34 in the unfriendly condition (male = 17, female = 17, M = 20.83, SD = 2.22) and 34 in the friendly condition (male = 17, female = 17, M = 20.97, SD = 2.23), participated in the present study.

Confirmatory analysis

As pre-registered, we calculated the mean distance between the nearest edges of belongings ( Figure 2). Welch’s unpaired t-test showed that the mean distance was significantly longer in the pandemic condition (M = 43.6, SD = 25.0) than in the pre-pandemic condition (Ariga, 2016; M = 20.6, SD = 15.6) (t(105.63) = 5.88, p < .001, d = 1.10). The results suggest that people place their belongings further away from others in the COVID-19 era, supporting our hypothesis.

Figure 2. Violin plots and boxplots for the mean distance between belongings (pre-pandemic vs. pandemic).

Note. Red circles show mean values.

Exploratory analysis

Next, to check whether our manipulation was successful, we calculated the mean favorability for each condition (friendly and unfriendly). Welch’s unpaired t-test showed that the friendly condition (M = 8.21, SD = 1.43) had a significantly higher mean favorability than the unfriendly condition (M = 5.15, SD = 1.52) (t(65.76) = 8.54, p < .001, d = 2.07). These results suggest that the experimental manipulation was effective.

In addition, we conducted an exploratory two-way between-participants ANOVA with the confederate (friendly vs. unfriendly) and experimental timing (pre-pandemic vs. pandemic) as between-participants factors on the distance between belongings ( Figure 3). The results showed a significant main effect of the experimental timing (F(1, 104) = 27.39, p < .001, ${\eta }_G^2$ = 0.21). However, neither a significant main effect of the confederate (F(1, 104) = 1.66, p = .20, ${\eta }_G^2$ = 0.02) nor an interaction (F(1, 104) = 0.85, p = .36, ${\eta }_G^2$ = 0.01) were found. These results suggest that people place more distance between their belongings and others’ in the COVID-19 era, regardless of whether the other participant (i.e., confederate) was friendly.

Figure 3. Violin plots and boxplots for the mean distance between belongings (experimental timing × confederate).

Note. Red circles show mean values.

Discussion

This study aimed to investigate whether the distance between personal belongings changed during the COVID-19 pandemic. We directly replicated the experiment on the phenomenon in which distance was governed by the interpersonal relationship between owners, called extended personal space (Ariga, 2016), and explored the effect of COVID-19 on this phenomenon. Compared with the results for pre-pandemic from Ariga (2016), the gross distance between personal belongings during the pandemic was significantly longer. The results suggest that our pre-registered hypothesis was supported; extended personal space increased during period of the COVID-19 pandemic, but we consider COVID-19 as one of the reasons for this change. The large effect size of the difference implies that the psychological framework for processing people’s own belongings changed dramatically during this pandemic.

In this study, the procedure was directly repeated from the original experiment; the participants were Japanese university students, as in Ariga (2016), which ensured that the significant increase in distance was not due to inherent differences in personal space based on ethnicity (Hall, 1966) or age (Fry and Willis, 1971). The two experiments differed in period (pre-pandemic vs. pandemic). Participants in this study were university students who were under the COVID-19 pandemic during their university years; they were required to maintain social distance and avoid unnecessary outings. Maintaining social distancing means reducing or minimizing human interactions (Wilder-Smith and Freedman, 2020). Several studies have confirmed the increase in personal space during the COVID-19 pandemic and suggested the practice of social distancing attributed to the increase (Fini, Tummolini, and Borghi, 2021; Fazio et al., 2021). Moreover, our study found that the distance between objects increased during the pandemic. Recent findings from studies on the psychological impact of the COVID-19 pandemic provide additional support for our findings. For example, Serino et al. (2021) demonstrated that the pandemic led to a sharpening of peripersonal space boundaries, with individuals adapting their spatial perceptions in response to increased health-related concerns. This phenomenon aligns with our observation that the distance between personal belongings increased during the pandemic. The findings suggest that participants might have subconsciously extended their spatial boundaries to maintain greater safety and reduce perceived risks associated with potential contamination. This adaptation, as highlighted by Serino et al. (2021), may explain why people positioned their belongings farther away from other’s during the pandemic. Considering Ariga (2016), personal belongings have the same personal space-like properties as the owner, belongings also maintain their social distance when they are placed. This distance could manifest in the elongated distance of personal belongings.

One possibility is that the participants recognized the confederate and their belonging as carriers of an infectious disease. In Japan, perceived vulnerability to disease (PVD) has increased during the COVID-19 pandemic compared to pre-pandemic era (Yonemitsu et al., 2020), and the perceived risk of COVID-19 infection is associated with increased personal space (Holt et al., 2022). Since personal belongings also can be the source of infection through aerosols, the perceived risk of infection may extend to them. It is precisely due to the increased subjective perception of risk that, in the context of COVID-19, the extension of personal belongings comes to represent the characteristics of personal space, and the distance between personal belongings also increases. Participants without sufficient prior information could place their belongings at a distance from the confederate’s belongings to avoid contamination as they were unsure whether the stranger and their belongings were infected with viruses. Moreover, some previous studies declared that the confined spaces may enhance the feeling of personal space invasion, thereby increasing psychological stress and anxiety (Aiello et al., 1977; Evans, & Wener, 2007). In the present study, for strict replication and fair comparison, the chair distance was set to be the same as in the original experiment conducted in the pre-pandemic period, but the small distance between chairs may have created a sense of social anxiety and constriction at the beginning, making participants place belongings farther away to alleviate seated proximity in subsequent place sessions. No studies that have been done to illustrate the effect of physical proximity on the unraveling of the distance between items.

Another possibility is that participants tried to be compliant. In the US, a 1% increase in new cases (deaths) in the last seven days is associated with a 3% (11%) increase in social distancing intensity (Besley and Dray, 2022). In Japan, the number of cases and deaths is reported daily in the news which could maintain a high level of compliance (i.e., willingness to distance themselves socially). In fact, all valid participants in this study voluntarily wore face masks, which is a routine infection control measure. Beyond compliance, mask-wearing might have also influenced the observed spatial distancing behavior. Research has shown that wearing face masks can alter interpersonal perceptions and decrease interpersonal and peripersonal distances in certain contexts. For example, Cartaud et al. (2020) found that individuals perceived as wearing face masks are considered more trustworthy, leading to reduced physical distance. Similarly, Biggio et al. (2022) reported that mask-wearing shapes interpersonal space by fostering a sense of safety and reducing the need for extended spatial boundaries. In our study, while participants wore face masks during the experiment, the observed increase in distance between personal belongings suggests that compliance with infection control measures and risk-avoidance behaviors might interact differently when participants place objects instead of interacting directly with people. We speculated that participants may have maintained a distance between belongings to ensure compliance. This compliance-based explanation can coexist independently with the above explanation of infection avoidance.

Intriguingly, our study did not find a significant effect of the confederate’s friendliness on participants’ behavior, as indicated by the lack of a significant interaction effect in the ANOVA. This result appears to be inconsistent with the findings from Ariga (2016). One possible explanation for this discrepancy could be a ceiling effect, where participants’ behavior might have already reached its peak, limiting the observable impact of additional friendliness. In other words, the width of the desk (150 cm) was long enough in the pre-pandemic period (Ariga, 2016), but may have been too short to study the effect of the confederate during the pandemic period (see Figure 1). Although the confederate experimenters tried to place their belongings as far as possible to the left corner of the desks, the space left to the participants was estimated to be about 110 cm. The size of 110 cm minus each participant’s belongings was the maximum distance that the participant could set. The distribution of the data in terms of the COVID-19 pandemic reached close to this maximum distance. If the desks were much longer, participants would have been able to place their belongings at a distance from the unfriendly person’s belongings without worrying about the risk of their belongings falling off. The replicability of the original phenomenon in the confederate itself needs to be confirmed by more replication studies.

Although there is a large difference between the present study and Ariga (2016) in terms of the COVID-19 pandemic, other potential differences could have existed as hidden moderators, which might have impacted the results. For example, Rissho University, where the Ariga (2016) experiment was conducted, is in Tokyo, while Kyushu University, where we conducted the present study, is in the deep mountainous countryside. Many of the students at Rissho University, the sample from which the pre-pandemic data was generated, use fully crowded trains to commute to campus every day, possibly affecting one’s personal space.

In addition, about a decade has passed since Ariga’s (2016) data collection and the present study. Therefore, we should consider that changes, unrelated to the pandemic, might have occurred in the long term. For example, in the 2010s, smartphones became widespread in Japan, and hence, social media and social networking services (SNS) have greatly developed (Ministry of Internal Affairs and Communications, 2017). Although this is just a speculation, the distance for social interaction may have changed over time, as such communication without the effect of physical distance from the other person becomes mainstream. This issue can be addressed in the future by examining the relationship between personal spaces and SNS use. In addition, it would be important to consider other factors such as mood, interpersonal anxiety, and other person-related characteristics.

To dissociate the factor of the pandemic from other potential factors, conducting the study using the same procedure again after the pandemic would be effective. Additionally, future studies should further examine how interpersonal and peripersonal distances interact in different contexts. For example, the level of perceived infectability (i.e., beliefs about one’s own susceptibility to infectious diseases) in 2023 has dropped to the same level as before the COVID-19 pandemic in Japan (Ikeda et al., 2024). Although the number of diagnosed COVID-19 cases remains high, people’s subjective risk perception has declined. The potential changes in sensitivity suggested by such reports provide us with numerous possibilities for discussion. Would the effect still emerge when the perceived risk of infection is low? Additionally, would it manifest if participants were asked to place items they do not own? Alternatively, the persistence of the effect—despite the lack of influence of the confederate’s friendliness—suggests that the expansion of peripersonal space during the pandemic might be independent of social cues. Furthermore, the perception of distance may be shaped by long-term societal and technological changes. The widespread use of smartphones and social media in the 2010s might have altered norms around physical proximity and social interaction. Future research could investigate whether personal space norms adapt to such technological shifts and how these changes interact with interpersonal and peripersonal distances. If future research compares the data of Ariga (2016), the present research, and future research, such as a single case design (i.e., ABA design), they can extract the impact of the COVID-19 pandemic to our personal space more clearly than our study. Alternatively, examining the association between the impact and individual differences in disgust proneness (Haidt, McCauley, and Rozin, 1994; Curtis, De Barra, and Aunger, 2011) or compliance (Zajenkowski et al., 2020) might be helpful. This pandemic has inspired researchers worldwide, and too many papers were published (Pai, 2020). However, it is essential to reverify scientific knowledge, including our study, in the post-COVID-19 era. This should lead to strong knowledge in preparation for the next pandemic.

Conclusion

In summary, this study examined expanded personal space during the COVID-19 pandemic. Personal space is modulated by several factors including gender, personality traits (Khmiliar et al., 2020), mental status (Park et al., 2009; Schoretsanitis et al., 2016; Kennedy et al., 2009), and social function (e.g., social cognition; Holt et al., 2015). The distance of personal space serves as a mechanism to avoid disease when the body is threatened by a virus (Park, 2015). Thus, specific conditions in which the threat of infection is extremely high, such as the COVID-19 pandemic, could motivate people to place belongings at increasing distances from others. Although the present study could not clarify the mechanism of this phenomenon and has several limitations discussed above, the results show that people significantly increased, with a large effect size, the distance between personal belongings during the COVID-19 pandemic. It is important to note, however, that the results of the present experiment do not fully demonstrate that COVID-19 was the only factor that affected the expanded personal space between belongings. Without regard to personal favorability, the distance between personal belongings now is already twice as great as that in pre-pandemic. Our results provide new insights into future spatial design of public spaces. Not only the social distance between people’s seats but also personal belongings need their ‘own space’ in open places. For example, but not limited to, lockers (or shelving) in gyms and large public baths should be increased in space to ensure the psychological safety and comfort of users.