The consequences of COVID-19 on social interactions: an online study on face covering

The COVID-19 pandemic has dramatically changed the nature of our social interactions. In order to understand how protective equipment and distancing measures influence the ability to comprehend others’ emotions and, thus, to effectively interact with others, we carried out an online study across the Italian population during the first pandemic peak. Participants were shown static facial expressions (Angry, Happy and Neutral) covered by a sanitary mask or by a scarf. They were asked to evaluate the expressed emotions as well as to assess the degree to which one would adopt physical and social distancing measures for each stimulus. Results demonstrate that, despite the covering of the lower-face, participants correctly recognized the facial expressions of emotions with a polarizing effect on emotional valence ratings found in females. Noticeably, while females’ ratings for physical and social distancing were driven by the emotional content of the stimuli, males were influenced by the “covered” condition. The results also show the impact of the pandemic on anxiety and fear experienced by participants. Taken together, our results offer novel insights on the impact of the COVID-19 pandemic on social interactions, providing a deeper understanding of the way people react to different kinds of protective face covering.

www.nature.com/scientificreports/ in the United States in the spring of 2020, showed that women are more prone to wear a sanitary mask than men, and that men feel more negative emotions when wearing a face covering 16 . Few other studies mainly focused on the social negative consequences of wearing a sanitary face mask [20][21][22][23] . Indeed, the presence of the sanitary mask may influence not only the recognition and comprehension of others' emotions, but given its current status as a contextual cue of the pandemic, also the attribution of physical and social distance. The physical distance that people maintain between themselves and others, typically defined as "interpersonal space" 24,25 , can expand or shrink depending on the situational context 24,[26][27][28] . Indeed, it is well known that intrusions into this "personal space" induce a sense of threat and discomfort in individuals 24 . For instance, previous studies have demonstrated that individuals affected by traumatic events keep larger interpersonal distance, such as physically abused children 29 and adults with post-traumatic stress disorder 30 .
On the other hand, it has been theorized and demonstrated that, after a traumatic collective event such as a pandemic, social distancing from members of one's community is modulated in the opposite direction (i.e., people reduce social distancing), resulting in a renewal of the community's sense of social bonding 31 . In other words, the common effort to fight the pandemic could augment cooperation and shared values among individuals, thus leading to the perception of being a more united and tight community with the same destiny 15 .
Another aspect to be considered is the role of virus-linked fear and stress, as they can compromise psychological resources (e.g., empathy) useful to deal with social interactions 15 .
In light of the aforementioned studies, the purpose of the present study is to understand the consequences of the COVID-19 pandemic on our ability to effectively interact with others. Specifically, the aim of the present study is fourfold: (1) to investigate how the perception of emotional facial expressions is influenced by the covering of lower-face features by different kinds of protective face-covering within the context of the COVID-19 first pandemic peak; (2) to investigate whether protective face-covering influences the attribution of physical distance as well as the perceived social distance from others; (3) to explore gender differences; (4) to investigate the current fear of COVID-19 in more detail and its relation with other personality factors.
To this aim, by means of a study available online between May 12th and June 1st 2020, Italian participants were shown static facial expressions (Angry, Happy and Neutral) in two different conditions of "covering": by a sanitary mask and by a scarf. The scarf was chosen for its ecological validity, guaranteeing at the same time that the same portion of the face (from nose to neck) was covered. It has to be stressed that, while the sanitary mask is a personal protective equipment which ensures high protection, the scarf is not as effective as the sanitary mask, ensuring low protection from infection 32 . Participants were asked to evaluate: the emotion expressed (in terms of valence and explicit categorization), the physical distance and social distance one would adopt with the person depicted in each stimulus. With regard to emotional evaluations, we expected an impairment in the recognition of happy facial expressions as the recognition of this emotion is most affected by the covering of the lower face. We also hypothesized an increase in physical and social distance attribution to negative facial expressions. For all these aspects, a significant difference between stimuli covered with a sanitary mask and those covered with a scarf could be expected depending on the intrinsic negative value ascribed by participants to the two kinds of protective equipment, both contextual cues of the current pandemic.

Materials and methods
Participants. Ninety-six healthy Italian volunteers took part in the study: 47 females and 49 males, mean age 36.2 years old (Standard Deviation-SD = 16; min = 19, max = 82). Participants were recruited by posting announcements on social networks. The sample is quite heterogeneous, although not fully representative of the entire Italian population, with an over-representation of the age group 25-55 years old (N = 55; 57.29%) at the cost of age group > 55 years old (N = 18; 18.75%) and < 25 years old (N = 23; 23.96%). Furthermore, participants spent the COVID-19 pandemic lockdown in different regions of Italy, with an over-representation of Lombardy (30.2%), Emilia-Romagna (27.1%) and Sicily (15.6%), at the cost of other regions. For more details about the sample, please see Supplementary Materials and Supplementary Table S1 online.
The study was conducted in accordance with the Declaration of Helsinki (2013), according to the ethical standards of the Italian Board of Psychologists, as well as the Ethical Code for Psychological Research of Italian Psychological Society. As the study did not involve clinical treatments or the use of biomedical equipment with clinical implications and taking into account the necessity to run the online study promptly, approval from the local ethical committee was ruled as unnecessary. All participants provided informed consent to participate by selecting "I confirm that I have understood the terms of the present study", thus declaring: "(i) to voluntarily adhere to the implementation of the research as a participant; (ii) to be aware that the recorded data will be analyzed exclusively for research purposes in absolute anonymity; (iii) to be aware that it is not possible to receive the recorded data back once sent".
Power was calculated a-posteriori by means of GLIMMPSE 33 (https ://v3.glimm pse.sampl esize shop.org/#) using the Hotelling-Lawley Trace to test for a repeated-measures design with two within-factors and the Condition by Emotion interaction. The significance level was set α = 0.05 resulting in an actual power > 0.80 with our sample size.
Procedure. We created a study to be administered online by means of Psytoolkit 34,35 . It was composed of (1) a "socio-demographic section" divided into eight different randomized parts, each dedicated to the collection of various information (for a description see Supplementary Materials and Supplementary Tables S1-S2 online), and of (2) an experimental section dedicated to the investigation of the influence exerted by the personal protective equipment (mask and scarf) on facial expressions comprehension and on attribution of both physical and social distance. Stimuli were composed by Angry, Happy and Neutral facial expressions (6 females, 6 males) selected from the Karolinska Directed Emotional Faces-KDEF 36  www.nature.com/scientificreports/ software (cc2019); specifically, a sanitary mask (from now on "High protective equipment", HP) or scarf (from now on "Low protective equipment", LP) was added to the faces, making sure that the same portion of the face (from nose to neck) was covered in the two conditions (see Fig. 1). Each stimulus was randomly presented four times, one for each of the following four questions: (a) Valence: "How would you judge the valence of the expressed emotion?". Participants were asked to answer the questions using a Visual Analog Scale (VAS) from − 50 (negative) to 50 (positive); (b) Explicit categorization: "Which label would you choose to describe the person's emotion?". Participants were asked to choose the most appropriate emotional label in a group of seven (Anger, Happiness, Disgust, Fear, Neutral, Sadness, Surprise); (c) Social distance: The Inclusion of Other in the Self-IOS 37 scale was used by asking: "Which picture best describes your relationship with this person (as if s/ he was a member of your community)?". Participants were asked to answer selecting one of the seven images (i.e., pair of circles) in the IOS; d) Physical distance: "How (physically) distant would you like to keep this person away from you?". Participants were asked to answer by means of a VAS ranging from 0 (very close distance) to 100 (very high distance). Hence, this experimental section was composed of 288 "trials" in total, with the following design: 3 Emotions (Anger, Happiness, Neutral) * 12 Actors (Female, Male) * 2 Conditions (HP, LP) * 4 Questions (Valence, Explicit Categorization, Physical Distance, Social Distance). All questions were delivered in Italian. Participants were asked to observe each stimulus and to answer the question positioned below without any time constrains. Two different versions of the study were created balancing the presentation order of the two sections (socio-demographic section followed by experimental section vs. experimental section followed by socio-demographic section).      Post-hoc tests showed that it was more likely that participants rated Angry facial expressions with lower ratings (i.e., more social distance) than both Happy (z = − 44.37, SE = 0.06, p < 0.001) and Neutral ones (z = − 25.24, SE = 0.05, p < 0.001). Furthermore, it was more likely that participants rated Happy facial expressions with higher ratings (i.e., less social distance) than Neutral facial expressions (z = 23.4, SE = 0.05, p < 0.001). The model also revealed a significant main effect of Participants Gender (χ 2 (1) = 316.4, p < 0.001), showing that Female participants were more likely to give lower ratings than Male participants (z = − 8, SE = 0.04). Furthermore, the main effect of Stimuli Gender was significant (χ 2 (1) = 1323.36, p < 0.001): it was more likely that participants rated Male stimuli with lower ratings than Female stimuli (z = 4.9, SE = 0.04). A significant Condition*Gender of Participants' interaction was also found (χ 2 (1) = 48.8, p < 0.001). Post-hoc test showed that Male participants were more likely to choose higher ratings for facial expressions covered with HP than for those covered with a LP (z = 4.7, SE = 0.06, p < 0.001), while Female participants did not distinguish between the two conditions (z = 1.1, SE = 0.06, p > 0.05). Furthermore, Female participants were more likely to choose lower ratings than Male participants (Mask: z = − 7.39, SE = 0.06; Scarf: z = − 3.93, SE = 0.06, Ps < 0.001) (See Fig. 4b). The model also showed a significant Emotion* Gender of Participants' interaction (χ 2 (2) = 112.02, p < 0.001). Post-hoc tests revealed that Female participants were more likely to choose lower ratings than Male participants for both Angry and Neutral facial expressions (Anger: z = − 9.5, SE = 0.08; Neutral: z = − 4.4, SE = 0.07, Ps < 0.001).

Discussion
The results of the present behavioral experiment show that for Valence ratings both Female and Male participants rated Angry facial expressions as more negative than both Happy and Neutral ones, and they rated Happy facial expressions more positively than Neutral ones. Nonetheless, Female participants gave more negative ratings than Male ones when evaluating Angry and Neutral facial expressions, and more positive ratings when evaluating Happy facial expressions (see Fig. 2). While these results show that participants rated the Valence in accord with the expressed emotion, they also reveal a polarizing effect of ratings in Females. This is consistent with previous studies demonstrating women' stronger sensibility to face stimuli (e.g., higher ratings for experienced valence and arousal, greater attention to the eyes, better decoding of emotions through facial expressions, and greater electro-cortical responsivity) [52][53][54][55][56] . Remarkably, the absence of a significant interaction between Emotion and Condition suggests that the presence of a HP or a LP does not modulate emotional evaluations of this kind. One www.nature.com/scientificreports/ could have expected lower positive ratings for Happy facial expressions covered with a scarf, which, by guaranteeing less protection for the interacting individuals, assumes a more negative contextual value. Indeed, previous studies demonstrated that contextual cues (e.g., Islamic vs. Western headdress) can bias perception toward more intense negative emotions, making the recognition of happiness more difficult 9,10 . We could hypothesize that, apart from methodological differences with previous studies, Islamic headdresses, representing cultural and religious symbols capable to evoke in-group/out-group dynamics and stereotypes 10 , are more rooted contextual cues than HP/LP, thus biasing and affecting the perception of emotions. Results for the explicit Categorization of expressed emotions confirm participants' ability to correctly recognize emotional expressions, as they chose emotional labels congruent with the displayed emotions. Interestingly, for Neutral facial expressions, participants also chose the Sadness label more frequently than chance, particularly in the case of Female participants (see Supplementary Table S4 online). Altogether, both the results for Valence and Categorization show that, despite the covering of the lower-face, participants were able to properly recognize the facial expressions of emotions.
Furthermore, results are also characteristic of the empirical challenges posed by operationalizing neutral emotion, and in particular of the recurrence of "negative bias" (i.e., the attribution of negative ratings to neutral stimuli) 57 . It is also possible that participants' psychological state due to the pandemic might have influenced their responses to neutral stimuli.
With regard to Physical Distance, the expressed emotion and the condition of "covering" both influenced the results. Indeed, participants chose to keep the least distance from positive facial expressions, followed by Neutral and Angry ones. Interestingly, Female participants chose to keep greater Physical Distance from Angry facial expressions and less Physical Distance from Happy facial expressions with respect to Male participants (see Fig. 3). These results are coherent with previous studies that demonstrate an increase in interpersonal distance when participants are exposed to Angry rather than Happy facial expressions 58,59 .
With regard to the "covered" condition, less Physical Distance, only in Male participants, was attributed to facial expressions covered by HP than to those covered by LP. This latter result can be explained by the fact that the Scarf offers far less protection from the infection with respect to a sanitary mask, facilitating a higher risk for individuals if distancing measures are not undertaken 32 . Hence, it is shown for the first time that, in a pandemic context, the use of an appropriate protective device reduces the desire to maintain Physical Distance and thus potentially improves interpersonal social relations. Additionally, in accord with previous studies, we found that less Physical Distance was attributed to Female than to Male stimuli 26,60,61 . www.nature.com/scientificreports/ Results for Social Distance revealed that, similarly to Physical Distance, participants chose to keep the least distance from Happy facial expressions, followed by Neutral and Angry ones, and to Female stimuli than to Male ones. While Female participants felt more socially distant than Male for stimuli covered by both HP and LP, only Male participants chose more Social Distance from faces covered with LP. Lastly, Female participants chose more Social Distance from Angry and Neutral facial expressions than Male participants. The results of the Physical and Social Distance are substantially overlapping (see Fig. 4): Females show a greater tendency, compared to Males, to keep at distance the negative or ambiguous faces regardless of the type of protective equipment (HP or LP). This is very interesting, because the need to maintain greater distance from potentially dangerous stimuli in Females seems to be driven by the emotional content of the stimuli. Differently, Males' ratings of Social and Physical distances depend on the type of protective equipment. Females, in order to establish social and physical distance from other individuals, use more ' empathic qualities' of faces than Males, whose responses seem to be more dependent on contextual cues.
One could also have expected a difference between Physical and Social distance ratings (i.e., increase of interpersonal/physical distance and a reduction of social distance after a traumatic event; see [29][30][31] ), but it has to be considered the period during which our data was collected. Circulation of the study began on May 12th, 2020, two months after lockdown was initiated in Italy and the World Health Organization announced that COVID-19 would be classified as a global pandemic. Indeed, previous studies demonstrate that the practice of social sharing, which enhances social bonding among members of the same community, initiates immediately after a traumatic event and does not last for longer than three weeks 31,62 .
Given the urgent need to mitigate the psychological consequences of the pandemic 15 , we carried out an investigation of current attitudes toward COVID-19 by correlating the Fear of COVID-19 scale with the Health Anxiety total scores and IRI-Personal Distress subscale scores. Results showed that the higher the scores for Health Anxiety and IRI-Personal Distress, the greater the fear of COVID-19, thus pointing for the first time to a correlation between these personality aspects and suggesting that the fear of the virus can be linked to uneasiness and nervousness during social interactions (see Fig. 5).

Limitations, implications and recommendations.
This study has some potential limitations. Firstly, we should consider that future studies are needed to investigate whether the adoption of additional control conditions would have an impact on results. Secondly, the present study was conducted on a heterogeneous, although not fully representative (for age and regions where participants spent the lockdown period), sample of Italian people. Thirdly, as the sample was composed by Italian people only, we cannot exclude that cultural diversity in the habit of wearing sanitary masks may influence results. Finally, the long duration of the study may have affected participants' attention throughout the experiment.
Taken together, the present results offer novel insights on the consequences of the COVID-19 pandemic on our ability to effectively interact with each other. This study also highlights the impact of the pandemic on anxiety and fear experienced by participants. Future studies are needed to investigate the social and emotional costs of wearing sanitary masks (e.g., for teacher-student and clinician-patient communication as well as for individuals that are hearing-impaired) 22

Data availability
The datasets generated during and/or analysed during the current study are available in the Zenodo repository, http://doi.org/10.5281/zenod o.42699 05.