A novel coronavirus, SARS-CoV-2, has now spread widely throughout the world. Due to the virus’ high transmission rate, relatively long incubation period, and increased mortality rate in people with certain conditions (e.g., older people), the World Health Organization (WHO) has provided guidelines to help prevent the public from becoming infected with the virus (1). The clinical course of the coronavirus disease, COVID-19, appears to be relatively mild in children compared to other populations (2, 3), although infants were found to be at high risk of becoming severely or critically ill (4). Nevertheless, the effects of the societal changes implemented to decrease the likelihood of SARS-CoV-2 infection on children’s cognitive, social, and emotional development are unknown. According to Bronfenbrenner (5), child development is a function of the interaction between several systems and includes culture, parental occupations, schooling, peer relationships, and parenting. Thus, changes in one system can directly or indirectly affect children’s development. In the case of COVID-19, the pandemic can affect parents’ work, children’s schooling, and media use by both children and adults, which may in turn have significant effects on children’s cognitive, social, and emotional development.
Common strategies to prevent infectious diseases include requesting people to stay at home, avoiding crowds or large gatherings, and practicing social distancing. Indeed, people in several countries have been prevented from going to work or school including kindergarten, and have fewer opportunities for in-person communication during the COVID-19 pandemic. The public health policy, referred to as quarantine, is characteristic of infectious diseases including the COVID-19 pandemic, compared to other negative events, such as natural disasters or terrorism. Although quarantine may play a major role in preventing the spread of COVID-19 cases (6), it may cause psychological problems such as depression, irritability, and anxiety (7, 8). Given that children may be more vulnerable to such situations than adults, we need to identify children’s problems and, if necessary, support them accordingly. Several psychological studies have already examined the effect of the COVID-19 pandemic on children’s mental health (e.g., depression, anxiety) (9–12). However, due to the nature of quarantine (the lack of social relationship with peers and teachers), children may have problems in socio-emotional behaviors (e.g., hyperactivity, prosocial behavior). It remains unclear whether the COVID-19 pandemic affects children’s socio-emotional behaviors. One study in Italy and Spain reported that children experienced emotional and behavioral problems (e.g., difficulty concentrating) after the pandemic outbreak (11), but this study did not assess the population before the pandemic and thus the change in emotional problems could not be compared. Therefore, the present study examined differences in children’s socio-emotional behaviors before and during the pandemic.
Moreover, even though children have problems in socio-emotional behaviors, supporting children in-person may be difficult because of the widespread disease. In that case, children can benefit from digital technology, such as online communication and learning. Indeed, it has been proposed that technology may be essential during a time of isolation and social distancing and can support the wellbeing of children (13). Although the online support is still limited presently, we believe that it may be potentially useful for children because even young children are capable of using digital technology. Furthermore, previous studies have shown that children can operate digital devices at the beginning of early childhood (14, 15). Children have the specific touch skills required to operate digital devices, such as the pinch, and tap gestures, and know how to utilize many of the functions of digital devices, such as video-calling (16).
Moreover, children may accelerate the development of digital skills under the COVID-19 pandemic; hence, it can be more beneficial to receive online support or online learning when they have problems in socio-emotional behaviors. Many children cannot go to school due to the pandemic, and therefore may have increased opportunities to use digital devices, for instance, to receive online education. For example, the Chinese government started a large-scale, normal online education campaign during the pandemic (17). Consequently, children’s skills in using digital devices may improve as they gain more experience. Therefore, in this pre-registered study, in addition to examining differences in children’s socio-emotional behaviors, we assessed whether children showed differences in operating digital devices before and during the pandemic.
In Japan, the first person infected with SARS-CoV-2 was identified in January 2020, and the number of infected people has since increased although the growth rate was lower than in many other countries [18]. On 27 February 2020, the government asked all schools across the country to close until March 2020, and the vast majority of schools complied (but nursery schools did not). Schools started to re-open at the beginning of April 2020, but the government declared a state of emergency covering seven prefectures including Tokyo and Osaka on 7 April 2020. Thus, most schools in seven prefectures closed whereas about 80% of the kindergartens and half of the elementary schools in the other prefectures started to open on 10 April 2020 (19). Subsequently, the declaration to close schools was extended to all regions on 16 April 2020, and most schools in all prefectures closed until 6 May 2020. Thus, data for the during-pandemic sample was collected when most of the schools were closed and children had less time for schooling and meeting with friends.