> this paper does not estimate the effect of wearing masks, but rather the effect of mandating mask wearing
This study doesn't control its variables properly. Places with no mask mandates are also places where people typicaly didn't take other precautions such as avoiding mass gatherings.
Anecdotally, when my son was in online classes and later on in person but masked he made remarks to me about how he felt like he had no friends and people didn't like him.
Partially(mostly?) was because during class breaks they were not allowed to interact.
"The hypotheses for the influence of face mask wearing on emotion recognition were partially supported. Results showed that whereas anger was better recognized, happiness and sadness were impaired in their recognition.
...
Therefore, the differential impact of face masks on emotion recognition can have an effect on children’s social interactions. For example, better recognition of anger can facilitate greater physical and social distance from one another (Calbi et al., 2021). On the other hand, lower recognition of happiness and sadness can be potentially detrimental for children’s social interactions. Happiness has been identified as key to boosting social interactions (Quoidbach et al., 2019), whereas recognizing sadness in others is important to display appropriate interpersonal emotion regulation (Kwon & López-Pérez, 2022)."
This study doesn't control its variables properly. Places with no mask mandates are also places where people typicaly didn't take other precautions such as avoiding mass gatherings.