Studies published in a wide range of academic journals show that face masks negatively impact social bonds and communication by obscuring facial expressions and by degrading the volume and quality of speech. A study published in May 2021 by the journal Frontiers in Psychology found that these problems are "are significantly pronounced in children aged between 3 and 5 years old" and that "sensitivity to facial emotion movements is fundamental to children's emotional processing and social competence." While ignoring this evidence, the American Academy of Pediatrics claimed in August 2021 "there is no evidence that use of face masks prevents or delays speech and language development." One month later, the UK Department of Education published a survey that found 96% of teachers "thought that wearing face coverings has made communication between teachers and students more difficult, with 59% saying it has made it a lot more difficult."