https://en.wikipedia.org/wiki/Smile_mask_syndrome https://en.wikipedia.org/wiki/Smile_mask_syndrome "Smile mask syndrome ... is a psychological disorder ... i

https://en.wikipedia.org/wiki/Smile_mask_syndrome https://en.wikipedia.org/wiki/Smile_mask_syndrome "Smile mask syndrome ... is a psychological disorder ... in which subjects develop depression and physical illness as a result of prolonged, unnatural smiling. [Professor] Natsume proposed the disorder after counselling students from the university in his practice and noticing that a number of students had spent so much time faking their smiles that they were unaware that they were smiling even while relating stressful or upsetting experiences to him. Natsume attributes this to the great importance placed on smiling in the Japanese service industry, particularly for young women." Somebody better give this researcher a call because he's about to get a whole lot more opportunities to gather clinical data.