Interesting study, but there are some potential issues. One is that it is small, about 100 students. The other is that the demographics of the students at the

Interesting study, but there are some potential issues. One is that it is small, about 100 students. The other is that the demographics of the students at the second school shift between the 2 years. This may confound the study due to cultural differences. For example, in my limited experience, it seems that white parents are more strict about bedtime than Asian parents, and if that is the case, more sleep may simply be a result that the second group had parents who pushed stricter bedtimes. From: https://advances.sciencemag.org/content/advances/suppl/2018/12/10/4.12.eaau6200.DC1/aau6200_SM.pdf https://advances.sciencemag.org/content/advances/suppl/2018/... School RHS FHS Year 2016 2017 2016 2017 Students 51 41 41 41 % Female 53 49* 56 58 % White 76 75 2 19 % Asian 10 5 54 46 % Hispanic 6 5 7 7 % African American 8 5 32 22 % Unknown/other 0 10 10 10 Age (mean ±SEM) 16.08 ± 0.05 16.27 ± 0.08 16.13 ± 0.05 16.13 ± 0.06 I would take these results with a grain of salt.