Yes, genetic factors are possible. For example, last year a new gene interaction was discovered for people who need less sleep: https://www.nih.gov/news-events/

Yes, genetic factors are possible. For example, last year a new gene interaction was discovered for people who need less sleep: https://www.nih.gov/news-events/nih-research-matters/gene-identified-people-who-need-little-sleep https://www.nih.gov/news-events/nih-research-matters/gene-id...