In the news: If you can thrive after only four hours of slumber, you may be a short sleeper. According to the Business Insider, short sleepers are those who tend to be more optimistic, physically active and seem to otherwise thrive despite having less than average amounts of sleep (typically 7-8 hours).
Scientists have been able to identify genes common in short sleepers. Some of those genes appear to have a hereditary link. Short sleeping, while appearing harmless for some, is still considered a sleep disorder.