This study relies on finding associations in a large data set, which is not really a complete scientific study. It's at best a hint about where scientists should conduct future research.
If you're just looking at correlations, it can be easy to miss hidden variables, even when attempting to control for them with statistical methods.
Compare with a well-known Standord study where athletes were asked to maximize their sleep, and then their results compared to when they got the "normal" amount of sleep. They showed a notable improvement while maximizing sleep.
If you're just looking at correlations, it can be easy to miss hidden variables, even when attempting to control for them with statistical methods.
Compare with a well-known Standord study where athletes were asked to maximize their sleep, and then their results compared to when they got the "normal" amount of sleep. They showed a notable improvement while maximizing sleep.