And don't forget that physical loneliness, that is, actually being alone, eliminates one major feedback source that something could be wrong with your health, or a source of immediate aid if e.g. you go into cardiac arrest.
Maybe the researcher above touches on these things, but more generally, there should be a standardized probability and statistics exam for ALL aspiring scientific researchers, and a high score should be the minimum cutoff. The influence that a statistically flawed study can have over our collective futures is too dangerous.