If your one of the slim few who likes their coffee boring and plain, I'm talking black then you might a psychopath.
The University of Innsbruck in Austria discovered that people who enjoy their food or drinks on the bitter side are linked to possessing psychopathic traits and sadism.
Intriguing.
Over 900 people were surveyed during the study being asked questions relating to narcissism, psychopathy, and the "Big Five" personality traits. The survey revealed that people who like bitter food and drinks had more daily engagement with sadism.
If you're unfamiliar that's when you get pleasure from pain. Like, "Fifty Shades of Grey" stuff.
So the real question is how do you like your coffee?