A little learning is a dangerous thing.
Drink deep, or taste not the Pierian Spring
There shallow draughts intoxicate the brain,
And drinking largely sobers us again.
-- Alexander Pope
A few years ago, two Viennese researchers, Christina Sagioglou and Tobias Greitemeyer, reported in the journal Appetite that people who have bitter taste, and the Big Five factors of personality.
The results of both studies confirmed a hypothesis that bitter taste preferences are positively associated with malevolent personality traits, with the strongest relation to everyday sadism and psychopathy. Regression analyses confirmed that this association holds when controlling for sweet, sour, and salty taste preferences and that bitter taste preferences are the overall strongest predictor compared to the other taste preferences.
So what? The most commonly-reported relationship in on-line sources is that people who like to drink black coffee have higher dispositions toward the dark triad of personality (sadism, narcissism, and psychopathy.
Well, there's a few loose ends.
First of all: there's the cause-and-effect relationship. Does psychopathy and Machiavellianism cause a preference for bitter tasting substances, or what? Not everything is linked in a causal relationship.
Secondly, there's the singling out of coffee. The research was concerned with taste and personality traits, of which bitter is one of the four basic tastes.
To make things interesting, the articles selected black coffee as an example of something bitter-tasting. But it doesn't have to be.
While some coffee can have a bitter taste, bitter-tasting coffee is more likely to occur if the coffee is too finely ground. Use a coarser grind instead.
Second, water at its boiling point (212 F) is more likely to taste bitter. Using water at 195-200 F is best for non-bitter coffee.
Third, coffee tends to be more bitter if the coffee is left to stand. This is why gas station coffee is so bitter.
Fourth, select a better, less bitter type of coffee. Cheap coffees are more likely to be harshly bitter. Shop around.
Fifth, using dirty equipment is more likely to result in bitter coffee. Dirty equipment, with residue of coffees past, is more likely to yield bitter-tasting coffee. Keeping your equipment clean may be the most important step.
In short, you can make a not harshly bitter cup of black coffee if you do it right.
But there's other aspects to coffee. These are the cultural ones.
Some look on it as a quick means of self-medication. These may include the hasty espresso drinkers. And there's the black coffee as an accompaniment to certain jobs. Drinking coffee while performing data entry or being on-line, for example.
Coffee or tea may in some cultures be offered as part of a ritual of hospitality. ("A cuppa," as the English say it.) And some people, dammit, just want it to be bitter!
Disclosure: In general, I prefer a café au lait to black coffee, whether with chicory or not. Anyway, it is possible to enjoy black coffee that is not overly bitter. But use milk; coffee and creamer is a sin; and the good coffee fairy will smite you!