Are you wondering whether to trust someone you recently met? Here's a simple test: Casually ask your potential mate, friend, or employee what kinds of foods they particularly relish. If they tell you they enjoy bitter-tasting fare, run far, far away.
In a newly published study, University of Innsbruck psychologists Christina Sagioglou and Tobias Greitemeyer find that a preference for bitter tastes is associated with a variety of malevolent personality traits. In the journal Appetite, they report finding a particularly robust relationship between enjoyment of such dishes and "everyday sadism."
The words "kale" and "kill" do sound awfully alike, don't they?
This research is the latest in a series of surprising studies suggesting a relationship between food preference and personality. A 2011 study found people with a sweet tooth are more likely to have—you guessed it—a sweet personality, while another study published last year found eating or drinking bitter food can lead people to act in aggressive, hostile ways.
People who regularly act in cruel ways insist that they enjoy bitter foods.
Those results led Sagioglou and Greitemeyer to wonder if a preference for bitter tastes was related to dark personality traits. "There is growing evidence that food preferences are genetically influenced," they write.
To find out, Sagioglou and Greitemeyer conducted two studies, the first of which featured 504 people recruited online. Participants began by indicating the extent to which they enjoyed sweet, sour, salty, and bitter foods in general, as well as specific examples of each category (chocolate cake for "sweet," coffee and radishes for "bitter.")
They then responded to a series of statements designed to measure a variety of personality characteristics—basic ones like extroversion, openness, and conscientiousness, but also dark traits such as aggressiveness, narcissism, and sadism.
The latter quality was measured by their response to such statements as "When making fun of someone, it is especially amusing if they realize what I'm doing," which Sagioglou and Greitemeyer scored using a five-point scale ("strongly disagree" to "strongly agree").
The results "showed the expected correlations between general bitter taste preferences and a number of noxious personality and behavioral tendencies," the researchers write. The most robust associations they found were for everyday sadism (the tendency to engage in unprovoked cruelty) and psychopathy (a mental disorder marked by amoral, anti-social behavior and a lack of remorse).
Their second study, which featured 449 people recruited online, produced similar results. Analyzing both, the researchers conclude that "everyday sadism (and, with a strong tendency, psychopathy) was consistently and robustly associated with general bitter taste preferences."
Sagioglou and Greitemeyer add an important caveat: These results did not hold up when people were asked whether they liked certain specific bitter foods, including radishes and black coffee (rather than bitter foods as a category). That suggests sadists' fondness for bitter tastes may be more theoretical than real, or that they have a different standard for bitterness than the rest of us.
While more research is needed before we can draw definitive conclusions, it is telling that people who regularly act in cruel ways insist that they enjoy bitter foods. This may be a way of telling us they walk around with a bitter taste in their mouths—and, disturbingly, that they have come to enjoy it.
Findings is a daily column by Pacific Standard staff writer Tom Jacobs, who scours the psychological-research journals to discover new insights into human behavior, ranging from the origins of our political beliefs to the cultivation of creativity.