Enjoy black coffee? You may be a psychopath

London: A fondness for bitter-tasting food and drinks, such as black coffee, may be a sign of dark personality traits, including Machiavellianism, sadism and narcissism, according to a new study.

Christina Sagioglou, study author and psychologist at the University of Innsbruck in Austria, and her colleague Tobias Greitemeyer, studied how bitter taste preferences may be associated with antisocial personality traits.

About 1,000 particpants with an average age of 35 were analysed in two experiments.

In the first experiment, 500 men and women were shown a long list of foods with equal numbers of sweet, salty, sour, and bitter and were asked to rate them on a six-point scale ranging from "dislike strongly" to "like strongly."

The participants then completed four separate personality questionnaires that measured their levels of aggression by asking them to rate statements that resonated with them, such as "Given enough provocation, I may hit someone."

For the second half of the experiment, participants were asked to rate how strongly they agreed or disagreed with statements that assessed personality traits of psychopathy, narcissism and Machiavellianism - which is characterised by a cynical disregard for morality and a focus on self-interest and personal gain.

The participants were also asked to answer questions relating to the "big five" personality traits - extraversion, agreeableness, conscientiousness, and emotionality stability, 'Medical Daily' reported.

Everyday sadism was assessed by the Comprehensive Assessment of Sadistic Tendencies.

The second experiment assessed their preferences for food tastes, except the list was reduced to 20 items ? sweet and bitter. The participants also had the choice to choose "I don't have an option" to each of the food items.

Based on both experiments, the researchers concluded bitter taste preferences were linked to malevolent personality traits.

"General bitter taste preferences emerged as a robust predictor for Machiavellianism, psychopathy, narcissism, and everyday sadism," the researchers said.

For people with sadistic traits, the consumption of bitter foods was comparable to a rollercoaster ride, where they enjoyed things that induced fear, according to Sagioglou.

The study was published in the journal Appetite.