Psychologists have found that those with a preference for bitter tastes were more likely to exhibit signs of Machiavellianism, sadism, and narcissism.
That is, they were more prone to being duplicitous and self-serving, cold-hearted and lacking in empathy, vain and selfish, and more likely to derive pleasure from other people's pain.
The findings of the study provide the 'first empirical evidence that bitter taste preferences are linked to malevolent personality traits,' said the researchers from Innsbruck University in Austria, who studied 1,000 people in two separate experiments.
'The results suggest that how much people like bitter-tasting foods and drinks is stably tied to how dark their personality is.'
Bitter foods include unsweetened cocoa, black coffee, radishes and the quinine in tonic water.
For the first experiment, 500 men and women were shown a long list of foods with equal numbers of sweet, salty, sour and bitter foods. These included chocolate cake, bacon, vinegar and radishes.
They were asked to rate how much they liked each of them on a six-point scale ranging from dislike strongly to like strongly.
The participants, who had an average age of 35, then completed four separate personality questionnaires.
The first measured their levels of aggression by asking them to rate how much statements such as 'Given enough provocation, I may hit someone' sounded like them.
For the second, participants were asked to rate how strongly they agreed or disagreed with statements designed to assess the personality traits of Machiavellianism, psychopathy and narcissism.
Example questions in each of these sections included 'I tend to manipulate others to get my way', 'I tend to be callous or insensitive' and 'I tend to want others to pay attention to me', respectively.
Next, the participants answered questions relating to the 'Big 5' personality dimensions of extraversion, agreeableness, conscientiousness and emotional stability.
And lastly they completed the Comprehensive Assessment of Sadistic Tendencies, which assesses a person's tendency towards 'everyday sadism'.
This involved rating on a scale how much they agreed or disagreed with statements such as 'When making fun of someone, it is especially amusing if they realise what I'm doing', and 'I enjoy tormenting people'.
'General bitter taste preferences emerged as a robust predictor for Machiavellianism, psychopathy, narcissism and everyday sadism,' the researchers wrote in the journal Appetite.
Agreeableness – the extent to which a person is kind, sympathetic and cooperative– was negatively correlated with bitter taste preferences, they added.