A growing body of research is shedding light on an unsettling link between a simple beverage choice and darker aspects of human personality — with scientists claiming that people who prefer their coffee black are more likely to exhibit psychopathic tendencies.
The findings come from a series of psychological studies conducted over the past decade, culminating in a comprehensive analysis by a team of behavioral scientists in Austria and the United States. Their work suggests that taste preferences — particularly a fondness for bitter flavors — may correlate with certain antisocial traits, including narcissism, sadism, and even subclinical psychopathy.
Lead researcher Dr. Christina Sagioglou of the University of Innsbruck told Scientific American that the connection appears to be more than coincidence. “We consistently found that individuals who enjoy bitter-tasting foods and drinks, such as black coffee, tonic water, or dark chocolate, scored higher on personality assessments measuring manipulativeness, callousness, and a lack of empathy,” she said.
To arrive at this conclusion, researchers surveyed more than 1,000 adults about their taste preferences and then had them complete standardized personality questionnaires, including the “Dark Triad” test, which measures psychopathy, narcissism, and Machiavellianism. The results, published in the journal Appetite, found a statistically significant relationship between bitter flavor enjoyment and higher dark personality trait scores.
A new study suggests that your morning coffee order might reveal more about your personality than you think — and if you drink it black, you could be scoring higher on psychopathy scales. pic.twitter.com/qMnZBVoYlw— Science Today (@ScienceToday) August 13, 2025
While the idea has sparked fascination — and plenty of jokes online — psychologists stress that enjoying black coffee does not automatically make someone a psychopath. “Correlation is not causation,” said Dr. Sagioglou. “The vast majority of black coffee drinkers are perfectly normal, kind people. But statistically speaking, the preference is more common among those with these traits.”
Part of the explanation may lie in how people experience bitterness. Evolutionarily, bitter tastes signaled danger — many toxic plants and substances are bitter — so most humans are wired to avoid them. Those who enjoy bitterness, experts say, may have a higher tolerance for discomfort or even seek it out, traits sometimes linked to thrill-seeking or antagonistic behavior.
Dr. Jennifer MacDonald, a forensic psychologist in Los Angeles, told Psychology Today that the research aligns with her clinical observations. “In forensic settings, we often see a disregard for social norms and an attraction to sensory extremes. A fondness for bitter, unadulterated coffee could be part of that broader pattern.”
Interestingly, the study also found that people who preferred sweeter coffee tended to score higher on measures of agreeableness and empathy. “It doesn’t mean putting sugar in your latte makes you an angel,” Dr. MacDonald said with a laugh. “But it does suggest personality traits influence even our most mundane daily choices.”
Social media has embraced the findings with a mix of amusement and alarm. One viral tweet read: “My boyfriend drinks black coffee and sleeps with the window open in winter. Suddenly I’m rethinking my life choices.” Another user joked, “Psychopath? No. Just lactose intolerant.”
If you drink black coffee, science says you might be a psychopath. But if you put oat milk in it, you’re just in denial. pic.twitter.com/dvBqPQoEF7— Pop Culture & Science (@PopSciBuzz) August 13, 2025
Still, the implications of the research are being taken seriously in some circles. Behavioral analysts say such correlations could one day be used in profiling or even in targeted advertising. “Your online coffee order history may reveal more than you realize,” said Dr. Alan Roberts, a data scientist who works with consumer behavior models. “If marketers — or law enforcement — wanted to build psychological profiles, taste preferences could be one more data point.”
However, not all experts are convinced. Critics argue that personality is far too complex to be distilled down to a single dietary habit. “It’s entertaining science, but we need to be careful,” said Dr. Paul Bloom, a Yale psychologist. “There’s a risk of oversimplification and stigmatizing harmless preferences.”
Further research is underway to understand whether the link is culturally universal or influenced by regional habits. In countries where black coffee is the norm, such as Turkey or Ethiopia, the correlation may be weaker or absent. “Context matters,” Dr. Sagioglou emphasized. “In some cultures, black coffee is simply the default, so personality differences may not show up the same way.”
For now, the takeaway is that your morning brew might say something about you — but it’s far from a definitive personality test. As Dr. MacDonald put it: “Enjoy your coffee however you like. Just don’t use it as an excuse for bad behavior.”
In the meantime, the internet continues to run wild with the idea. Coffee shops have even started making tongue-in-cheek posts warning customers: “Black coffee drinkers — we’re watching you.” Whether it’s science, superstition, or just a conversation starter, it seems this study has cemented black coffee’s place not just in our mugs, but in the psychology of everyday life.