That study not only involved a fondness for black coffee, but also noted bitter food like radishes, celery and tonic water. The data showed that "bitter taste preferences are linked to malevolent personality traits ... We found particularly robust correlations with everyday sadism." Whereas people with more "agreeable" personality traits like kindness, tended to dislike bitter tastes.
Coffee itself has healthy benefits like improved brain function. Some may argue that people who drink their coffee black are enjoying the beverage without the added calories. Nevertheless, the Huffington Post says researchers hope that this study will help them look at the connection between eating behavior and personality traits in further studies.