Overview
Almost two-thirds of U.S. adults drink coffee. Visit your local coffee shop and you’ll find what seems to be just as many ways to make it. Frappuccinos, mochas, macchiatos, café lattes, the list goes on. But perhaps the most common way to drink coffee, the preferred choice of about 1 in 3 coffee drinkers, is black. Indeed, there are even numerous ways to make black coffee, such as French press, espresso, pour over, and of course, the classic “drip” brew in a coffee pot.
Coffee culture, much like the beverage, is strong. It made us wonder how people psychologically perceive people who drink certain types of coffee. This wouldn’t be the first time we find such an effect. In one experiment, we found that wine drinkers are perceived to be more sophisticated. Might people who take their coffee black or with milk evoke certain psychological perceptions as well?
A classic pair of outcomes in psychology is warmth and competence. We hypothesized that black coffee drinkers may seem more competent, whereas those who take milk with their coffee might seem more friendly.
Experiment
We recruited 400 people from Amazon Mechanical Turk to view a short vignette about a co-worker drinking coffee, followed by a picture of either black coffee or coffee with milk (randomly assigned).
Participants were told to “Imagine you work in an office and you notice that one of your co-workers is drinking coffee, pictured below.” Participants were then shown one of the two photos below, which were taken by the researcher.
Participants were then asked, “To what extent do you feel each of the following words describe this co-worker? (1 = Not at all, 7 = Very much” using a 1-7 scale. Two words were provided for participants to rate, “Competent” and “Friendly.” Note that we used friendly instead of warm so as not to confuse it with temperature, given that black coffee might be perceived as higher temperature than milk coffee.
Finally, to test whether perceptions differ between those who do and don’t drink coffee, we also measured whether each participant regularly drinks coffee. At the end of the survey, we asked participants “Do you drink coffee at least once every 1-2 weeks?” with answer options “Yes” and “No.”
Results
There was no significant difference in perceived competence between our coffee with milk drinker (avg. = 5.27) and our black coffee drinker (avg. = 5.23), (p = 0.769). Nor was there a significant difference in perceived warmth between milk (avg. = 5.24) and black (avg. = 5.09), (p = 0.253). So neither of our hypotheses were supported.
Lastly, none of the results were affected by whether participants did or did not regularly drink coffee. Approximately 88% of the participants in our sample were coffee drinkers.
Conclusion
Whether you drink your coffee black or with milk, it doesn't seem to affect how warm or competent you seem to others.
Of course, the results can't speak to other outcomes of interest. It’d be interesting to test whether psychological perceptions like sophistication would be affected, or whether certain extravagant drinks like unicorn frappuccinos are viewed differently.
Methods Note
To test for significant differences in likability between our experimental conditions, we used an independent samples t-test. For statistically significant results, the difference between the averages of the two groups would be large, and the corresponding “p-value” would be small (p < 0.05). This indicates that if we were to replicate the study with the same population, we would likely obtain a similar effect. Additionally, we utilized OLS regression analyses with interaction terms to explore potential significant interactions between the main results and participant demographics, such as age and gender.
Additional details are available on our methodology page. Data and survey materials are available upon request.