People judge pills' effectiveness by appearance alone, study finds
The old adage 'you can't judge a book by its cover' can be extended to pills, too. It turns out that people set up expectations about how well they think a pill works and how they think it will taste based on outside appearance alone.
The research is reported in the journal Food Quality and Preference.
Researchers conducted two online experiments to find out expectations of pills of differing colors and shapes, and they found certain judgments were consistent across international lines.
In the first study, 97 participants from the U.S. viewed 21 images of pills in seven different colors and three different shapes: round, oval and diamond. Participants rated each pill on the expected level of bitterness, effect on alertness, and how well they believed it could combat headaches. The shape of the pill was rated on how difficult participants believed it was to swallow.
Overall, participants believed light blue tablets were the least bitter. Red and light red tablets were rated as the most mentally stimulating. People believed white pills would be the most effective at treating headaches, and that light green ones were the least effective. Diamond-shaped pills were rated as the most difficult to swallow.
In a second experiment, the questions were repeated to a group of 337 participants from China, Colombia and the U.S. This time participants were told to assess pictures of pills in a greater variety of colors.
Results from the second experiment revealed that different cultures have the same perception of certain pill colors and shapes, as well as some differences. For example, all three cultures believed that white tablets were the best for headache pain and diamond-shaped pills were the most difficult to swallow.
Interestingly, the color of the tablet influenced how difficult the Chinese participants believed the pill would be to swallow. (This was not the case for the other two countries.) People surveyed in China rated red and blue pills as the hardest to swallow.
"These findings clearly demonstrate that the differing colors and shapes of pharmaceutical pills set-up significantly different expectations which likely play an important role in terms of people's subsequent experience," the report states -- something drug manufacturers may want to take into consideration.