Caffeine is added to soft drinks with an eye on its addictive potential. Researchers found that the amount of caffeine added to an unfamiliar beverage was correlated to how much teenagers liked that beverage.
"Soda manufacturers claim that caffeine is added to their products to enhance flavor. However, the majority of people cannot taste the difference between caffeinated and non-caffeinated soda. This led us to suspect that caffeine may be added to beverages for other reasons," said senior author Jennifer Temple, Ph.D. "We hypothesized that adolescents who repeatedly consume a new and unfamiliar drink that contains caffeine would like that beverage more over time, but that adolescents who drank an unfamiliar beverage without caffeine would show no change in their preference."
To test this theory, adolescents aged 12-17 visited the laboratory multiple times. During each visit, they sampled an unfamiliar soda drink and rated their liking or preference for that beverage. The sodas contained varying amounts of caffeine, and the caffeinated or non-caffeinated versions were varied across participants. Over repeated testing days, participants increased their liking of the soda with the highest levels of caffeine, whereas there was no change in preference for sodas with low or no caffeine.
These results are consistent with prior evidence that teens prefer sodas that contain caffeine compared to those that do not, and newly demonstrate that this preference emerges as a learned behavior.
The study is to be presented at the upcoming annual meeting of the Society for the Study of Ingestive Behavior (SSIB), the foremost society for research into all aspects of eating and drinking behavior.