To figure out what is really going on, the researchers found that the TAS2R genetic variant associated with higher sensitivity to caffeine was more strongly associated with increased intake of caffeinated than decaffeinated coffee. This association explained, biologically, the findings about higher bitter sensitivity being related to higher coffee intake from the survey. The conclusion—that those of us with heightened sensitivity to the bitter taste of caffeine learn to associate it with psychostimulatory reward—is a remarkable and counterintuitive finding.
