Everyone loves music. That’s the presumption behind countless pop songs: Pharrell Williams’ “Happy,” the current most popular song in the country, exhorts listeners to clap along if they’re feeling happy. But the notion also informs more serious thinking about music. Its popularity has been so universal that scholars focused on the evolutionary reason for its development. Likewise, the absence of enjoyment of music has been treated, in scholarly literature, as a physical or mental defect.

That’s why the prosaic-sounding main takeaway from a newly published study—that some people just don’t like music—is in fact dramatic. Participants who reported to not enjoy music still tested healthy in mind and body—which challenges the notion that music is some universal characteristic. If happy healthy people can express no connection to music, then the explanation that music came about through evolution just became a lot more controversial.

Here’s how the project worked: Researchers from the University of Barcelona and the Bellvitge Biomedical Research Institute ran two separate experiments on three groups of participants—people who had previously been tested for high, average, or low sensitivity to music.

In the first experiment the participants did two tests. In the first, they had to rate the degree of pleasure they felt when listening to music. In a second, they responded to a target in order to win or lose real money. The results were pretty clear: people who had previously reported low sensitivity to music demonstrated no autonomic responses to the music, despite normal musical perception capacities. However, they did respond to the monetary reward game—which demonstrated that their indifference to music wasn’t connected to an abnormality in their neural reward network. Their brain circuits were perfectly healthy, despite the lack of response to music.

Another experiment, performed a year later, was more basic. Participants were asked to rate the degree of pleasure they experienced from food, sex, drugs, exercise, money and music. The low sensitivity group consistently reported low scores of pleasure when it came to music. But on the other items, they reporting feelings that were similar to everyone else.

The researchers describe this reaction to music as musical anhedonia and say their work acknowledges, for the first time, the existence of a group of healthy people who don’t feel rewarded when listening to music. “What our findings reveal is not a particular preference for one class of stimuli over another—one person may enjoy opera, while another may find it boring,” the authors write. “But an inability to derive pleasure from an entire domain, music, which the vast majority of human populations do find pleasurable.”

Unsurprising? Maybe, but it goes against previous research that asserts music is a significant part of all human existence, a factor of our lives that came about as an evolutionary advantage. The researchers behind this study in particular hope that by continuing to study individuals less-than thrilled about music, we can learn more about why it is so rewarding to the majority of the population.

In the meanwhile, if you’re curious about your own music sensitivity you can take the quiz used for this study here