Why do we like some artworks more than others? According to one popular theory, the issue is "processing fluency." Compared to a Beethoven string quartet, we can mentally grasp a simple pop song much more easily, and this lack of exertion translates into enjoyment.

But if that's really true, why is it Beethoven's works are still being performed regularly after two centuries, where most pop songs are instantly disposable? Is it possible that we actually enjoy ambiguous art, even though it takes effort to decipher, and there is no guarantee we'll "get" what the artist is trying to express?

A University of Bamberg research team led by psychologist Claudia Muth makes just that argument in a newly published paper. In a small study in which participants evaluated paintings, the researchers found that "the higher the subjectively perceived degree of ambiguity within an artwork, the more participants liked it, and the more interesting and affecting it was for them."

What's more, this pleasure was not the result of the process of "figuring out" the meaning of a piece. To the contrary, a work's solvability "was not relevant for liking, and even negatively linked to interest" and emotional involvement.

"Artworks," the researchers write, "are not riddles to be solved via analytic steps."

The study, described in the journal Psychology of Aesthetics, Creativity and the Arts, featured 29 participants. They ranged in age from 18 to 41, and had no art or art history training. During two sessions, they viewed photos of 17 ambiguous 20th- and 21st-century artworks by such masters as René Magritte and Hans Bellmer.

The first time around, they rated each painting for liking, interest, and how strongly it affected them intellectually and emotionally. After their second viewing, they "rated each picture concerning its degree of ambiguity," described what specific elements they found ambiguous, reported "the strength of their insights" concerning the work, and rated the extent to which they considered its mysteries solvable.

The most striking result: "The higher participants assessed the ambiguity of a stimulus, the more they appreciated it." This was true of all the dimensions listed above, with ambiguity having the largest positive effect on "interest."

"A complete resolution of ambiguity is not necessary for the appreciation of an artwork," the researchers write. "In our study, subjective solvability of ambiguity was not significantly linked to liking, and was even negatively linked to interest and (emotional involvement)."

They note that participants reported flashes of understanding as they studied the work, which they found enjoyable even if they didn't unlock all of its secrets. "Insights during the processing of an artwork can be triggered by the ambiguity of an artwork without resolving it," the researchers write.

Muth and her colleagues concede that some people, as part of their basic personalities, have a lower tolerance of ambiguity. Perhaps for them, the fluency-equals-enjoyment equation applies. But quite a few others, it seems, get a lot of enjoyment out of works of art they don't fully understand — and don't especially mind when they're unable to resolve all of its riddles.

After all, if you walk out of an art gallery or concert hall stimulated but convinced there are hidden layers to what you've just seen or heard, that's a terrific incentive for a return visit.

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