The claimed benefits resulting from the tours:

>The surveys included multiple items that assessed knowledge about art, as well as measures of tolerance, historical empathy and sustained interest in visiting art museums and other cultural institutions. We also asked them to write an essay in response to a work of art that was unfamiliar to them. These essays were then coded using a critical-thinking-skills assessment program developed by researchers working with the Isabella Stewart Gardner Museum in Boston.

They've demonstrated that exposing children to art makes them care more about art. Having said that, the title of the article really seems like a stretch.