Crack open the weathered pages of an old book and what do you smell? According to research conducted by Matija Strlič and his team at University College London’s Institute of Sustainable Heritage, it’s likely to be “a combination of grassy notes with a tang of acids and a hint of vanilla over an underlying mustiness.”

It’s also likely that you’ll find the scent to be comforting, familiar, perhaps laced with nostalgia. Olfaction is linked directly to the limbic part of the brain responsible for memory and emotions so, when such an odor-evoked emotion surfaces, it’s because your brain has been triggered to summon childhood memories. But this scent taps into a larger collective memory that we share, says Cecilia Bembibre, a PhD student who worked with Strlič to analyze, doc...