The Scientific Reason The Smell Of Cookies Makes You Feel Nostalgic

When you're baking cookies, do you follow a recipe you found online, like these foolproof and exhaustively tested chocolate chip cookies or these three-ingredient peanut butter delights (which are better than "real" cookies), or do you follow something older, like a recipe inherited from your parents or grandparents? Whichever you opt for, the smell can be transporting, taking you to a kitchen table from your childhood while an adult pulls a fresh batch of baked goodies from the oven. What is it about cookies that fills us with nostalgia for older, more innocent times?

It's actually a common experience called the Proust Phenomenon, so called because the French author Marcel Proust wrote in his multi-volume novel "In Search of Lost Time" about being taken to the past after eating a cookie (a Madeleine, if we're being specific). You see, the part of the brain that concerns our emotions — including our memories — is actually overseen by the olfactory bulb (that's your sense of smell).

So scent and emotions are closely enmeshed, and the same function that helps you remember a smell you don't like also helps you remember smells you do, including ones from your past that evoke strongly positive memories. If the smell of baking cookies was part of a warm and loving childhood, it makes sense that every time you get a whiff of them now as an adult, you start to feel nostalgic for those days.

For a huge brand like McDonald's, the Proust Phenomenon applies to effective marketing: Let the nostalgic scent of the restaurants and its food do the talking. Now that whole generations have grown up enjoying the Golden Arches as a mostly positive experience (oh, the thrill of convincing your parents to hit the drive-thru instead of eating leftovers!), McDonald's took a recent ad campaign in the Netherlands straight to people's noses. Yes, it actually created a billboard infused with the scent of its multi-ingredient-packed fries, letting the distinct smell waft out and hopefully trigger the memories of passers-by.

Brands may also use other specific flavors and their corresponding scents, as marketing campaigns play on to customers' nostalgic feelings linked to food. A flavor like cotton candy evokes visits to circuses, carnivals, and state fairs, while S'mores might remind people of family camping trips. And there is no scent more evocative of childhood than peanut butter and jelly to remind you of those ubiquitous sandwiches Mom would pack for your lunch in grade school. Brands are counting on customers opening the packaging, taking a deep breath to inhale the nostalgic smells, and making an instant connection with the food item that will have them buying it again and again.