10 Cool Facts About Olfaction

We all have a sense of smell, and we all use it constantly, whether we realize it or not. Scents and smell are two of the most important yet often overlooked elements of everyday experience. Want to learn a few truly amazing facts about the things your nose knows? Then just keep reading.

• Everyone has a unique "smellprint". No two people smell things the same way because each of us has scent blind spots, meaning specific odors we can't pick up on. So that room spray that smells like cupcakes to you and like creamed corn to your friend? You're both right.
• You really can smell fear. You can also smell happiness and sexual arousal, as long as the person you're smelling is a close romantic partner.
• Women generally have stronger senses of smell than men. So it's not surprising that you know the milk's gone bad long before your guy roommate does.
• Good smells make you happier. Smelling a fragrance you perceive as pleasant has a profoundly positive effect on your mood. So if you love vanilla, keeping a little scented oil on your desk can help lift you when you're down. The same goes for citrus, jasmine, or any other scent that makes you feel contented.
• There are fewer scents than you think. Some researchers hypothesize that there are only seven primary odors: musky, putrid, pungent, camphoraceous (like mothballs), ethereal (like dry cleaning fluid), floral, and minty.
• Pregnant women's weird food cravings may be because of their senses of smell. Because your nose is hypersensitive when you're enceinte, you develop an abnormal sense of taste, leading to bizarre cravings like pickles and ice cream.
• You actually smell with your brain. Not your nose, as you might assume.
• Scents can cue memories. Most of your scent memories, however, come from the first decade of your life, unlike visual or other sensorial memory types.
• Men can smell when women are ovulating. Both sexes can smell whether other people have major histocompatability complexes (MHCs) different from their own. This is interesting because mating with someone whose MHC is not too like your own creates offspring with hardier immune systems.
• Humans have 350 functional olfactory receptor genes. Mice have 1,300.