Could your house be smelling a little... err... ripe right now without your even realizing it? Evidently, the answer is yes. Turns out, "nose-blindness" or sensory adaptation is a real thing and here's the fascinating reason it exists.
According to an excellent article over at Science of Us, our noses are actually very savvy tools that allow our brains to gather information about the world around us. When a smell enters your nose, it sends a signal to your brain to be identified. If your brain decides the smell is not a threat, then you don't need to waste any more energy on that particular problem and your nose's odor receptors begin to switch off.
Cognitive psychologist Pamela Dalton says this all happens very quickly — in about two breaths. That's why you will perceive a smell the strongest right away and eventually, not at all. This phenomenon is no doubt a holdover from our ancestors who needed to be able to discern subtle smell changes in their environment as a safety measure.
When it comes to your home, chances are there aren't any particularly bad smells (as you would hopefully have taken care of those when you noticed them), but every home does have a unique odor which its residents have long since stopped identifying. Dalton says, "People go on vacation and come back and say, ‘Oh, it’s so musty in here — I’d better open some windows!'" but that musty smell is most likely always there, you're simply noticing it because you've been away.
There's not a lot do do about this particular evolutionary trait; we seem to be more or less stuck with it. Interestingly, it's worrying that your space might smell which might actually make you less nose blind because it's linked to fear. Dalton found that people who associated smells with negative feelings toward something adapted more slowly. Just another quirky trait in our big, bad brains.
Read more at The Science of Us.