That clean smell.

[Mako]

There's some things that naturally smell clean to us. Pine. Bleach. Freesias.

And there's some things that smell dirty to us. Rotting meat. The ringpiece of someone who's missed a couple of showers. Orlando.

How much of this is innate, and how much is learned? We know that the smell of feces is deliberately objectionable to stop us from being near it. But do we know the smell of clean things instinctively, or do we pick it up from our parents?