THAT'S THE WHY:If there's a gag that never fails to raise a chuckle from small kids, it's to hold up a sock and pretend to faint at the smell.
The comedic value is a reminder that even at an early age, we realise that feet can pong.
But why? It basically boils down to two things: sweat and microbes.
Each of your feet hosts thousands of sweat glands, and while their output doesn’t initially smell like foot odour, when bacteria feast on it you can start drawing the stink lines.
Wearing shoes and socks tends to trap sweat and offer bacteria a cosy environment and so compounds the issue.
Researchers at the Hohenstein Institute in Germany have been taking smelly feet seriously – they conducted experiments where participants walked around for hours in various combinations of shoe and sock types, then an “electronic nose” gathered data and compared it to the reactions of human sniffers.
They reckon their system can help inform manufacturers about whether a particular textile or design is likely to encourage whiffiness.
But the most eye-catching paper I came across on this subject was one looking at the ancient practice of using “shoe smell” for someone experiencing an epileptic seizure.
The 2008 paper in Clinical Neurology and Neurosurgerydid not endorse the purported remedy of bringing a shoe near the person's nostrils, which it said persists in some developing countries in the east.
But the author suggested a possible explanation: that a strong smell might play a role in desynchronising cortical activity and dampening down a seizure. Not one to try at home.
