'Potty Training' seems like a phrase with not much literal sense to it, but it's not that moot after all. Parents have to train the kids to make the bowel movement easy. Have you ever seen someone making the pee sound to help their kid urinate? Well, you are not alone! This trick is used worldwide with a healthy success rate.

So, how does the 'shhh' sound actually help kids pee?

Source: Babycenter

'Classical Conditioning' is the phenomenon responsible for this. 

Source: Babycenter

 We can understand this better by Russian Scientist Ivan Pavlov's experiment with dogs.

Dogs are known for creating a river of saliva inside their mouths when fed with meat slice. Pavlov in his experiment fed the dog with meat powder after ringing a bell. He continued it for a while, and as days passed, the dog would automatically secrete saliva once it heared the bell, even when there was no meat.

Source: Linkedin

This meant that the reflexes that occur unconsciously by the autonomic nervous system could be triggered by an external stimuli. Parents do the same thing when they make the 'shhh' sound when their kid is peeing. After a while, the toddler's brain makes the connect between the sound and the action of peeing.

So, the sound of peeing triggers the autonomic reflexes of kids and help them urinate!

Source: Kasjauns

It's not just the kids, even some adults get triggered by external stimuli. For example some people feel like urinating if they see any one doing so or on hearing the sound of running water, waterfalls, etc. 

Source: b'Source - Yahoo'

Next time if you want to mess with someone just 'shhh' around them until they have to stand up leave ;)