We're all familiar with the supposed prank: When you put a sleeping person's hand in warm water, he/she will urinate. This prank is quite popular in the US (or at least that's the idea we get from movies/tv shows), but I've never seen it done in real life nor would I humiliate someone by doing it to them. The question is thus, is it true and what causes it.

Yahoo gives the following answer:


Source

So, is there any truth to this prank, and if so, what is the real reason, as I don't really bite the "power of suggestion" theory.

I don't know what actually causes it. Maybe an involuntary reaction, but here is a pic that seems to prove it true
external image

Not wanting to be a stick in the mud, but doesn't this particular picture look a bit odd? Shouldn't the ... err... wetness go down to the bottom towards the bed, and not "up and right" towards his knee?

But overlooking the technical issues, yes we've seen countless such pictures, but is there scientific "proof" or explanation?

Well the bloke does look pretty wasted, and i guess it could depend on where he was, ahem, dressed, as to where the mess deposited itself!

I don't know about any scientific proof, I've only ever seen pictures and 2nd or 3rd hand stories about it

Guess the only way to know is if one of you test it,
Im sure you have a friend that could put your hand in the water while you sleep


Then you can come back and update us if this is true or not,


all in the name of research of course

Well... Err... See.... Uhm...

Hmm. Ah.

I can't scientifically observe the experiment if I'm asleep, now can I?

OOPS

When I was 15 a mate and I tried this on another sleeping pal. He woke up and slapped us both, so I'm sorry, this is all I have to offer on the subject.

I sometimes wet myself whilst in a seizure, and other times if I get too drunk.

I once had a dream where I did it with a can of Tuna. It was quite an erotic dream.

So, um, no.

I did this once to my older sister while camping and it did work. It was quite humorous although she wasn't happy and kicked my arse big time for it. It was well worth it though.

This thread is great, and to pay it forward I'm going to try this three nights in a row for you guys, starting tonight. Right before bed for the next three nights, I'll drink one pint of water, and my brother (more than willing to help out) will put my hand in warm water at a different time each night. I'll keep you all posted.

After the first night, I cannot confirm that this prank works as I did not wet myself last night. My hand was placed into water ~2 hours after I fell asleep. Will try again tonight.

greatpiino
lol you are a brave guy! look forward to the following results lol,

All in the name of science hahah


Way to go you for giving it a go,

Greatpiino... Your braveness is an honour to science community. Hopefully the scientific circles will hear of your ventures and maybe give you a Nobel Prize for Physics/Medicine/Science... Good luck!

I've seen this trick tried a few times in barracks and on board ship.
Even when the person was passed out drunk or totally exhausted, I've never seen a sailor wet himself.

(Well, not with the warm water trick, but fear will do it sometimes....)

After the second night, I must once again dissapointingly report that I did not wet myself. My hand was placed into water ~3.5 hours after I fell asleep. I have to say, I've never been more upset at NOT pissing myself. Come to think of it, I don't remember being all that upset the last time I did it which was St. Patty's day 2003, but I don't think anything could have upset me that night. Oh well, one more night to go, then I give up.

No, it didn't work again. I'll try one last time next time I'm drunk, maybe I'll have a better shot then.

Gemwolf:
Right on Bro,we all knew this rumor in the early 90s and we tried it on one of our mates on a school trip.He went to sleep and we got a bag of warm water and popped his hand in.
He didn`t commit the act,nor did he wake up...but he did acquire a strange expression which everyone laughed at for ages.
Fun but silly.

So that's it then? It is an urban legend. It's funny actually - for it's the first time I've seen someone disappointed that he didn't wet himself.

@ Silcone Synapse
I can just imagine what kind of expressions appears. I know I would have a PO-ed expression if they tried it with me.



Maybe we should do this a bit more scientific, seeing that we've got a willing test subject... Maybe the temperature of the water is important. Greatpiino, could your bro maybe try different temperatures of water?

Gemwolf, just let me know exactly what you want me to try. I mean, I have to go to sleep every night no matter what, so it makes no difference to me. And my brother is delighted at the potential of making his twenty-four year old brother wet himself, so game on. I definitely do want to try it again the next time I happen to be drinking...I can recall a couple exceptionally intoxicated evenings when I almost had an accident while awake, so I bet if we try this when I'm in that state it's almost guaranteed to work. I don't drink very often though, but maybe next weekend. In the meantime I'll keep experimenting.

You can try different degrees of warm water. Let’s say 15 minutes before the experiment your brother takes warm water from the tap, put it somewhere to cool down, then again (in a different container) at 10 minutes before the experiment and again 5 minutes before the experiment. He can then use all three different temperature water containers to re-do the experiment.

It would be ideal if you have a thermometer to see what the temperature differences between the containers. I’d say a temperature difference of 5 degree Celsius per container would do? Remember that the hottest you want to go is 49°C (120°F). Anything hotter and you’ll burn.