Urination Reflex

[CutthroatX]

When you put a sleeping person's hand in warm water it causes them to wet the bed.

I was wondering what the mechanism is that causes this to happen, and I want to know what good it did in the realm of survival.
What was the point of having this urination reflex?

[mith]

You should check your premise before proceeding i.e. try it out to see if it actually works.

[CutthroatX]

I know that whenever I take a warm shower it makes me want to go to the bathroom really bad. I figure that is proof enough for me.

[canalon]

I know that whenever I take a warm shower it makes me want to go to the bathroom really bad. I figure that is proof enough for me.

Then your standard of quality are quite poor for proofs, because comparing both is quite a stretch.

And reflex are not necessarily useful for survival, or for anything. They can just be there as a side effects of another thing that is actually useful.

[biohazard]

This doesn't actually answer to the question about a hand in warm water and wetting a bed, but what I know is that some staff in a clinical lab where I used to work used warm water on baby boys in order to make them pee, because otherwise collecting a urine sample from a few months old is pretty tricky (they don't pee on demand ) - so they just ran a bit of warm water on the kids' pecker and voilá! You got your urine sample in no time

Now, what I don't know is that if you'd put the baby's hand in warm water instead, would he pee - anyone got a fresh new baby boy and wanna try out..? In the name of science!