Maybe it's really about better decisions when not dehydrated.
When you gotta go now, you don't want to be piddling around with the researcher slowly counting out $16 in pennies and signing payment forms in triplicate when you can run to the potty right now and pick up the money later.
Better decisions? Maybe in controlled lab rat conditions however I distinctly recall standing on the wing of the airplane while it was still rolling after landing and I got off before the plane stopped moving. The last couple thousand feet was all turbulence into an obstructed mountain runway. The plane was left sitting in the middle of the runway with all the switches on with the mixture pulled out while we were watering the bushes.