Of course, it's called hunger my fren.
Yeah in certain cases I would say so, but I see it all the time with people taking completely unnecessary risks just for the heck of it or as something that they enjoy. Some of those people like peter said are free climbing places such as "El Capitan" (See image below) or base jumping, etc...I remember seeing a show (Can't seem to find it) about how certain people are just born with a "deficiency" of a certain hormone or whatever that makes them not have the same rational fears that the rest of us would normally have under those circumstances.