[Penny1]

How about this: elves are less driven or controlled by their passions than men are...

Which is sometimes a good thing and sometimes not.

[GretchenEE]

Remember Galadriel's test? She certainly had the capacity to go for the dark side, just the same as the non-elf Gandalf, the man Boromir, etc. This doesn't answer whether elves could fall or not, but it implies that they could, since they could be tempted to do so.