Well, a cognitive Psychologist (can't remember who) found that mental fatigue results in worse outcomes. If you burn yourself out with studying, a lot of your studying will be inefficient and your test results may not be as good as they should be.

Taking a break every so often is important to reduce the mental workload. It's also important to note that during Finals week, you should not be trying to quit smoking or start a diet. Those increase mental workload and can result in fatigue.

So yes, have fun. Just don't let it get in the way of your studying. a proper balance is all you need. like right now, I'm studying, but I take a load off, check facebook and createdebate, and then get back to work.

For better results, probably. For example, here's the conversation I had with my Maths teacher when I only got a B on one of my papers. (He's African, so imagine it read like Joseph Kony, or something).

"Rhys, why you no get an A?"

(What I should have said)

"Well sir, I spent far too much time dicking around, playing croquet in the pissing rain, drinking acidic pond water, ruining one of my friend's innocence by reading him all the puberty and sex books in the local library, and watching his face screw up when I draw him a lovely diagram of the male genitalia".

(What I actually said)

"Pff... Dunno"

So yea, if you want better results, avoid fun. But fun is just so... fun.