"Overthinking" is probably a misnomer. It's more likely endless dithering that is happening. If I remember correctly from a Tests and Measurements course in college, your first choice of the answer to a question is more likely to be correct than stopping and dithering over it, maybe changing your answer 2 or 3 times.

It's a matter of intuition vs. dithering over too little information. Of course, your best bet is to study thoroughly for the test. Burn some midnight oil.

When it comes to interpersonal affairs, dithering doesn't help. If your ethics are firmly in place and you know the facts of the case, your intuition about what should be done is probably not too far off the mark.

Should intuition be trusted? It's much better to know what you are doing and not have to depend on seat-of-your-pants guesses. A lot of the time, we do not have enough information and we do not really know what the hell we are doing. This isn't a function of stupidity. We might be thrust into the position of having to make an important decision for somebody else -- without knowing all the facts of the case. Maybe we guessed wrong with the best intentions, and caused more problems down the line,

That's a risk we might have to accept.