Help Us Read Your Mind...
For anyone who has not seen a mentalist before or ever tried to read a mind before; extracting and implanting thoughts is hard. Really hard.
It is highly likely that if you see one of us in the wild that we will be able to tell you ONE personal thought that is in your head but only one. Something that is unique to you but not to well guarded in your mind, your star sign for example. Here's the problem though, as soon as you see or hear that thought that you are saying in your mind repeated back to you your mind, consciously or subconsciously, will go on guard.
It's not everyday someone tells you what you are thinking and even if you want to help and participant it becomes increasingly difficult with each new thought we extract because of these psychological defenses your mind puts up. Because of this we find it better if there are multiple minds to read and if the information we are trying to acquire takes several forms.
If you have seen a mentalist before they may have asked someone to write down the word, image, name, phrase, question or any though they wish to think of because "this will prove to everyone later one that I got it right". The truth is, we don't actually think you are going to lie about your thought to catch us out or make us look bad. If anything we want proof if we get it wrong since people are so nice and want to see the entertainer do a good job they may lie and say we got it right when we didn't (it's happened before). No, the truth is we ask you to write it down to make it easier to extract.
Think about it, what did you do in primary school when you learned how to spell words, you wrote them over and over again until it becomes ingrained in your memory, until it was as clear in your mind as it was on paper. And that's what helps us do our jobs. If that thought is as clear in your mind as it is on paper or on screen or on a drawing board then it can come through much much easier.
An alternative reason may be that your mind has become too difficult to read for the reasons mentioned at the beginning and someone else needs to see what word you are thinking of in order for us to extract it from them instead. So write it down or type it and show it to them or whisper it very very quietly if you can.
You may see mentalists destroy or lose the slip of paper you wrote on moments after you write it because we trust you and as soon as you have done the act of writing and/or staring at your thoughts in a visual from (you could even google and image if you'd prefer) it gives us that little boost to make the performance go smoothly. And when we need to make our way around the party and entertain everyone with what it is we do we need to be as efficient as possible with each mind that participates. So please, clear your mind, and focus on your thoughts…