viva la vida: I think you can see a bit of how the person really is by his/her handwriting style. In this particular case it seams childish to me... and this person is ruling over 8 million people.
Graphology (handwriting analysis) is a controversial area and the main criticism is that it lacks validity.
However, I couldn't resist and I just had to find out why Jackson made his "O" like he did. The pen movement is odd. So...I did some reading...
http://www.high-tech-old-school.com/upload/handwriting%20quickreferenceguidegc.pdf
And this is what it said about an "O" made in that way:
Secretive
Circles within circle letters on the right hand side. The larger the inner loop is, the more secrets this person will withhold from others. If the inner loop is huge, this person will try to avoid giving you a complete answer.
What I see when I look at Jackson's signature, is a person who has had little education. His signature is childish and odd for an adult man.
His signature is probably the only thing that he picks up a pen for - he probably does very little, if any, actual long hand writing. Making letters in the way that he did for his signature would be slow and tedious for any length of writing. I guess that is why he has "helpers"...the guys who do the writing for him and...you know, for turning pages and pouring water.