When I am writing I focus on the content, the framing of sentence, the phrases, proverbs and words that I will be using etc. I don't think of the handwriting for most of the times.
So who decides how I write my g, j and y?
Who decides how large or small my writing will be?
Who decides what would be the space between two lines two words two letters? Who decides the slant pressure and all the other aspect of handwriting?
Of course, if I am writing then all these things will be taken care by me.
Simply putting a dot on a paper requires lot of coordination between various centers of the brain.
So a lot goes into your handwriting without your awareness.
Graphology is the science of studying the relations between the handwriting formations and our subconscious behavioral patterns.
It is an empirical science developed on the observations of handwritings and personality
It is really not known why it works but in general there is a good agreement between the handwriting and personality traits.
If the i dots in your handwriting are not well placed above the stem of the letter i then it means that you do not pay proper attention to your work at hand. Which is a fact. Had you been attentive towards the handwriting you would have placed the i dot at the write place most of the times.
So well placed i dots shows paying attention.
Similarly, many other traits are observed empirically.