I like to believe that Lord ganesha is one of the most important Gods of Handwriting/Graphology.
Here is a story of Mahabharata. Maharsishi Vyasa thought of writing this beautiful realistic epic: Mahabharata. He requested Ganesha to write down the verses as he goes on composing it. The then young Ganesha put his condition that Vyasa should not stop in between and keep telling him the verses continuously. Vyasa agreed with one condition that Ganesha should write only with full understanding of the verses. Ganesha too agreed to this condition.
Maharishi Vyasa was smart enough to put this condition. The verses were so meaningful that Ganesha required some time to understand each of them as he wrote. This slowed his writing. Vyasa could borrow that time to compose next verses. There came a moment when Vyasa was so fast that Ganesha could not find a replacement for his broken feather pen. To keep his promise of uninterrupted writing Ganesha broke one of his tusks and used it as a pen.
Let me explain why He is the God of Handwriting.
While he was writing, he was understanding what he was writing. And what was he writing? Mahabharat, the epic that is about so many personalities, so many human behavioral traits. In fact, it is said that the Kauravas are our desires and Pandavas are our five senses under the control of the Lord Krishna.
Each character in Mahabharata, big or small, is a symbol of some human behaviour. Mahabharata is full of emotions. I must also mention the authority of Maharishi Vyasa. His name itself literally means the diameter. The diameter of a circle encompases everything. So his epic also covered all types of people and personalities, from Bhisma to Abhimanyu and so many more. Vyasa also means the compiler. Maharishi Vyasa has compiled every aspect of human nature in Mahabharata.
And Ganesha was understanding each and every word of this knowledge while writing. Ganesha demonstrated his authority in handwriting and understanding personalities both at the same time. This is the reason I like to believe that ganesha is the God of Graphology.
Just imagine this, Maharishi Vyasa is dictating verses of Mahbharata to Shree Ganesha where he is telling him about Sanjay giving a running commentary to Dhritarashtra about the first day of war on Kurukshetra wherein, Krishna is enlightening Arjuna by telling the Bhagvad Gita.