I have always thought that graphology was real until I read about it in the psychology textbook. Graphology is the psychological interpretation of handwriting. Before that, I have often wondered if my handwriting really reflected my personality. What did the direction of strokes indicate? Did the size of my letters matter? So I did some research, and found that graphology was not reliable at all.
Graphologists examine handwriting in terms of loops, dotted "I's" and crossed "t's," letter spacing, slants, heights, ending strokes, upslant pressure, downslant pressure, etc. They believe that these are useful to help understand health issues, personality, mental problems and even hidden talents. For example, tall letters show pride and ambition, and dotted "I's" and "t's" show discipline.
However, these claims are not supported when they were put to the test. In studies where participants copied writing samples instead of providing samples from thought, graphologists did no better than chance at predicting traits. One explanation for this failure is because graphologists may have based their interpretations on the content of participants' autobiographies rather than their handwriting. Although graphology is not reliable, it is still widely used. I think it is still popular because people often try to find ways to predict others' personality based on surface information, falling prey to the representative heuristic. When it comes to personality analysis, it takes more than one aspect, such as handwriting, for indication.
Here is a video showing how graphologists interpreted handwriting: http://www.youtube.com/watch?v=IL0R3mhqBv0