If you are interested how does the famous typographers' (including Erik Spiekermann! - sample below) handwriting look like, you can check it here - Handwritten Typographers
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I've wondered about this and found the samples very interesting. I thought there would be a lot more similarity between the handwriting and the font styles but they really run the gamut from tight & neat to multi-angular and flamboyant and the fonts each designer created don't necessarily match their own handwriting style at all.
To take this a step further, wouldn't it be fascinating to have those handwriting samples analyzed by an expert and find out how similar (or dissimilar) the results are, personality-wise? Maybe typographers can be pigeon-holed yet, CSI profiler style.