Psycho1 Res (1982) 44:165-174 Psychological Research © Springer-Verlag 1982 Do We See What Makes Our Script Characteristic - Or Do We Only Feel It? Modes of Sensory Control in Handwriting All Zimmer Westf. Wilhelms-Universit~it Miinster, Department of Psychology Summary. How does a person produce handwritten letters which are both leg- ible and also show an individuality of script? Three production control models are proposed: 1) Visual control, 2) Kinesthetic control, and 3) Parallel Kines- thetic and Visual control. In Experiment 1 24 subjects wrote text samples by hand under normal lighting, reduced lighting, or in complete darkness. The subjects addressed the samples to themselves, to close friends, or to other stu- dents. The handwriting did not degenerate under the reduction of visibility if the subjects addressed the samples to themselves, but it did undergo marked changes if directed at someone unknown. This result rules out the visual con- trol model. In Experiment 2 the same subjects were asked to answer questions about the characteristics of their own handwritten letters while holding an image of the letter in mind. There were four types of imagery instructions: sub- jects were told to form either 1) a static visual image, 2) a dynamic image, 3) a kinesthetic image, 4) a combined kinesthetic and dynamic visual image. Sub- jects were able to answer questions about their handwritten letters more cor- rectly with the fourth type of imagery instructions, suggesting Parallel Kines- thetic and Visual control of handwriting, the third of the prol~3sed control models. A closer examination of the results of Experiment 2 reveals that the control processes are interactive; the idiosyncratic letter forms which make up the individuality in handwriting are controlled exclusively by kinesthetic in- formation. One of the many puzzling aspects of cursive handwriting is that despite the high vari- ability between people's scripts it is possible to decipher an individual's handwritten messages relatively easily. Equally puzzling is that despite the high variability within a person's handwriting a writer can be identified through his or her script with high reliability. Any theory that attempts to elucidate the processes underlying the produc- tion and recognition of script has to identify invariances and transformations which can account for the variability as well as for the communicability of script. Visual feature analysis, which has been successful in the identification of printed letters (see, 00340--0727/82/0044/0165/~ 02.00