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Evolution has certainly contributed to the establishment in our brain of a symmetrization process that helps us to identify an object oriented to the left (for example) when we saw it as it was oriented toward the right. This process leads to generalization and is fundamentally adaptive because, for example, a tiger is equally threatening whether it is seen in right profile or left profile. The symmetrization process was recently investigated in the macaque and the human brains, notably through functional resonance magnetic imaging. These investigations support the idea that orientation information is processed in very early visual regions, and leaves open the possibility that this information disappears at subsequent processing stages. In reflecting the development of the symmetrization process, the authors suggest that it should lead to the left-right reversal (also called mirror-writing) of the letters and digits of young children. Indeed, the process is very efficient until the age of three or four years, but becomes misleading when children write J, Z, and 3 (or not) for example. An empirical study involving 189 five- to six-year-old children supports the hypothesis that during the time needed for the operationalization of an additional mechanism of orientation's retention, the children direct the characters toward the right (at least in French culture). As a consequence, children who reverse the left-oriented characters (1, 2, 3, 7, 9, J, Z) the most are also those who reverse the other asymmetrical characters the least. This important result, and also more direct comparison, implies that some individual characteristics of the children, such as left-handedness, gender, or the socio-economic level of their parents, do not fully explain the mirror-writing of capital letters and digits.