This study is examining the mood in which young people express their sensitivity to a literary idea in writing. The context is the 19th Century Naturalism. An earlier reported study could show that persons, when confronted with evolutionary determined literary texts, are either consistent in their way of approaching those tasks during three years, or are open to change. The latter strategy has been interpreted as sensitivity to instruction. In the present study, the concept of sensitivity was redefined to mean temperament. Instead of describing temperament the classical way, two persons’ written discourse has been treated with Perspective Text Analysis (PTA/Vertex) and represented through a graph program. The study could show that the two persons’ different conceptual structure got its flow dynamical counterpart in the evolving 3D-shapes. Therefore the shapes could be given a terminological description as geometric expression of temperament.