In addition to imparting knowledge, a central task of primary school is to instill confidence in children regarding their own abilities. According to the Skill Development approach, measures aimed at improving performance can particularly strengthen a positive self-concept. Since reading ability is a fundamental cultural skill, this area was chosen to investigate how performance-related personality development can be supported through specialized training. The aim of this quasi-experimental primary school study was to examine the influence of the vocabulary-based reading strategy training "ESKIMO" on the development of self-related cognitions and motivations of third-grade children in reading. The effects on performance-related personality variables were determined for both the reading training group and the control group, which were operationalized through self-related cognitions and motivations in the area of reading (such as reading self-concept, reading motivation, or feelings of helplessness).