Abstract. This article presents the main results of the empirical study on the cognitive
complexity of the semantic space and features of psychological defense mechanisms among persons with different levels of stress. The following methods were used as methodological tools: the psychological stress scale PSM-25 (R. Tessier, L. Lemyre, L. Fillion, adapted by N. Vodopyanova); the repertory grid technique by G. Kelly; the Life Style Index (LSI) methodology (R. Plutchik), adapted by L. Wasserman. As a mathematical method, the Mann-Whitney U-criterion and Fisher’s angular transformation were used. The research confirmed the hypothesis that subjects with different levels of stress will have different cognitive complexity indexes and types of psychological defense mechanisms. Subjects with a low level of stress had a high index of cognitive complexity of the semantic space, they have more pronounced defense mechanisms such as intellectualisation and denial. In subjects with a high level of stress, a low index of cognitive complexity and the severity of such psychological defense mechanisms as repression, projection, and regression were revealed.
Keywords: cognitive complexity, cognitive simplicity, psychological defense mechanisms,
stress level, distress
