Conditioning of a child’s judgment about the fictional status of television stimuli: the role of knowledge and mental states understanding The research on children’s processing of television stimuli (Fisch, 2000; Fitsch, Huston, Wright, 1993) showed that on entering the world of television children discriminate different types of programmes on the basis of reality and un-reality of the message. The most important period to develop that competence is middle and late childhood. To explain the mechanisms of developmental changes that appear in that time it is important to estimate the cognitive conditioning of those processes. In the study presented in the paper children at the age of three, five and seven were tested with a view to find cognitive basis of their competence to judge unreality of a television message. The results showed that changes in the scope in children’s competence to judge fictional status of the television stimuli is related to the child’s theory of mind performance and the cognition of the material under evaluation (domain specific knowledge of the presented material)