We can consider the thematisation of a situation that is common and relevant among small group members as a result of a communicated shared experience among the members of a group. On the other hand, thematisation of a generally well-known, but less experienced situation, follow a rather more general core of social representation of an adolescent and a middle-age person. Method and sample There were three groups of research subjects - classmates (65 altogether), aged from 16 to 17. Every class-group came from different grammar schools in the city of Brno. There were not any interactions among participants during examination. The participants were asked to solve two problem situations. The first situation showed a person (man/woman) lying on a street, who may be in a need of help. The second situation presented a person (man/woman) wanting to get a job that is very important for her/him. The two situations were selected under conditions as follow: Adolescents should be familiar with both of these situations but they have to have different factual contact with one and the other. These should be applicable to different social-class groups or age groups. The first need of help dilemma shows a situation, which is well-known but unusual in everyday life. It is dealt with more in media than experienced in a life. On the other hand, the second job-seeking situation is more common among students. It shows competition in achievement of a position or status. We expected that many aspects of competitive job-seeking situation are more frequent in everyday life of grammar-school students and it is more communicated and experienced among them than the out-group helping situation. Each of these three groups of classmates was further divided into three subgroups by chance. The task for these subgroups differed in a person who should act in these two problem situations. Members of the first subgroup described their own possible action; members of the second subgroup described action of their friend and finally members of the third subgroup presented what they would expect as an action of a middle-age person (man/woman). We have applied the method of thematic analysis (Tyrlik, Macek, 2002) to analyze written solutions of situations. All solutions were analyzed in order to find the main thematic dimensions of social representation, which create a background of respondents understanding of the situation. Our results support our assumption that the core of social representations and their peripheries participate on individual representations differently, depending on both subjective familiarity and in-group familiarity of the situation. The communication of common experience, obtained within familiar and relevant situations, takes the thematisation away from the general core of social representations and introduces variability to their periphery.