This research paper examines the application of the Paschalidis Tri-Anthropo-Type Model in lower secondary education. The Model was used with a class of First Year students of a lower secondary school in Northern Greece, in the context of the newly introduced subject "School Life and Social Life". The main aim of the application was to assist the students' transition from primary to secondary school and their adaptation to their new educational context. To conduct the study, seminar training material of the Tri-Anthropo-Type Paschalidis Model, questionnaires, comprehension exercises and experiential activities were employed. Questionnaires, structured interviews and qualitative observations were used for data collection. The results showed a smoother adaptation of students to the new environment after the intervention, greater awareness of self and others, improved selfconfidence, reduced verbal aggressive behaviours, a growing climate of trust and cooperation, as well as improvement of certain pupils' behavioural problems. Finally, the teacher recorded increased job satisfaction and reduced anxiety.