This book is a scientifically based work rich in psychological and emotional content that will undoubtedly serve as a reference in many future studies in the area of human behaviour and teaching-learning methods, taking into account the psychological behaviour of teachers. It investigated the nature of dissatisfaction among 5th to 9th grade teachers in four schools, 61 teachers, mostly female, aged between 21 and 62. This is in line with the objectives of the research, which sought to identify the correlation between teacher dissatisfaction and the age range of the clientele between 10 and 14 years old. The results are surprising, signalling poor management of affective content on the part of the teachers, with 33% pointing to feelings of discouragement as a consequence of job dissatisfaction due to student disinterest. It opens up avenues for future research, considering the three-dimensionality involving schools/teachers/families. The book is based on research for a Master's Dissertation in Human Resources Psychology and Knowledge Management, plus clinical case reports and professional experience.