In recent decades, the manifestations of the toxic leadership phenomenon and its aspects that generate negative consequences for employees, society, organizations, and even national outcomes have been increasingly examined in scientific publications and the public sphere. Toxic leadership, as a specific construct with a cumulative impact, encompasses a wide range of negative leadership behaviors from overt aggression to more subtle, non-violent actions (Hilaluddin et al., 2020; Gandolfi et al., 2022; Alanezi, 2022; Younis et al., 2022, Semedo et al., 2022; Octavian, 2023; Elbers et al., 2023; Modise et al., 2023 etc.). In the education sector, toxic leadership is recognized as a rapidly growing dilemma encompassing harmful leadership behaviors, destructive behavior patterns, systematic repetitive dysfunctional traits, and toxic characteristics. This type of leadership demoralizes subordinates, undermines their personal and creative capacities, loyalty, productivity, and team atmosphere, negatively impacts organizational culture, and increases staff turnover rates. The formulation of the scientific problem is aimed at answering the problematic question - what are the trends of toxic leadership expression in educational institutions? The aim of the research is to analyze the constructs of toxic leadership in different types of educational institutions.

The quantitative research strategy is based on a positivist philosophical paradigm and deductive logic of the research process. The empirical methods of data collection used in the master's thesis were: traditional/narrative analysis of scientific literature; written survey using a closed-ended questionnaire to reveal the characteristics and expression of managerial leadership from the employees' point of view. Eight dimensions of the toxic leadership construct were identified for the development of the research instrument: dark charisma, narcissism, malignant hostility, bullying, psychopathy, petty tyranny, authoritarianism and machiavellianism. Data were processed by applying descriptive statistics methods, Cronbach α calculation and comparison of the research data between different groups using the Mann-Whitney U test to determine the significance of the differences. 314 respondents from one region of Lithuania took part in the survey, including 155 pre-school and 159 general education teachers.

The empirical research revealed the dominant constructs of toxic leadership, the main dimensions, attributes, criteria, the interconnections of the toxic triangle system, which are reflected in the conceptual model of toxic leadership, as well as the trends of toxic leadership expression in pre-school and general educational institutions from the pedagogical point of view. A comparative analysis of the expression of the toxic leadership constructs revealed that the dimensions of malicious hostility and bullying, psychopathy and petty tyranny, and authoritarianism and Machiavellianism were more prevalent in general education institutions than in preschools. The study shows that a manager's toxic, anti-moral values, coercive supervision, excessive control, and reproaches to subordinates’ cause stress, influence employees' low self-esteem, and weaken work efficiency and productivity, dyadic relationships, and organisational effectiveness.

Keywords: Leadership, toxic leadership, educational institutions, quantitative study.