This study explores the impact of positive emotions, especially happiness, on leadership styles through the innovative use of neuroscience. By measuring the affective responses of CEOs and senior managers during a major business event, the research offers new insights into how emotions influence leadership behaviours, decision-making and the classification of leadership styles. Traditional leadership research has focused on cognitive and behavioural aspects, but recent studies highlight the role of emotions in leadership effectiveness. Data was collected from 163 CEOs and managers who participated in a controlled experiment during the CEO Congress 2023. Participants viewed a 20-second audio-visual stimulus designed to evoke specific emotions and then completed a self-assessment questionnaire. Neuroimaging was used to measure brain activity and emotional responses in real time. The neuroscience-based results identified five predominant leadership styles, compared to eight styles classified by traditional surveys. The autocratic style was the most prominent in the neuroscience measurements, contrasting with self-reported data, where the mixed or participative style was more prevalent. Gender differences were also observed: men tended to be more associated with charismatic leadership, while women tended towards more participative styles.