The speaker, who authored the book 'Emotional Intelligence,' explains how the concept became popular and its significance in leadership. Emotional intelligence (EI) is crucial for outstanding performance and effective leadership, as recognized by the Harvard Business Review. The speaker outlines four domains of EI: self-awareness, self-management, social awareness, and relationship management. Self-awareness involves understanding one's emotions and their impact on thoughts and actions. Self-management includes handling emotions, maintaining a positive outlook, and staying focused on goals. Social awareness involves empathy and understanding organizational dynamics, while relationship management focuses on guiding, influencing, and inspiring others. Unlike IQ, EI can be developed at any stage of life, making it a valuable skill for personal and professional growth.