Emotional Intelligence (EI or EQ) is the ability to recognize, understand, manage, and influence emotions—both your own and those of others. Originally popularized by psychologist Daniel Goleman in 1995, EI encompasses skills that enhance self-awareness, self-regulation, motivation, empathy, and social competence. Unlike IQ, which remains relatively fixed, emotional intelligence is learnable and improvable through deliberate practice. Research consistently shows that high EI correlates with better leadership performance, stronger relationships, improved mental health, and greater career success. The key insight: emotions are not obstacles to rational thinking—they're data sources that, when properly understood and managed, enable more effective decision-making and interpersonal connection.