This document discusses happiness at work and evidence-based interventions to increase happiness. It defines happiness at work and lists reasons why happy employees are beneficial for organizations. Research shows the top factors that make people happy at work are friendly colleagues, enjoyable work, a good boss, work-life balance, and varied work. The document discusses different happiness interventions that are evidence-based, such as cognitive behavioral therapy, physical activity, optimism, gratitude, and mindfulness. More research is still needed but interventions like HeartMath that target the emotional brain directly may be more effective than those only targeting the neocortex.