This article explains how people synchronize their thoughts through empathetic relationships and points out the elementary neuronal mechanisms orchestrating this process. The many dimensions of empathy are discussed, as is the manner by which empathy affects health and disorders. A case study of teaching children empathy, with positive results, is presented. Mirror neurons, the recently discovered mechanism underlying empathy, are characterized, followed by a theory of brain-to-brain coupling. This neuro-tuning, seen as a kind of synchronization between brains and between individuals, (...) takes various forms, including frequency aspects of language use and the understanding that develops regardless of the difference in spoken tongues. Going beyond individual-to-individual empathy and SYNC, the article explores the phenomenon of synchronization in groups and points out how synchronization increases group cooperation and performance. (shrink)