That's one of the reasons why the Indo-European so quickly and triumphantly stepped forward - studying something themselves. Engage Indo easily. The second reason: in search of the Indo-European proto-language researched their ancestors. The problem of European scientists took not only as a man of science, but also personal. Reason Three: The significance of the problem. Everyone knew that studying something incredibly important: in countries inhabited by peoples who spoke Indo-European languages, the events took place, the most important for the history of mankind. Make discoveries and revolutions in culture that shaped the face of all modern civilization.