Communication for Social and Behaviour Change has evolved significantly over time, reflecting shifts in development thinking, public health strategies, and understanding of human behavior. In the early decades of development communication, the dominant approach was Information, Education and Communication (IEC). IEC emerged in the 1950s and 1960s alongside modernization theories, which assumed that lack of information was the primary barrier to development. The central idea was that if people were provided with correct knowledge through mass media campaigns, posters, pamphlets, and public announcements, they would adopt desired practices. IEC was largely top-down, expert-driven, and message-oriented. Communication flowed in one direction from authorities to communities. The focus was on disseminating facts about health, sanitation, family planning, or nutrition, with limited attention to cultural contexts, social norms, or structural barriers. By the 1980s and 1990s, it became evident that knowledge alone did not automatically translate into sustained behavior change. Many IEC campaigns increased awareness but failed to achieve long-term adoption of healthy practices. This led to the development of Behaviour Change Communication