The Great Leap forward was Mao's idea to bring the nations economic development.
By 1957 peasants already were forced to work in agricultural cooperatives.
Even more exaggerated targets were subsequently presented, and then frequently revised upward, for steel, grain, cotton and other products.
They built backyard furnaces for iron and steel and worked together on massive building projects, including one undertaken during the winter of 1957-58 in which more than 100 million peasants were mobilized to build large-scale water-conservation works.
The grain reserves were exhausted and the famine had begun.
During the period of the Great Leap famine, scholars have estimated that somewhere between 16.5 million and 40 million people died before the experiment came to an end in 1961, making the Great Leap famine the largest in world history.
Agricultural performance improved dramatically and gave momentum to the reforms under Deng.
The memory of the famine reinforced the important role peasants play in China's development, Yang said. That memory also has undermined the appeal of central planning in rural policy-making.