The Shang Dynasty changed the way rulers were chosen from father-son inheritance to brothers succession. This shift may have been influenced by the complex situation Shang Tang faced after overthrowing the Xia Dynasty. The researchers aim to understand why this change occurred and how Shang Tang dealt with it. They suggest that the centralization of power in the Xia Dynasty and the challenges faced by Shang Tang led to the adoption of brothers succession and polygyny as strategies for maintaining control.