text: During the Song dynasty, there was a clear division in social structure which was enforced by law. However, commoners could move up in society through the acquirement of wealth. Through passing the imperial exam or donating resources, people could enter the gentry. By the Yuan dynasty, there was a decrease in protection by the law for commoners. The gentry, however, were given more privileges. The Yuan dynasty also saw an increase in slavery, as the slave status became hereditary. The new policy for commoners at this time also made the various categories within the commoner status hereditary. The Ming dynasty saw a decrease in the number of categories for commoners, in comparison to the policy implemented during the Yuan dynasty. The three categories that remained were hereditary, making it nearly impossible to move between them. Gentry was also divided into two types. By the Qing dynasty, the peasants were seen as the most respected class. Merchants were far lower in status unless they purchased gentry status.
  During China's economic reform of 1978, the social structure in the country underwent many changes as the working class began to increase significantly. In 21st-century China, social structure is more reliant on employment and education, which allows citizens to have more social mobility and freedoms.
  Confucianism
  The teaching of Confucius (551 BCE – 479 BCE)  taught of five basic relationships in life:
  Father to son
  Older sibling to younger sibling
  Husband to wife
  Friend to friend
  Ruler to structure
  For dynasties that used Confucianism (not Legalism), the first noted  in the relationship was always superior and had to act as a guide and leader/ role model to the second noted , as the second person was to follow. For example: Father, 1st noted; Son, 2nd noted.