Tea drinking in China is not only for the purpose of health and taste but is also a symbol in society. It is often used as a sign of respect with younger generations offering the elderly tea or colleagues pouring each other a cup. It is also used when apologizing as pouring tea for someone who you have wronged can represent regret and submission. Tea plays a huge part in the fabric of family in China, with it being used for all family events. On Sundays, Chinese restaurants and tea houses are full of families sharing pots of tea. At traditional weddings, both the bride and groom kneel in front of their parents and serve them tea as a way of expressing gratitude and a traditional tea ceremony is used to bond the couple's families together in a formal social event. The couple would serve the tea to all the family members who would drink the tea to symbolize the acceptance of the bride or groom into the family. Even in the rapidly modernizing China, the preparation, serving and communal drinking of tea still has its place at the centre of Chinese social bonding and lifestyle.
Given that the pouring of tea in China is considered a show of respect and bonding amongst friends and colleagues, it is only polite to give thanks when you are served. After a person's cup is filled, that person may knock his bent index and middle fingers (or some similar variety of finger tapping) on the table to express gratitude to the person who served the tea.This custom originated in the Qing Dynasty, about 300-400 years ago. At that time, Emperor Qian Long would sometimes travel incognito through the empire to experience first hand the way of life of his citizens. Servants were told not to reveal their master's identity. One day in a restaurant, the emperor, after pouring himself a cup of tea, filled a servant's cup as well. To that servant it was a huge honour to have the emperor pour him a cup of tea. Out of reflex he wanted to kneel and express his thanks. He could not kneel and kowtow to the emperor since that would reveal the emperor's identity so he bent his fingers on the table to express his gratitude and respect to the emperor. This "thanks" knock is still in use today in China and Chinese-influenced areas.