Why did Chinese opera performers traditionally train for seven years as children?

In traditional Chinese opera, performers undergo seven years of training as children primarily to master the highly conventionalized skills required for the stage and to determine their appropriate role type.1

During this intensive period, students are evaluated to see which specific character category they are best suited to portray: the male (sheng), female (dan), painted-face warrior (jing), or clown (chou). Because Chinese opera relies on a complex system of symbolism, singing, and pantomime—such as manipulating long "flowing water" sleeves or executing precise acrobatic movements—this long apprenticeship is essential for performers to internalize the rigorous techniques necessary for their roles.1