The rigid nature of caste systems often leads to limited social mobility. What is the underlying cause of this rigidity compared to class systems?

Caste systems are rigid because they are based on birth, meaning people are assigned a social status that they cannot change throughout their lives. This is different from class systems, which allow individuals to move up or down based on factors like education, income, and personal achievements. In a caste system, if you are born into a lower caste, you often face discrimination and limited opportunities, making it hard to improve your social position. For example, a person born into a family of manual laborers might find it very difficult to become a doctor, no matter how hard they study or work. In contrast, someone in a class system could start with little money but, through education and hard work, could eventually become wealthy and respected.