Caste is often thought of as an ancient fact of Hindu life, but various contemporary scholars argue that the caste system was constructed by the British colonial regime.[8] Between 1860 and 1920, the British segregated Indians by caste, granting administrative jobs and senior appointments mostly to educated people. Social unrest during 1920s led to a change in this policy.[9][10] From then on, the colonial administration began a policy of positive discrimination by reserving a certain percentage of government jobs for the lower castes.[11] After India achieved independence, this policy of caste-based reservation of jobs was formalised with lists of Scheduled Castes and Scheduled Tribes.[12]