Step 1: Understand the context of Gaddi tribe inclusion.
The Gaddi community is a tribal community primarily residing in the Bharmaur and Holi tehsils of Chamba district, Himachal Pradesh. They have traditionally practiced transhumance (seasonal migration with livestock) and speak the Gaddiali dialect [citation:6].
Step 2: Identify the decade of inclusion.
According to multiple sources, the Gaddis were included in the Scheduled Tribe list in the
1970s [citation:6][citation:9]:
- The process of development of the tribal area of Bharmaur started in the 1970s when Gaddis were included among 'scheduled tribes' [citation:6].
- Bharmaur was notified as a tribal area on 21 November 1975 [citation:6][citation:9].
- Under the Fifth Five-Year Plan, the Tribal Sub-Plan was introduced in 1974 and Bharmaur was designated as one of the five Integrated Tribal Development Projects (ITDP) in Himachal Pradesh [citation:6].
Step 3: Verify with other sources.
Earlier, only the Gaddis from Chamba district were notified as Scheduled Tribes. Later, in 2002-2003, all Gaddis from different areas of Himachal Pradesh were re-notified as Scheduled Tribes [citation:4]. However, the initial inclusion specifically for Chamba district occurred in the 1970s.
Step 4: Analysis of each option.
- (A) 1950s: Incorrect. While the Scheduled Tribe category was established by Constitutional Order in 1950 [citation:2][citation:10], the Gaddis were not initially included in this decade.
- (B) 1960s: Incorrect. No evidence suggests inclusion during this decade.
- (C) 1970s: Correct.} Multiple sources confirm the Gaddis were included in the Scheduled Tribe list in the 1970s, with formal notification in 1975.
- (D) 1980s: Incorrect. The Modified Area Development Approach (MADA) was adopted for Chamba and Bhatiyat blocks in 1981-82 [citation:7], but the initial ST inclusion happened earlier.
Final Answer:} (C) 1970s