According to this act indigenous groups became historically differentiated from majority of Filipinos ?

The act that led to the historical differentiation of indigenous groups from the majority of Filipinos is the Indigenous Peoples Rights Act (IPRA) of 1997. This law recognizes and protects the rights of indigenous peoples in the Philippines, including their right to self-determination, ancestral domain, cultural integrity, and social justice. It acknowledges the distinct cultural, social, economic, and political identities of indigenous groups, which sets them apart from the majority of Filipinos.