Indigenous Philippine folk religions are the distinct native religions of various ethnic groups in the Philippines, where most follow belief systems in line with animism. Generally, these indigenous folk religions are referred to as Anito or Anitism or the more modern and less ethnocentric Dayawism. Around 0.2% of the population of the Philippines were affiliated with the so-called "tribal religions", according to the 2010 national census. The profusion of different terms arises from the fact that these indigenous religions mostly flourished in the pre-colonial period before the Philippines had become a single nation. The various peoples of the Philippines spoke different languages and thus used different terms to describe their religious beliefs. While these beliefs can be treated as separate religions, scholars have noted that they follow a "common structural framework of ideas" which can be studied together. The various indigenous Philippine religious beliefs are related to the various religions of Oceania and the maritime Southeast Asia, which draw their roots from Austronesian beliefs as those in the Philippines. The folklore narratives associated with these religious beliefs constitute what is now called Philippine mythology, and is an important aspect of the study of Philippine culture and Filipino psychology. Religious worldview Historian T. Valentino Sitoy, in his review of documents concerning pre-Spanish religious beliefs, notes three core characteristics which shaped the religious worldview of Filipinos throughout the archipelago before the arrival of Spanish colonizers. First, Filipinos believed in the existence of parallel spirit world, which was invisible but had an influence on the visible world. Second, Filipinos believed that there were spirits (anito) everywhere - ranging from the high creator gods to minor spirits that lived in the environment such as trees or rocks or creeks. Third, Filipinos believed that events in the human world were influenced by the actions and interventions of these spirit beings. Anito were the ancestor spirits (umalagad), or nature spirits and deities (diwata) in the indigenous animistic religions of precolonial Philippines. Pag-anito (also mag-anito or anitohan) refers to a séance, often accompanied by other rituals or celebrations, in which a shaman (Visayan: babaylan, Tagalog: katalonan) acts as a medium to communicate directly with the spirits. When a nature spirit or deity is specifically involved, the ritual is called pagdiwata (also magdiwata or diwatahan). Anito can also refer to the act of worship or a religious sacrifice to a spirit. When Spanish missionaries arrived in the Philippines,