Research has several answers as to what caused the distinct syncretic (its modern expression is cultural Islam, as opposed to Middle Eastern and North African political Islam) Islam in Southeast Asia, that allowed the continuation and inclusion of elements and ritual practices of Hinduism, Buddhism and ancient Pan-East Asian Animism. Most principalities had developed highly distinctive cultures as a result of centuries of active participation in the cultural interchange and by borrowing from the flow of ideas that criss-crossed the archipelago, coming from across the Indian Ocean in the west and the South China Sea in the east. Cultural and institutional adoption was a creative and selective process, in which foreign elements were incorporated into a local synthesis.