3.7 Diffusion of Religion and Language

A language family is a group of languages descended from one ancient ancestor. A branch is a large subgroup within a family, like the Romance or Germanic branch. A language is a specific system of communication, like Spanish. A dialect is a regional or social variety of a language, with its own accent, words or grammar, like the Southern American English use of “y'all.”

Indo-European is the language family with the most native speakers, close to half of the world's population (Ethnologue). It includes the Romance branch (Spanish, Portuguese, French, Italian, from Latin), Germanic (English, German, Dutch), Slavic (Russian, Polish) and Indo-Iranian (Hindi, Bengali, Persian). Other major families include Sino-Tibetan (Mandarin), Afro-Asiatic (Arabic, Hebrew), Niger-Congo (Swahili, Zulu, Yoruba), Austronesian (Indonesian, Tagalog, Malagasy, Hawaiian) and Dravidian (Tamil, Telugu).

Scholars debate the hearth. The Anatolian hypothesis says Indo-European languages spread from present-day Turkey with farming, roughly 8,000 to 9,000 years ago. The steppe (Kurgan) hypothesis says they spread from the grasslands north of the Black and Caspian Seas with horse-riding herders, roughly 5,000 to 6,000 years ago. Ancient DNA studies since 2015 have given strong support to the steppe hypothesis, but the debate isn't fully closed.

Later diffusion is clearer: Latin spread through the Roman Empire and became the Romance languages, and colonialism carried English, Spanish, French and Portuguese worldwide. Austronesian shows how far relocation can go: seafarers carried it from Taiwan across the Pacific and Indian Oceans as far as Madagascar and Hawaii.

Toponyms are place names, and they record who lived somewhere and when. Spanish names across the U.S. Southwest (Los Angeles, Santa Fe, the Sierra Nevada) mark former Spanish and Mexican rule. Many U.S. state names, like Mississippi and Massachusetts, come from Native American languages. Names change when power shifts: Bombay became Mumbai in 1995, and Saigon was renamed Ho Chi Minh City in 1976.

Universalizing religions seek converts and welcome anyone. They spread by expansion diffusion (missionaries, conversion of rulers, trade contacts) and by relocation diffusion (believers moving). Ethnic religions are closely tied to a particular people and place, rarely seek converts, and are mostly found near their hearth or spread when their followers migrate. Pew Research estimated that in 2020 there were about 2.3 billion Christians, 2.0 billion Muslims, 1.2 billion Hindus, 320 million Buddhists and 15 million Jews.

Major religions have branches with their own regional patterns. Christianity's main branches are Catholic (dominant in Latin America and southern Europe), Protestant (northern Europe, the U.S.) and Eastern Orthodox (Russia, Greece, Eastern Europe). Islam's are Sunni, the large majority, and Shia, the majority in Iran and Iraq. Buddhism's main branches are Theravada in Sri Lanka, Myanmar, Thailand, Laos and Cambodia; Mahayana in China, Korea, Japan and Vietnam; and Vajrayana in Tibet, Bhutan and Mongolia. Buddhism is now a small minority in India, where it began.