Papua New Guinea is home to nearly 1,000 distinct languages—about 12% of all languages on Earth—and has the world’s highest linguistic diversity. Its population is uncertain, estimated between 10 and 17 million. The island saw bow and arrow battles as late as 1963, and urban arrow violence persists.

Cannibalism was practiced, including by groups that consumed relatives’ brains, leading to kuru—a prion disease that drove a rapid genetic mutation for resistance, one of the fastest examples of natural selection in humans. Jared Diamond has suggested highlanders may be genetically smarter than Europeans. Until 1930, the highlands were unknown to outsiders; Australians believed no one lived there.

After gold was found in 1926, Mick Leahy ventured inland and discovered a million people in lush, malaria-free valleys. His 1930 encounter, documented with photos and film, revealed a society untouched by the outside world. The book First Contact: New Guinea’s Highlanders Encounter the Outside World details this moment, including Leahy’s decade of exploration and 1970s interviews with those who witnessed first contact.

The coastal regions are malaria-infested swamps and jungles, while the highlands, despite being near the equator, have glaciers and peaks under 5,000 metres. New Guinea remains a place of profound cultural and biological significance, largely misunderstood by the world.