Every episode,
in one place.

S4 · E3 · Nov 4, 2026

In Recife, Brazil, in the early 1980s, researchers posed as customers and bought coconuts, popcorn, and lemons from five children who worked the street markets. The children got 98 percent of the arithmetic right. A week later, on paper, with the same numbers, they got most of it wrong. This episode follows that finding: what the children knew, why the written test could not count it, and the Brazilian mathematician who named the problem ethnomathematics the same year. Then it follows the method of looking to places where adults went to find what children already knew: teachers in Tucson visiting their own students' homes and coming back with funds of knowledge; a second adult beside the teacher in the far south of Thailand who speaks Patani Malay; community teachers hired from the villages in Cambodia's highlands and moved onto the state payroll. The rule underneath: the question is never whether the knowledge is there. The question is whether the teacher in the classroom can recognize it. The episode closes with the season's recurring question, would it take root?

S4 · E2 · Oct 28, 2026

In a village primary school in rural India, researchers compared a child with herself: one subject taught by a teacher who shared her gender, caste, and religion, another by a teacher who did not. She scored higher in the matched subject. That is ethnic matching, measured in a country where the markers are not race. This episode asks what counts as the match once the boxes on the form change: what a match has meant in the United States and why that is one country's definition; a new U.S. study finding the largest gains when a teacher shares both a student's ethnicity and language; Japan's Ainu, recognized in 2008 and 2019, and why a match cannot be studied or staffed for until the state admits a people exists. The rule underneath all of it: whoever designs the form decides what a match is. The episode closes with the season's recurring question, would it take root?

S4 · E1 · Oct 21, 2026

In January 1970, the University of Ife in Nigeria began teaching a group of primary children in Yoruba for all six years of school, with English as a subject. In 2022, Nigeria made home-language instruction national policy for the early grades. In November 2025, the next government cancelled it and restored English, citing exam results. The Nigerian Academy of Education said the evidence showed the opposite. This episode follows that decision around the world. UNESCO estimates that about forty percent of the world's people are not taught in a language they understand well. Ethiopia, Tanzania, and Kenya answered the question three different ways. Brazil, Morocco, Catalonia, the Basque Country, and Aotearoa New Zealand wrote a people, or a language, into the lesson, and found that a law takes a year and teachers take a generation. In the United States the question was answered in court, in Lau v. Nichols, 1974, unanimously. The episode closes with the season's recurring question: would it take root?

S4 · E0 · Oct 14, 2026

Season 4 of The Cultural Context of Knowledge follows one question around the world: who teaches whom, in whose language, and who decided. Eight episodes, with the United States in every one of them as one case among many. The trailer opens in four classrooms at eight in the morning, on the coast of Kenya, in central India, in Barcelona, and in San Francisco in 1970. In each, the language of the lesson is not the language of the children's homes. UNESCO estimates that about forty percent of the world's people are not taught in a language they understand well. The trailer also explains why the research season promised at the end of Season 3 is now Season 5, and closes with three questions to try before Episode 1.