She wrote the email in response to a directive from the Intercultural Affairs Committee at Yale that warned students that it would be insensitive to wear costumes that symbolized cultural appropriation or misrepresentation, or both, like feathered headdresses, turbans, war paint, blackface or redface, or costumes that made fun of people.

Ms. Christakis has made a “voluntary decision not to teach in the future,” according to a statement from the university on Monday. Her husband, Dr. Nicholas Christakis, a physician and a professor of sociology at Yale, will take a one-semester sabbatical, the university said. The statement said the administration hoped Ms. Christakis would reconsider…

After the email, a group of students confronted Dr. Christakis. One student was shown in a video posted on YouTube confronting Dr. Christakis as he clasped his hands. “It is not about creating an intellectual space! It is not!” the student was heard yelling. “Do you understand that? It is about creating a home here!”