A Yale lecturer who came under attack for challenging students to stand up for their right to decide what Halloween costumes to wear, even to the point of being offensive, has resigned from teaching at the college, the university said Monday.

The lecturer, Erika Christakis, an expert in early childhood education, wrote an email in October suggesting that there could be negative consequences to students ceding “implied control” over Halloween costumes to institutional forces. “I wonder, and I am not trying to be provocative: Is there no room anymore for a child or young person to be a little bit obnoxious,” she wrote, “a little bit inappropriate or provocative or, yes, offensive?”

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.