Erika Christakis. Yale College Erika Christakis, the faculty member at the center of a racially charged debate at Yale, has decided not to teach at the Ivy League school going forward.

"I will not be teaching at Yale in the future," she told Business Insider in an email Thursday.

Christakis' decision came after weeks of backlash against the lecturer and administrator over an email she sent to students suggesting that Yale shouldn't tell them not to wear offensive Halloween costumes.

That backlash included an open letter criticizing her signed by hundreds of members of the Yale community.

Recently, 49 faculty members wrote their own open letter defending Christakis against allegations of racism.

Douglas Stone, a colleague who wrote the open letter, told Business Insider that "aggressive tactics" used against Christakis spurred her to decide to stop teaching.

"Last year over 300 students expressed interest in her courses, she is an acclaimed teacher, and she was planning extra sections this year to accommodate more students," Stone wrote Business Insider in an email message. "The unfair and ad hominem attacks she has endured have measurably reduced student academic choice at Yale. There is a cost to allowing this behavior to go unchallenged."

Yale physics professor Douglas Stone. screengrab via youtube Christakis — an associate master at Yale's Silliman College who also teaches child-development and education classes — sent the now notorious email in response to an Intercultural Affairs Council email that called on students to be sensitive about the cultural implications of their Halloween costumes, as Inside Higher Ed reported. Silliman College is one of 12 residential colleges, also known as dormitories, at Yale.

Christakis questioned if students should be able to dress in any costumes they liked, offensive or not.

“Is there no room anymore for a child or young person to be a little bit obnoxious … a little bit inappropriate or provocative or, yes, offensive?” she wrote. (See below for the full email).

Stone said that as tension on campus rose, he felt an obligation to step in and show support for Christakis.

"I do not want to stir up angry debate, but felt that the debate up to this point has been one-sided and needed to be balanced," he said.

Yale students protesting racial discrimination on campus. Philipp Arndt Photography When asked if he thought Yale was a welcoming place for students of color, Stone indicated he didn't feel close enough to the issue to opine, but that he hasn't seen institutional racism at Yale.

"I do not have enough involvement with these issues and personal knowledge to make a judgment," he said.

"I can say that as a long time department Chair we were very vigorously encouraged to recruit under-represented minorities and be sensitive to their needs. I never saw evidence of the institutional racism that some have charged is present."

The Christakises received support from Yale's administration in November, after nearly a month of escalating tension. President Peter Salovey and Yale College Dean Jonathan Holloway sent an email to students affirming that they "fully support" the Christakises, YDN reported.

But Stone was disappointed with the platitudes, rather than direct support, that Salovey and Holloway used in their email.

"I was disappointed that the President Salovey and Dean Holloway did not defend Erika's email explicitly, but restricted themselves to general expressions of support for free speech," he said.

"I think Erika's email was a useful and important contribution to campus discourse."

Business Insider reached out to Yale University for comment and will update this post if we hear back. Read below for the full text of Erika Christakis' email.

Dear Sillimanders:

Nicholas and I have heard from a number of students who were frustrated by the mass email sent to the student body about appropriate Halloween-wear. I’ve always found Halloween an interesting embodiment of more general adult worries about young people. As some of you may be aware, I teach a class on “The Concept of the Problem Child,” and I was speaking with some of my students yesterday about the ways in which Halloween – traditionally a day of subversion for children and young people – is also an occasion for adults to exert their control.

When I was young, adults were freaked out by the specter of Halloween candy poisoned by lunatics, or spiked with razor blades (despite the absence of a single recorded case of such an event). Now, we’ve grown to fear the sugary candy itself. And this year, we seem afraid that college students are unable to decide how to dress themselves on Halloween.

I don’t wish to trivialize genuine concerns about cultural and personal representation, and other challenges to our lived experience in a plural community. I know that many decent people have proposed guidelines on Halloween costumes from a spirit of avoiding hurt and offense. I laud those goals, in theory, as most of us do. But in practice, I wonder if we should reflect more transparently, as a community, on the consequences of an institutional (which is to say: bureaucratic and administrative) exercise of implied control over college students.

It seems to me that we can have this discussion of costumes on many levels: we can talk about complex issues of identify, free speech, cultural appropriation, and virtue “signaling.” But I wanted to share my thoughts with you from a totally different angle, as an educator concerned with the developmental stages of childhood and young adulthood.

As a former preschool teacher, for example, it is hard for me to give credence to a claim that there is something objectionably “appropriative” about a blonde-haired child’s wanting to be Mulan for a day. Pretend play is the foundation of most cognitive tasks, and it seems to me that we want to be in the business of encouraging the exercise of imagination, not constraining it. I suppose we could agree that there is a difference between fantasizing about an individual character vs. appropriating a culture, wholesale, the latter of which could be seen as (tacky)(offensive)(jejeune)(hurtful), take your pick. But, then, I wonder what is the statute of limitations on dreaming of dressing as Tiana the Frog Princess if you aren’t a black girl from New Orleans? Is it okay if you are eight, but not 18? I don’t know the answer to these questions; they seem unanswerable. Or at the least, they put us on slippery terrain that I, for one, prefer not to cross.

Which is my point. I don’t, actually, trust myself to foist my Halloweenish standards and motives on others. I can’t defend them anymore than you could defend yours. Why do we dress up on Halloween, anyway? Should we start explaining that too? I’ve always been a good mimic and I enjoy accents. I love to travel, too, and have been to every continent but Antarctica. When I lived in Bangladesh, I bought a sari because it was beautiful, even though I looked stupid in it and never wore it once. Am I fetishizing and appropriating others’ cultural experiences? Probably. But I really, really like them too.

Even if we could agree on how to avoid offense – and I’ll note that no one around campus seems overly concerned about the offense taken by religiously conservative folks to skin-revealing costumes – 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… a little bit inappropriate or provocative or, yes, offensive? American universities were once a safe space not only for maturation but also for a certain regressive, or even transgressive, experience; increasingly, it seems, they have become places of censure and prohibition. And the censure and prohibition come from above, not from yourselves! Are we all okay with this transfer of power? Have we lost faith in young people’s capacity – in your capacity – to exercise self-censure, through social norming, and also in your capacity to ignore or reject things that trouble you? We tend to view this shift from individual to institutional agency as a trade off between libertarian vs. liberal values (“liberal” in the American, not European sense of the word).

Nicholas says, if you don’t like a costume someone is wearing, look away, or tell them you are offended. Talk to each other. Free speech and the ability to tolerate offense are the hallmarks of a free and open society.

But – again, speaking as a child development specialist – I think there might be something missing in our discourse about the exercise of free speech (including how we dress ourselves) on campus, and it is this: What does this debate about Halloween costumes say about our view of young adults, of their strength and judgment?

In other words: Whose business is it to control the forms of costumes of young people? It’s not mine, I know that.

Happy Halloween.

Yours sincerely,

Erika