Hersh sought to gauge how pervasive the concerns of Jewish students are — and how their classmates feel about them.

“It’s hard to know from the anecdotes on social media or in the press,” Hersh said, “whether the narrative of campuses having widespread antisemitism or feelings of [widespread antisemitism]” are true. The survey data revealed that “the feelings of social penalties . . . are just obviously fairly widespread.”

The survey, conducted in November and December last year, also asked non-Jewish students about their Jewish peers. Their answers seemed, according to Hersh, to provide some empirical evidence for Jewish students’ concerns. One question asked non-Jewish students if they would be friends with someone who supports Israel’s existence. Eighteen percent of the total said they wouldn’t, and 39 percent weren’t sure.

A small minority — 6 percent of the non-Jewish respondents — said they avoid socializing with Jews altogether “due to their views on Israel.”

The anonymous survey was completed by about 1,000 Jewish students and about 1,500 non-Jewish students at 21 American colleges and universities with large Jewish populations. It was administered by College Pulse, a research group that has also conducted surveys of college students with the Wall Street Journal and the Foundation for Individual Rights and Expression. The project was funded by the Jim Joseph Foundation, a charity focused on Jewish education.

Hersh released his survey results last week just as new antisemitic campus incidents and a clash between pro- and anti-Israel students came to light. At Smith College in Northampton, graffiti swastikas were discovered on crosswalks near campus, according to a March 1 email sent by Smith leaders including president Sarah Willie-LeBreton. The campus police are also investigating two reports of stolen mezuzahs, religious objects some observant Jews affix to door frames, a Smith spokesperson said.

Tufts University leaders also sent a campuswide message last week about “reports of some extremely disturbing antisemitic words and conduct” and “Islamophobic actions” at a student government meeting where anti-Israel resolutions were approved. After the meeting, pro-Palestinian and Jewish students both alleged they were spit on and targeted with bigoted statements and taunts.

The recent events follow months of campus turmoil. Jewish students have alleged that activism against Israel’s war in the Gaza Strip has sometimes included antisemitic speech and conduct. Pro-Palestinian students have said they have been unfairly accused of bigotry for their righteous opposition to Israel’s war, which has killed at least 30,000 people. They also allege that their critics, including university administrators, donors, and lawmakers, have used allegations of antisemitism to silence their political speech.

The tumult has taken a toll. In Hersh’s survey, 42 percent of Jewish students, as well as 38 percent of Muslim students, said their mental health has deteriorated since the war began.

Many of the campus disputes boil down to fierce disagreements about where the line is between antisemitism — that is, bigotry against Jews — and anti-Zionism, a belief that Israel should not exist as a Jewish state in the Holy Land.

In Hersh’s survey, 69 percent of Jewish students agreed with the Zionist position: that there should “continue to be a Jewish state in Israel/Palestine.” Seventeen percent said there should not continue to be a Jewish state; 15 percent answered “I don’t know.”

When non-Jewish students were asked if they would want to be friends with supporters of Israel’s existence, their answers varied significantly by political ideology.

More than one-third of self-described socialists said they would not want to be friends with an Israel supporter, compared with one in 10 libertarians.

Jewish students who spoke with The Boston Globe last week — none of them participants in the survey — said Hersh’s finding that left-leaning students were less likely to befriend Israel supporters was consistent with their experience. They also broadly agreed with the survey’s finding that at least some Jewish students pay a price for their real or perceived support for Israel.

Maya Rackoff, a student at Brown University, said Jews who do not support Israel do not face social penalties. “If you’re Jewish on campus and you’re anti-Zionist, you’re totally fine,” she said. “No one has an issue with you.”

Maya Cohen, a student at Simmons University in Boston, said she tries to hide signs of her Jewish identity on campus. When she wears necklaces with a Star of David or Hebrew letters, she said, she flips them over or hides them under a sweater as she walks through campus.

Shira Hoffer, a student at Harvard, said it doesn’t occur to her to hide her Jewish identity. “I have never felt like being outwardly Jewish has given me fewer social, academic, or professional opportunities,” she said. She added, however: “Insofar as people often conflate Judaism and Zionism, people who are anti-Zionist may judge Jews negatively based on that conflation.”

Hersh found that amid the post-Oct. 7 campus turmoil, Jewish students, including those with weaker ties to Jewish religion and culture, have drawn closer to the Jewish community.

When his earlier survey asked Jewish students in April 2022 how close they felt to a Jewish community, 17 percent answered “very close.” By November and December of last year, when he asked the same question again, that percentage had more than doubled to 35 percent.

“We’ve seen a lot of students coming out of the woodwork trying to seek community and support,” said Cohen.

Mike Damiano can be reached at mike.damiano.com.