Nearly 20 percent of Israeli Facebook users cut off “friends” during the Gaza war, with people on the political extremes most likely to do so, a new study shows.

The study, led by Prof. Nicholas John, a sociologist at the Hebrew University of Jerusalem, found that one in six Israeli Jewish Facebook users “unfriended” or “unfollowed” people during Operation Protective Edge. Half of those people made four or more cuts.

On the social network, unfriending and unfollowing both involve restricting the sharing of information. Only unfriending affects the other person and is detectable by him or her.

The further people were from the political center, the more likely they were to unfriend someone — and the direction was unimportant, the study found. People on the left were just as likely to unfriend someone as were those on the right. Being more politically engaged was also a predictor. Reasons for unfriending someone included being offended by, or simply disagreeing with, their posts.

“It shows that unfriending on Facebook is quite a new phenomenon through which people create homogeneous media environments or ‘echo chambers,’ filtering out content that either offends them, that they disagree with, or that they don’t want to be associated with,” said Prof. John.

Ten days after the ceasefire between Israel and Hamas, John surveyed 1,013 Jewish Israeli Facebook users for the study. He found that Israelis were more political on Facebook during the war than they were in the 12 months beforehand. While nearly half of the people in the study said they did not post content related to the war, 6.4 percent said they posted such content “a great deal.”

Among the survey respondents, 60 percent identified as right-wing, 20 percent as in the center, and 20 percent as left-wing — consistent with Israel Democracy Institute figures. Younger users were significantly more likely to unfriend someone than were older users. The difference, John says, may be that young people identify more with their Facebook profiles.

The results provide a profile of the typical Israeli Jewish “unfriender” during the war: A young person who was politically engaged and had strong political views. This person was most likely to unfriend people he disagreed with and with whom he had weak personal ties.

Notably, the study found that people in the south of Israel, who endured most of the rocket fire from the Gaza Strip during the war, were no more likely than other Israeli Jews to unfriend or unfollow people.

One-quarter of those surveyed considered unfriending or unfollowing someone, but ultimately chose not to. Only 3.4 percent of respondents thought they had been unfriended, and of those people, 70 percent did not care.