Fewer than half of American adults know how many Jews were killed in the Holocaust, according to a survey published ahead of International Holocaust Remembrance Day on January 27.

Forty-five per cent of those asked by the Pew Research Center about the number of Jews killed by the Nazis gave the correct answer of approximately 6 million.

From multiple choice answers, 12% selected about 3 million, and 2% selected less than 1 million. Another 12% said more than 12 million Jews died in the Holocaust. One in three people (29%) said they were not sure or did not answer.

According to the survey of almost 11,000 Americans, 69% said the Holocaust happened between 1930 and 1950. One in 10 people thought it took place between 1910 and 1930, and 2% answered between 1890 and 1910. One in 100 people thought it was later than second world war, answering 1950-1970; and 18% did not know or gave no answer.

Some people believe ignorance about the Holocaust is linked to a rise in antisemitism. There are also concerns that, as living witnesses to Nazi atrocities and the death camps dwindle in number, the Holocaust is receding in the collective memory.

The Anti-Defamation League annual audit of antisemitic incidents in the US for 2018 recorded the third-highest total since the civil rights group began publishing data 40 years ago.

According to the New York Times, a report soon to be published by the Center for the Study of Hate and Extremism at California State University says antisemitic hate crimes in New York, Los Angeles and Chicago – the three largest cities in the US – are poised to hit an 18-year peak.

Last month, a man armed with a knife forced his way into the home of a New York rabbi during the Jewish holiday of Hanukkah, wounding five people. In October 2018, 11 people were killed and six injured in a shooting attack at a synagogue in Pittsburgh, Pennsylvania.

The Pew survey also found that only 43% of respondents knew that Hitler became German chancellor through a democratic political process, with one in four people believing he and his supporters violently overthrew the government.

The Pew report, What Americans Know About the Holocaust, said the findings raised an important question: “Are those who underestimate the death toll simply uninformed, or are they Holocaust deniers – people with antisemitic views who ‘claim that the Holocaust was invented or exaggerated by Jews as part of a plot to advance Jewish interests’?”

The researchers found some correlation between correct answers and warmer feelings among non-Jews towards Jews. Those answering at least three of the four multiple-choice questions correctly had, on average, a 67% “warmth rating” towards Jews.

January 27 marks the 75th anniversary of the liberation of Auschwitz, the death camp in German-occupied Poland where some 1.2 million people were killed. Up to 200 survivors are expected to attend a memorial service at the camp, and there will be commemorations around the world.