Story highlights In the survey, 62% of adults knew the decision affirmed a woman's right to abortion

Only 44% of those polled under the age of 30 could say the case dealt with abortion

One in five said they had no idea what the case dealt with, report says

Tuesday is the 40th anniversary of the U.S. Supreme Court's landmark Roe v. Wade decision, but a poll shows that many Americans don't know the significance of the case.

According to a new study released by Pew Research Center, only 62% of adults polled knew the decision affirmed the legality of a woman's right to abortion under the 14th Amendment to the Constitution, and only 44% of those polled under the age of 30 could say the case dealt with abortion.

Among the under-30 set, Pew says, 16% thought the case dealt with school desegregation, and 41% either said it dealt with another issue or had no idea what it dealt with.

In comparison, 7% of all adults polled incorrectly associated the decision with school desegregation, 5% associated it with the death penalty, and 5% more thought the ruling dealt with environmental protection, according to a Pew report.

One in five said they had no idea what the case dealt with.

Equal percentages of women and men were aware that the case decided abortion rights, at 62% each, the report said.

Political parties differed, however, with 68% of Republicans, 63% of independents and 57% of Democrats able to identify the historic court case, Pew said.

The telephone poll was taken January 9-13 among 1,502 adults, ages 18 and older. The results were released on January 16. The poll's margin of error was plus or minus 2.9 percentage points.