Ruby Rodriguez, 8, crosses the Rio San Lorenzo de Morovis with her family after the bridge that crossed the river was swept away by Hurricane Maria, in Morovis, Puerto Rico. They were returning to their home after visiting family on the other side. (Gerald Herbert/AP)

It’s no great secret that Americans overall know very little about the history — and even current state — of their own country, as poll after test after survey after embarrassing statement have proved for decades.

The just-released 2017 civics survey conducted by the Annenberg Public Policy Center at the University of Pennsylvania found, among other things:

  • More than a third of American adults (37 percent) can’t name any of the rights guaranteed under the First Amendment.
  • Only a quarter of American adults (26 percent) can name all three branches of government.
  • More than half of American adults (53 percent) incorrectly think it is accurate to say that immigrants who are here illegally do not have any rights under the U.S. Constitution.

Last year’s survey by the Annenberg center found:

  • Nearly 4 in 10 (39 percent) incorrectly said the Constitution gives the president the power to declare war. Just more than half (54 percent) knew the Constitution gives Congress the power to declare war.
  • A vast majority (83 percent) correctly said the Constitution gives Congress the power to raise taxes.
  • A majority (77 percent) know the Constitution says that Congress cannot establish an official religion — though almost 1 in 10 agreed with the statement that the Constitution says, “Congress can outlaw atheism because the United States is one country under God.”

A 2015 U.S. Government Accountability Office report, using nationally representative Education Department data, found that about 75 percent of eighth-graders across the country did not have a solid grasp of geography, and the report concluded that a majority of states do not require geography courses in middle school or high school.

If test scores are your favored assessment measure, look at the 2014 results in history, geography and civics on the National Assessment of Educational Progress, sometimes referred to as “the nation’s report card.” Only 18 percent of eighth-graders scored proficient in U.S. history, 27 percent were at or above proficient in geography and 23 percent performed at or above proficient in civics — though it is important to note that NAEP proficiency levels are considered higher than grade-level proficiencies.

Go back a decade or so: A 2006 National Geographic-Roper poll on young Americans’ knowledge of geographic literacy found that half of 18- to 24-year-olds couldn’t point out the state of New York on a map.

Now, we have a new example of American historical and civic illiteracy. This one involves Puerto Rico, the island recently devastated by two hurricanes.

Puerto Rico is not a foreign country, at least it isn’t if you live in the United States. It is a U.S. territory, and those on the island who were born in Puerto Rico are American citizens (though, like denizens of the District of Columbia, have no voting rights in Congress).

But a new poll by an outfit called Morning Consult, as reported in the New York Times, found that only 54 percent of Americans know that people born in Puerto Rico are American citizens. The story said:

This finding varied significantly by age and education. Only 37 percent of people ages 18 to 29 know people born in Puerto Rico are citizens, compared with 64 percent of those 65 or older. Similarly, 47 percent of Americans without a college degree know Puerto Ricans are Americans, compared with 72 percent of those with a bachelor’s degree and 66 percent of those with a postgraduate education.

A May 2016 Economist/YouGov poll had even worse results: Only 43 percent of those who replied knew that Puerto Ricans were U.S. citizens.

The Puerto Rico Report reported that last year, Stephen Moore, a senior economic contributor at FreedomWorks and a distinguished visiting fellow with the Project for Economic Growth at the right-wing Heritage Foundation, said this while testifying before the Senate Judiciary Committee:

“Look at what’s happened in Greece. You know, look at what Greece has to — the rates of interest they have to — they have to pay to borrow. You know, they’re in the double digits. And another country, look at Puerto Rico for goodness sakes. I mean, they’ve racked up so much debt that that country is coming running to Washington to get a bailout.”

Such attitudes, some say, may help explain why there has been less urgency in the United States to help the hurricane-ravaged island compared with the response when Texas and Florida got hit recently by hurricanes.

And such attitudes provide yet more evidence, as if any were needed, that Americans’ lack of understanding of their own country can have important consequences for people beyond simply being thought of as dumb.