Nearly two-thirds of Americans think it is possible that some federal officials had specific warnings of the Sept. 11, 2001, terrorist attacks on New York and Washington, but chose to ignore those warnings, according to a Scripps Howard News Service/Ohio University poll.

A national survey of 811 adult residents of the United States conducted by Scripps and Ohio University found that more than a third believe in a broad smorgasbord of conspiracy theories including the attacks, international plots to rig oil prices, the plot to assassinate President John F. Kennedy in 1963 and the government’s knowledge of intelligent life from other worlds.

The high percentage is a manifestation, some say, of an American public that increasingly distrusts the federal government.

‘‘You wouldn’t have gotten these numbers a year or two after the attacks themselves,’’ said University of Florida law professor Mark Fenster. ‘‘You’ve got an increasingly disaffected public that is unhappy with the administration.’’

Fenster, author of the book ‘‘Conspiracy Theories: Secrecy and Power in American Culture,’’ attributed the high percentage in part to the findings of the National Commission on Terrorist Attacks upon the United States (also called the 9/11 Commission), which concluded federal officials failed to prevent the attacks, but did not have specific knowledge of the date of the attacks.

An earlier Scripps Howard/Ohio University survey, conducted in July 2006, revealed that more than one-third of Americans thought federal officials assisted in the 9/11 attacks or took no action to stop them so the United States could go to war in the Middle East.

‘‘What (the recent survey) could mean is that people are thinking that the Bush administration is incompetent, that there were warnings out there and they chose to put their attention on other things,’’ Fenster said.

At a time when the price of crude oil has neared $100 per barrel, 81 percent of Americans also said it was ‘‘somewhat likely’’ or ‘‘very likely’’ that oil companies conspire to keep the price of gasoline high.

‘‘It shows that the oil companies are not trusted by a lot of people,’’ said Tyson Slocum, director of the Energy Program of Public Citizen, the consumer watchdog organization founded by Ralph Nader.

Record-breaking quarterly profits stir the pot, too.

‘‘People look at the huge profits and put two and two together,’’ he said. ‘‘’Those high prices I’m paying are fueling those profits.’’’

All the talk about oil and terror has distracted some of the believers in government cover-ups of UFOs. Thirty-seven percent of the respondents said they think it is ‘‘very likely’’ or ‘‘somewhat likely’’ flying saucers are real and the government is hiding the truth about them. In a 1995 Scripps survey, 50 percent of Americans responded the same way to the same question.

‘‘The kind of anxieties or mistrust of the government that might have been expressed as a belief in UFOs has shifted,’’ said political science professor Jodi Dean. ‘‘Now people are worried about things that are much realer to them.’’

‘‘In both instances, it’s a case of mistrusting government,’’ she said.

Dean, a professor at Hobart and William Smith Colleges in New York and author of ‘‘Aliens in America: Conspiracy Cultures from Outerspace to Cyberspace,’’ also said that the 50th anniversary of the 1947 Roswell, N.M., incident put more focus on the notion of a conspiracy.

Dean said she expects the popularity of the theory to decline even further during the next few decades.

But one decades-old theory continues to thrive. Forty-two percent of the American public still thinks some people in the federal government might have known about the assassination of Kennedy in advance.

‘‘I’m amazed that it’s as high as it is,’’ said Vincent Bugliosi, whose 1,632-page book ‘‘Reclaiming History: The Assassination of President John F. Kennedy’’ was published in May.

Bugliosi’s book comes to the opposite conclusion: Lee Harvey Oswald shot Kennedy, and he did it on his own.

Bugliosi said he thinks a majority of Americans believe in some sort of conspiracy surrounding the assassination or the investigating Warren Commission, but most of the questions he has fielded on his book tour revolve around the suspicions of CIA or mob involvement.

‘‘They believe in a conspiracy,’’ he said, ‘‘and I think (the survey) allowed them to express their beliefs.’’

The survey was conducted by telephone Sept. 24 to Oct. 10 among 811 adult residents of the United States who were selected at random. The survey was conducted by the Scripps Survey Research Center at Ohio University under a grant from the Scripps Howard Foundation and has a margin of error of about 4 percent.





Here are selected findings from a national survey of 811 adult residents of the United States conducted by Scripps Howard News Service and Ohio University.

I’d like to ask about some conspiracy theories that are sometimes mentioned among Americans. Please tell me whether you think each of these are very likely, somewhat likely or unlikely. So when I say that oil companies are conspiring to keep gasoline prices high, is that very likely, somewhat likely or unlikely?

Very Likely ...................... 50

Somewhat Likely................ 31

Unlikely............................. 14

Don’t Know/Other ............ 5 How about that some people in the federal government had specific warnings of the 9/11 attacks in New York and Washington, but chose to ignore those warnings. Is this very likely, somewhat likely or unlikely?

Very Likely....................... 32

Somewhat Likely................ 30

Unlikely............................. 30

Don’t Know/Other...................... 8

How likely is it that some people in the federal government knew about the assassination of President Kennedy in advance?

Very Likely ...................... 20

Somewhat Likely .............. 22

Unlikely ............................ 41

Don’tKnow/Other ............ 17

How likely is it that some people in the federal government have proof that there is intelligent life from other worlds?

Very Likely ...................... 10

Somewhat Likely .............. 27 Unlikely ......................... ...58

Don’tKnow/Other ............. 5

Some Americans feel that flying saucers are real and that the federal government is hiding the truth about them from you. Is this very likely, somewhat likely or unlikely?

Very Likely ...................... 12

Somewhat Likely .............. 25

Unlikely ............................ 56

Don’t Know/Other ........... 7