Poll: 2 in 3 voters say it's 'likely' that people lie when taking political surveys

About two in three voters say they think it is likely that a significant number of people are not truthful when responding to political surveys, a new Hill-HarrisX poll finds.

Sixty-six percent of registered voters in the Aug. 29-31 survey said it is either very or somewhat likely that a significant number of people lie when talking political surveys, compared to 34 percent who said it is unlikely.

The survey found broad agreement across demographic groups over how people approach political surveys, though Democrats in the poll were less likely than Republicans to say that people lie in polls.

Sixty percent of Democratic voters said they think people lie when responding to political surveys, compared to 70 percent of Republican voters and 67 percent of independent voters who said the same.

The survey follows post-convention polling that has shown Democratic nominee Joe BidenJoe BidenBiden offers support to union organizing efforts Senate Democrats nix 'Plan B' on minimum wage hike Kavanaugh dismays conservatives by dodging pro-Trump election lawsuits MORE maintaining a lead over President TrumpDonald TrumpSacha Baron Cohen calls out 'danger of lies, hate and conspiracies' in Golden Globes speech Sorkin uses Abbie Hoffman quote to condemn Capitol violence: Democracy is 'something you do' Ex-Trump aide Pierson planning run for Congress MORE nationally, though Trump has seen his numbers tick up in some areas.

Some political observers have questioned whether polls undercount GOP support and if some respondents may not fully reveal their support for Trump when taking a survey, making his support appear lower than in reality.

An Aug. 19-27 study conducted by CloudResearch, an online market research and data collection company, found that roughly 11 percent of Republican voters and 10 percent of independent voters said they would not report their true opinions about their preferred presidential candidate on telephone polls.

Emily Ekins, research fellow and director of polling at the Cato Institute, noted that some differences may also emerge when a person is speaking with a pollster on the telephone compared to completing an online survey.

"People feel social desirability bias where they might lie about certain opinions they might have or who they're going to vote for," Ekins told Hill.TV.

"But a lot of our surveys today are conducted online including this survey and in those cases I think there's a lot less evidence that people are going to be lying about their responses when there's no one else on the other line," she added.

The Hill-HarrisX poll was conducted online among 971 registered voters. It has a margin of error of 3.1 percentage points.

Gabriela Schulte