Millions of Americans have signed away their constitutional rights by entering into routine contracts with credit card companies and other firms. But do they understand what they're agreeing to?

Companies use arbitration clauses to insulate themselves from litigation by consumers and employees. These clauses typically take away constitutional rights such as suing in court and pursuing a trial by jury and other rights like participating in class actions, which are sometimes the only cost-effective way for consumers to obtain redress. Only people who have agreed to such a clause can be forced to arbitrate. So businesses insert these provisions into seemingly ho-hum contracts.

To find out how well Americans comprehend arbitration clauses, my colleagues Elayne Greenberg, Paul Kirgis, Yuxiang Liu and I recently surveyed 668 consumers chosen to reflect the country's demographics. (The survey was supported by a grant from the American Association for Justice Robert L. Habush Endowment.) We showed the consumers a credit card contract with a typical arbitration clause-one that said in bold print, italics, and capital letters that it prevented consumers from litigating in any court other than a small claims court and from entering into a class action or having a jury trial. Then we asked survey participants eight questions about arbitration clauses.

As we expected, few respondents realized that they were giving up their rights. But even we were surprised by how many people suffered from serious misconceptions. For example, four times as many respondents believed that they could bring a class action under the contract as those who recognized that they could not. Similarly, more than three times as many respondents thought they could still go to court, even though the contract blocked access. As one person put it, many participants assumed that "a whimsy little contract" couldn't take away their rights. Yet the Supreme Court has ruled that a contract can do exactly that.

While 43% of the respondents recognized that the sample contract included an arbitration clause, few understood what that meant. Less than 9% realized both that the contract had an arbitration clause and that the clause would prevent consumers from suing in court. As Nobel Prize-winning physicist Richard Feynman once observed, knowing the name of something is not the same as knowing what it is.

Overall, only two of the 663 respondents who answered all eight questions about the arbitration clause answered all the questions correctly, while 117 failed to answer any correctly. If this had been a test requiring the usual grade of 65% to pass, 96% of the respondents would have failed.

We also asked respondents if they had ever personally agreed to an arbitration clause. Then we inquired whether they had entered into contracts with companies like Verizon Wireless or PayPal, which have arbitration clauses in their contracts.

Of the 303 respondents who claimed they had never agreed to arbitrate, 87% did indeed have at least one account subject to an arbitration clause. Many participants had more. Nor can we say that the remaining 13% have not agreed to a contract with an arbitration term, since they might have done so in some other contract we didn't ask about.

The results of this survey suggest that the consent consumers provide when they sign a contract taking away their right to sue is no more meaningful to most consumers than if the clause had been printed in a foreign language.

The Consumer Financial Protection Bureau is currently studying pre-dispute arbitration clauses to see if it should regulate their use in financial contracts. If the CFPB finds that consumers don't understand the rights those clauses take away, as our survey suggests it will, it should prohibit their use as lacking legitimacy. Congress should go further by banning the use of pre-dispute arbitration clauses in other consumer contracts.

Even those unconvinced by the particulars of our study should be concerned in light of what is at stake. Arbitration clauses are different from many other contract provisions because they strip away constitutional rights and enable wrongdoers to avoid taking responsibility for their actions. People should not forfeit critically important rights by signing whimsy little contracts that they don't understand. It's time to put an end to such tricks and traps.

Jeff Sovern is a professor of law at St. John's University and a coordinator of the Consumer Law and Policy Blog.