Should I Take a Lie Detector Test at Work?
When your boss asks you to take a lie detector test, do you have to do it? Should you do it? Read on to learn your rights and one lawyer's advice.
“Mr. Beaver, I am in upper management at a high-quality meat processing plant in the Midwest. Over the past several months we have experienced a significant loss of expensive sides of beef, but it has not been continuous, just time to time.
“I have an idea who is behind this theft. I believe it is a group of employees, but can’t say for sure. It is more than a feeling, more than a hunch, but I do not have real evidence of who is doing what,” “Jody” wrote.
“Our CEO wants to run all employees on a polygraph to be administered by a private investigator. Am I legally obligated to submit to the examination? What happens if I refuse? Can I be terminated? What has been your experience in your law practice with the polygraph? Do you believe that it accurately can detect who is telling the truth? Are some people more likely than others to fail the test?”
From just $107.88 $24.99 for Kiplinger Personal Finance
Become a smarter, better informed investor. Subscribe from just $107.88 $24.99, plus get up to 4 Special Issues
Sign up for Kiplinger’s Free Newsletters
Profit and prosper with the best of expert advice on investing, taxes, retirement, personal finance and more - straight to your e-mail.
Profit and prosper with the best of expert advice - straight to your e-mail.
Some Facts about Polygraph Examinations
The first polygraph dates from 1920, when a California-based policeman and physiologist, John A. Larson, developed an instrument to measure continuous changes in blood pressure, heart rate and respiration rate in order to aid in the detection of deception. The operative theory was that your body’s own reactions would reveal lying.
Until 1988, lie detectors were routinely used on employees and job applicants, and they still are for certain types of employment. Employers often asked employees and applicants questions about private matters — often having nothing to do with the actual job — and the lie detector would reach a conclusion as to their honesty. Even people who were truthful often appeared, to the machine, as deceptive.
Eventually the accuracy of polygraph tests came to be seriously doubted. The Federal Employee Polygraph Protection Act, passed in 1988, virtually outlawed using lie detectors in connection with employment. Under the act, it is illegal for private companies to:
- Require, request, suggest or cause any employee or job applicant to submit to a lie detector test;
- Use, accept, refer to or inquire about the results of any lie detector test conducted on an employee or job applicant, or;
- Dismiss, discipline, discriminate against or even threaten to take action against any employee or job applicant who refuses to take a lie detector test.
The law also prohibits employers from discriminating against or firing those who claim its protections. Government employees are generally not protected by this law, however civil service rules offer some protection.
When Lie Detector Tests May Be Used
The Employee Polygraph Protection Act permits polygraph tests with jobs in security and handling drugs or in investigating theft or other crimes committed by employees. Before an employee can be required to take the test, a 48-hour notice must be provided, which states that you are a suspect. A provable, reasonable suspicion that you were involved in the theft or other conduct triggering the investigation must be established.
It is important to note that an employee may refuse to take the test. Additionally, the act’s protections do not apply to employees of federal, state or local government, nor to certain jobs that handle sensitive work relating to national defense.
State laws often further restrict the ability of running an employee on the polygraph, so that is something important to look into.
Controversial at Best
Some years ago, the American Psychological Association issued this statement:
“The accuracy (i.e., validity) of polygraph testing has long been controversial. An underlying problem is theoretical: There is no evidence that any pattern of physiological reactions is unique to deception. An honest person may be nervous when answering truthfully and a dishonest person may be non-anxious. Also, there are few good studies that validate the ability of polygraph procedures to detect deception.”
Our Own Experience
Years ago, I taught part-time at California State University in Bakersfield and invited the D.A. Office’s polygrapher to demonstrate how the machine worked to the class. One member was selected. He was an “Army Brat,” having lived in several countries, and spoke Spanish, French and German. We heard him speak those languages.
Hooked up to the machine, he was asked if he spoke those languages, and replied affirmatively. The machine said “Deceptive!” On it went, he gave honest answers, yet the machine called him a liar.
“So, how do you explain this?” I asked the polygrapher.
“Some cultures (or families) where guilt is a strong influence in the raising of children can dramatically influence how someone will do on a polygraph, and I’ve seen this before,” he commented.
With that experience in mind, my advice to Jody would be to politely decline being tested on the polygraph. While innocent, that scent of suspicion could do him great harm.
Profit and prosper with the best of Kiplinger's advice on investing, taxes, retirement, personal finance and much more. Delivered daily. Enter your email in the box and click Sign Me Up.

After attending Loyola University School of Law, H. Dennis Beaver joined California's Kern County District Attorney's Office, where he established a Consumer Fraud section. He is in the general practice of law and writes a syndicated newspaper column, "You and the Law." Through his column, he offers readers in need of down-to-earth advice his help free of charge. "I know it sounds corny, but I just love to be able to use my education and experience to help, simply to help. When a reader contacts me, it is a gift."
-
4% and Chill? Find Out If This Distribution Rule Fits Your RetirementTake this simple quiz to discover whether the 4% Rule will work for you in retirement.
-
Oregon Tax Kicker in 2026: What's Your Refund?State Tax The Oregon kicker for 2025 state income taxes is coming. Here's how to calculate your credit and the eligibility rules.
-
Will IRS Budget Cuts Disrupt Tax Season? What You Need to KnowTaxes The 2026 tax season could be an unprecedented one for the IRS. Here’s how you can be proactive to keep up with the status of your return.
-
I'm an Estate Planning Attorney: These Are the Estate Plan Details You Need to Discuss (And What to Keep Private)Gen Xers and Millennials would like to know if they're going to inherit (and how much), but Baby Boomers in general don't like to talk about money. What to do?
-
I'm a Financial Adviser: This Is How You Can Minimize the Damage of Bad Market Timing at RetirementPoor investment returns early in retirement on top of withdrawals can quickly drain your savings. The ideal plan helps prevent having to sell assets at a loss.
-
'You Owe Me a Refund': Readers Report Challenging Their Attorneys' BillsThe article about lawyers billing clients for hours of work that AI did in seconds generated quite a response. One law firm even called a staff meeting.
-
7 Questions to Help Kick Off an Estate Planning Talk With Your ParentsIt can be hard for aging parents to discuss estate plans — and for adult kids to broach the topic. Here are seven questions to get the conversation started
-
What Not to Do After Inheriting Wealth: 4 Mistakes That Could Cost You EverythingGen X and Millennials are expected to receive trillions of dollars in inheritance. Unless it's managed properly, the money could slip through their fingers.
-
'The Money Prism' Solves Retirement Money's Biggest Headache: Here's HowThis simple, three-zone system (Blue for bills, Green for paycheck, Red for growth) helps you organize your retirement savings by purpose and time.
-
No, AI Can't Plan Your Retirement: This (Human) Investment Adviser Explains WhyAI has infinite uses. But creating an accurate retirement strategy based on your unique goals is one place where its possibilities seem lacking.
-
Don't Let a 60/40 Portfolio Derail Your Retirement: Why a Cookie-Cutter Approach Could Cost YouChoosing a personalized retirement investment plan, rather than relying on the 60/40 portfolio, could help protect your savings and ensure long-term growth.