Relationship uncertainty can be highly distressing. When trust has been damaged, some people consider a lie detector test or polygraph examination because they want clarity about a specific issue. However, asking a partner to take a polygraph is a significant step and should be approached carefully.
A polygraph examination may provide investigative information about a clearly defined issue, but it is not a test of love, commitment, character or future fidelity. It should not be used to pressure, punish or control a partner. Informed consent, careful question formulation and suitability assessment are essential. Dr Keith Ashcroft, Principal Forensic Polygraph Examiner at the Centre for Forensic Neuroscience, considers relationship and infidelity polygraph enquiries after a confidential discussion about suitability, consent and scope.
Why People Consider a Partner Lie Detector Test
People consider asking a partner to take a lie detector test for many reasons, including:
- Suspected infidelity or sexual contact outside the relationship
- Incomplete disclosure after an admission
- Conflicting accounts of events
- Online messaging or dating app concerns
- Pornography or sexual behaviour concerns where relevant
- Financial dishonesty
- Secret contact with another person
- Breach of an agreed relationship boundary
- Rebuilding trust after an admission
- Resolving a specific factual dispute
Whatever the reason, the issue must be capable of being clearly defined. A polygraph examination is not a general investigation into someone’s character, feelings or relationship commitment.
A Polygraph Is Not a Test of Love or Commitment
A polygraph examination cannot answer questions such as:
- “Do they love me?”
- “Can I trust them forever?”
- “Will they cheat again?”
- “Are they truly sorry?”
- “Are they a good partner?”
- “Do they care about the relationship?”
- “Will they change?”
These are emotional, relational or future-focused concerns. They are not suitable polygraph questions. For guidance on what can and cannot be asked, see our article on infidelity polygraph test questions.
When Might It Be Reasonable to Discuss a Polygraph?
It may be reasonable to discuss a relationship polygraph examination where:
- There is a specific factual issue
- Both people understand the purpose and limitations
- The examinee can give free and informed consent
- The questions can be behaviourally defined
- The process is not being used as punishment
- There is no intimidation or coercion
- The result will be considered alongside the wider context
- Both people understand that the polygraph cannot guarantee relationship outcomes
Examples of Clearer Issues
- Whether sexual contact occurred with a named person
- Whether contact continued after an agreed date
- Whether a dating app was used for sexual contact
- Whether money was spent on a specific hidden activity
- Whether a specific disclosure is complete within an agreed timeframe
Important: Actual questions should only be finalised after proper discussion with the examiner.
When Asking May Be Unhelpful or Unsafe
Asking a partner to take a polygraph may be unsuitable where:
- There is coercion, fear or intimidation in the relationship
- The relationship involves controlling behaviour
- The request is made as a threat or ultimatum
- There are safeguarding concerns
- The issue is vague or emotionally loaded
- The desired question is about feelings or future behaviour
- The result will be used to shame, punish or humiliate
- Either person expects the test to solve the relationship on its own
- There are legal, family court, employment or safeguarding issues requiring professional advice
A professional examiner should be willing to decline unsuitable cases. A refusal to proceed can be a sign of professional integrity.
Consent Matters
Informed consent is essential. The examinee must understand the process, and relevant questions should be discussed before testing. Surprise questions are not used in a professional polygraph examination. The person should not be forced or threatened into agreeing.
A partner agreeing to a polygraph because they feel frightened, trapped or threatened is not the same as informed consent.
Consent must be meaningful — not merely reluctant compliance under pressure.
Does Refusing a Lie Detector Test Mean Someone Is Guilty?
No. Refusal does not automatically prove guilt. A person may refuse for many reasons, including:
- Anxiety about the process
- Concern about being pressured
- Distrust of the process or the technology
- Legal advice
- Fear of relationship consequences regardless of the result
- Misunderstanding about what polygraph involves
- Not accepting the premise of the accusation
- Feeling the request is unfair or coercive
Similarly, agreeing to take a test does not automatically prove innocence. The result should be considered alongside the wider context.
How to Raise the Subject Responsibly
If you are considering discussing a polygraph with your partner, approach the conversation carefully:
- Choose a calm time, away from an argument
- Avoid threats, ultimatums or public pressure
- Explain the specific issue, not every grievance
- Acknowledge the limits of polygraph testing
- Allow the other person time to consider
- Encourage independent advice where legal, therapeutic or safeguarding issues exist
- Do not demand immediate agreement
- Focus on whether the issue can be properly scoped
If you are uncertain about whether a polygraph is suitable for your situation, a confidential discussion with the examiner may help clarify the options.
What Questions Could Be Suitable?
Suitable questions are specific, behaviourally focused, time-limited, clearly understood, agreed before testing, and linked to the agreed issue. Examples include:
- “Since [date], have you had sexual contact with anyone other than [partner]?”
- “Since [date], have you had physical sexual contact with [named person]?”
- “Since [date], have you used [specific dating app] to arrange sexual contact?”
- “Since [date], have you sent sexual messages to [named person]?”
- “Since [date], have you met [named person] for sexual purposes?”
These are illustrative only. Actual wording should be developed after a case discussion with the examiner. For more detail, see our guide on infidelity polygraph test questions.
What Questions Are Usually Unsuitable?
- “Do you love me?”
- “Are you sorry?”
- “Can I trust you?”
- “Will you cheat again?”
- “Are you hiding anything?”
- “Have you ever lied to me?”
- “Are you a narcissist?”
- “Are you a bad person?”
- “Do you still have feelings for them?”
These are vague, emotional, subjective, future-focused or character-based. They are not suitable for polygraph testing because they cannot be reduced to a clear, behaviourally specific question with a defined timeframe.
What If the Relationship Involves Therapy or Disclosure Work?
Some clients consider polygraph as part of a disclosure or behavioural accountability process. In this context:
- The polygraph examiner is not providing therapy or counselling
- The process should not replace therapeutic support
- The scope must be carefully defined
- Communication with therapists or counsellors should only occur with appropriate consent and boundaries
- The examination should support clarity about specific behaviour, not act as relationship counselling
What If There Are Legal, Safeguarding or Family Issues?
If the matter involves criminal allegations, domestic abuse concerns, safeguarding, child contact, family court, employment consequences, harassment or coercive control, or threats of harm, the person should seek appropriate professional advice before relying on a polygraph process.
A polygraph examination should not replace legal advice, safeguarding procedures or professional risk assessment. Where legal issues are involved, see our page on polygraph examinations for solicitors and barristers.
What Happens If the Case Is Suitable?
If the matter is suitable for a polygraph examination, the process typically involves:
- A confidential enquiry
- A suitability assessment
- Discussion of the issue and relevant behaviour
- Scope and timeframe clarification
- Question formulation
- Pre-test interview
- Informed consent
- The polygraph examination
- Analysis and result explanation
- Written report where appropriate
For guidance on what to expect, see our article on how to prepare for a polygraph examination.
How Results Should Be Used
Polygraph results should be treated as investigative information. They should not be used:
- As a weapon against a partner
- As automatic proof of truth or deception
- As a substitute for wider evidence or professional advice
- As the sole basis for major relationship or legal decisions
- As a guarantee that trust will return
Results may help clarify a specific issue when interpreted responsibly and considered alongside the wider relationship context.
Alternatives or Additional Steps to Consider
Depending on the circumstances, you may also benefit from:
- Relationship counselling or therapy
- Legal advice where relevant
- Safeguarding advice where relevant
- HR or employment advice where workplace issues are involved
- Time-limited disclosure conversations
- Documented agreements about relationship boundaries
- Support from an appropriate professional
This article does not provide therapeutic, legal, safeguarding or medical advice. These suggestions are included for general awareness only.
Why Clients Contact Dr Keith Ashcroft
Dr Keith Ashcroft considers relationship and infidelity polygraph enquiries through the Centre for Forensic Neuroscience. Clients contact Dr Ashcroft because he provides:
- A confidential initial discussion before any appointment is accepted
- Careful suitability assessment
- Informed consent and professional boundaries
- No surprise questions
- Careful question formulation tailored to the specific concern
- A written report where appropriate
- Results explained within appropriate limits
Examinations may be arranged at suitable professional venues in Manchester, Preston, London, Birmingham, Edinburgh or elsewhere in the UK. For information on polygraph examination costs, see our dedicated article. For guidance on selecting an examiner, see how to choose a polygraph examiner in the UK.
Conclusion
Asking a partner to take a lie detector test may be appropriate in some clearly defined situations, but it should be done carefully, ethically and without coercion. The process is most useful where there is a specific factual issue, informed consent, appropriate question formulation and realistic expectations about what the polygraph can and cannot do.
A polygraph examination is not a relationship fix, a guarantee of truth, or a tool for control. It is a structured forensic procedure that may provide investigative information about a defined issue — and it works best when both people understand its purpose and its limits.
Frequently Asked Questions
Should I ask my partner to take a lie detector test?
It may be appropriate to discuss a polygraph examination where there is a clear, specific factual issue, informed consent and suitable question formulation. It should not be used to pressure, punish or control a partner.
Does refusing a lie detector test mean my partner is guilty?
No. Refusal does not automatically prove guilt. A person may refuse for many reasons, including anxiety, legal advice, distrust of the process, concern about pressure or disagreement with the premise of the accusation.
Can a polygraph prove my partner loves me?
No. A polygraph cannot test love, commitment, remorse or future loyalty. Questions should focus on specific past behaviour, not emotions or promises.
Are surprise questions used in a relationship polygraph?
No. Relevant questions should be discussed and understood before the examination. Surprise questions are not used in a professional polygraph examination.
Can a polygraph help after infidelity?
It may help clarify specific factual issues, such as whether particular behaviour occurred within a defined timeframe. It cannot repair trust by itself or replace counselling, legal advice or personal decision-making.
What if my partner feels pressured?
If a person feels coerced, frightened or threatened, a polygraph examination may be unsuitable. Informed consent and safety are essential.
What questions can be asked?
Questions should usually concern specific past behaviour, such as sexual contact, contact with a named person, dating app use or agreed relationship boundaries within a defined timeframe. For more detail, see our article on infidelity polygraph test questions.
Can the result decide whether I should stay in the relationship?
No. The result may provide investigative information, but relationship decisions should consider the wider context and, where appropriate, support from relevant professionals.
Important Disclaimer
This article is provided for general educational and consumer information only. It does not constitute therapeutic advice, relationship counselling, legal advice, safeguarding advice, or medical advice. Polygraph results are investigative information and should not be treated as absolute proof of truth or deception. They do not replace counselling, legal advice, safeguarding procedures, workplace investigations or personal decision-making. No solicitor-client, therapeutic or professional-client relationship is created by this publication.
Dr Keith Ashcroft is the Principal Forensic Polygraph Examiner at the Centre for Forensic Neuroscience. For professional enquiries concerning relationship and infidelity polygraph examinations, contact Dr Keith Ashcroft.