What is Undue Influence?

Mary McMahon
Mary McMahon

Undue influence is power over someone else which is used to push the weaker person into making a decision which would not otherwise have been made. A classic example of a situation in which undue influence might be used is in the drafting of a will. Someone could pressure the testator to include a legacy or gift which the testator had no intention of including originally, using a variety of manipulative tactics such as trickery, flattering, or suggestion.

Manipulating someone into drafting a will in one's favor is an example of undue influence.
Manipulating someone into drafting a will in one's favor is an example of undue influence.

Under the law, if it can be demonstrated that a contract, will, or other document was made in circumstances in which undue influence was involved, it can be set aside. In the case of a contract, for example, the person who was influenced will not be held to the contract. With documents like wills, family members may challenge the document in probate because they believe that it does not truly represent the intentions of the deceased.

The relationship between doctor and patient might be more prone to undue influence.
The relationship between doctor and patient might be more prone to undue influence.

Certain types of relationships are believed to be especially prone to undue influence by their nature, such as spousal relationships, parent/child relationships, doctor/patient relationships, and religious officiant/parishioner relationships. In other instances, the relationship between the two people is not necessarily one where this type of influence is presumed to be present, but evidence can be presented to show that it occurred.

Parent/child relationships are among those believed to be especially prone to undue influence.
Parent/child relationships are among those believed to be especially prone to undue influence.

Several things can point to the presence of undue influence in a transaction. The first is the existence of a transaction or agreement which appears odd and out of character. For example, if a woman donates to an opposition political party in her will, this might raise a red flag. Being in a position of vulnerability or susceptibility is another warning sign. In the example above, for instance, if the woman was elderly and heavily reliant on a caregiver in her home, this could mean that the caregiver had influenced her.

Next, there must be evidence of opportunity. If it can be shown that someone in a position to have undue influence had opportunities to use it, this can indicate that a questionable transaction may be the result of that influence. Finally, evidence is required. It can be tricky to muster evidence because people using manipulation in transactions tend to keep their activities quiet because they do not want to be caught.

This is not the same thing as duress. In duress and coercion, people are physically threatened or subjected to physical violence in order to achieve a desired outcome. Undue influence does not involve violence or threats of violence, relying on other manipulative techniques instead.

Undue influence is common in peer groups.
Undue influence is common in peer groups.
Mary McMahon
Mary McMahon

Ever since she began contributing to the site several years ago, Mary has embraced the exciting challenge of being a wiseGEEK researcher and writer. Mary has a liberal arts degree from Goddard College and spends her free time reading, cooking, and exploring the great outdoors.

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Discussion Comments


I wonder if blackmailing would fall under the category of undue influence? It isn't a physical threat or coercion, but it is definitely a strong motivator.

My uncle was blackmailed into signing a contract that gave his business partner the majority of the control over the business. He had some information on my uncle that would have destroyed his reputation and his marriage if it had come to light, so he felt he had no choice but to sign over the business to his partner.

His wife could never get a clear answer out of him about why he did this, and he never challenged the guy in court. He would do anything to keep his past deeds private, but he did let my dad know that the decision had not been his to make.


My family felt that my aunt had experienced undue influence in the drafting of her will. She had been a pro-life activist for many years, and at the reading of her will, we were all shocked to hear that she had decided to donate money to the pro-choice movement.

During her last year, she had been living with a caregiver whom none of us trusted. My aunt had begun to lose her mental capacity toward the end, and we are sure that this must have been when she did her will. We believe that her caregiver had undue influence over her, because we knew that this woman was very pro-choice and involved in the politics of it all.

We challenged this, and the judge sided with us. It helped that my aunt's doctor testified that she had dementia and could not possibly have had the ability to soundly draw up a will.


@seag47 – I see your reasoning, but I have to disagree because of what happened to my poor old grandfather. He fell in love with a woman forty years younger than he was, and his love truly blinded him to the fact that she was after his property and money.

She had him sign a prenuptial agreement, which should have been a red flag to him. He just considered himself so lucky to have her that he would have agreed to anything.

Well, the marriage ended, and she wound up getting the house and a sizable chunk of money. I think this was a clear case of undue influence, but he was too brokenhearted to challenge the document in a court of law.


Undue influence sounds a bit fishy to me. If a person isn't held at gunpoint or otherwise threatened or blackmailed into doing something, then how can it be deemed invalid or illegal?

I know that there are people out there who are very tricky and manipulative, but the decision to include something in a will or contract is ultimately that of the person writing or signing it. How can you really say that the person is not at fault? Unless the writer of the document is mentally handicapped in some way, they should be held to what they agree to, in my opinion.

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