Suspicions of Undue Influence by Sister Over 89 year-old Mother

Reader’s Question

Several of my brothers and sisters, including myself, feel our mother (89 years old) is suffering from severe undue influence…perhaps even Stockholm Syndrome…at the hands of our oldest sibling, a sister who is 68. This feeling has been around for many years although it has gotten stronger since our oldest sibling (female and single, never married, no children) has physically moved to the same home town as our mother and is in her home 99% (?) of the time, although she has her own apartment in the same town. There has been a heavy reliance on mother financially and in other ways which are too numerous to mention here. Our oldest sister has said that those of us who feel this way have a moral obligation to get it checked out. Question: What types of personality or psychological testing can be done with our mother to check out our feelings? What about on the sister whom we feel is at the heart of this matter? What can be done and at whose expense?

Our Consulting Clinical Psychologist’s Reply

There is no question that the primary caretaker (the 68 y/o sister) will have more influence over your mother than her other children. The question is: is it unhealthy? The situation you describe is also not uncommon — this sister spending most of her time with your mother and even depending upon her for some financial support. Their relationship is mutually-supporting and cures the loneliness both would have if they lived independently but alone. It’s also not uncommon for some suspicion and even resentment to surface in the siblings, especially when Mother’s finances are involved.

However, the key issue is the “range” of influence. Stockholm Syndrome would suggest that your mother is a captive who agrees with or supports the oldest sister due to fears for her safety and survival. This is probably unlikely unless your sister is known to be physically abusive or intimidating. The idea of “severe undue influence” suggests you suspect a relationship that is emotionally unhealthy, manipulative, unethical, or even criminal. Questions that frequently arise are:

• Has she influenced your mother to change her will?
• Has she convinced your mother that the other children are out to harm or manipulate her?
• Is the sister taking advantage of mother financially?
• Is the sister engaged in criminal activity such as stealing money, selling jewelry, etc.?

Perhaps bigger questions:

• Has your mother complained about the current arrangement?
• Is your mother competent to make financial and social decisions in her own behalf?
• Is your mother exhibiting signs of abuse or intimidation?

If you and your siblings are concerned about the undue influence or a secret agenda on the part of your older sister, the burden of proof is your responsibility. Assuming your mother is not currently under legal guardianship or has been declared incompetent, you would need her approval before contracting for a psychological or psychiatric examination. This is also true of your sister as you cannot have her examined/evaluated without her permission unless criminal/civil charges have been filed — and then the court must order such an examination. Even if both your mother and older sister consented to clinical assessments — which is unlikely — you would next be required to file a court action. In court, again, the burden of proof and all expenses would be yours.

From your description, it sounds like the sister in question has always relied on Mother for financial support, something that often creates resentment in siblings. At 68 years of age, she may still require the support of your mother — exchanging that support for almost 24 hour caretaking. Your mother has a right to support her and allow her to live in her home. In this situation, the court’s major concern would be the best interests of your mother. Unless you can prove abusive or criminal behavior, there is very little you can do. You might consult an attorney, as laws vary from country to country and in the US, from state to state.