The Lucid Interval in Testation: Scientific Fact or Legal Fiction?

Eric G. Mart, Ph.D., ABPP  |  July 21, 2016

While there have been a variety of standards for determining whether a testator has or had the requisite mental state to create a valid will, the standard used in nearly every jurisdiction in the United States draws heavily on the 1870 case of Banks v. Goodfellow. This British case was decided by Lord Henry Cockburn, who defined the standard for testamentary capacity as summarized below:

  • The testator understands the nature and purpose of a will and also understands that he or she is creating such a document.
  • The testator understands the probable impact of the distribution of his or her assets on the individuals involved.
  • The testator understands the extent of his or her property.
  • The testator recalls the identities of the natural objects of his or her bounty (e.g., the individuals who, all things being equal, would likely be the recipients of the testator’s distribution of assets).
  • The testator’s decisions regarding this distribution are not the product of delusion or other mental illness; he or she is of sound mind.

With regard to the last criteria, it must be understood that at the time these criteria were promulgated, no clear distinction was made in the law between metal unsoundness caused by what are sometimes referred to as functional mental illnesses (e.g., schizophrenia, bipolar disorder, seasonal affective disorder) and organic processes such as dementia or delirium. There were also various legal cases in which the concept of the lucid interval was introduced. An early definition of this concept was outlined in The Practice in Proceedings in the Probate Courts of Massachusetts: With an Appendix of Uniform Forms and Rules Approved by the Supreme Judicial Court, by William L. Smith (fifth edition, revised by Arthur Lord, with additional forms and rules, and a digest of statutes from 1894-1899):

"Lucid Intervals. — The party supporting the will may show that the testator, although insane at some period of his life, had recovered his reason, or that the will was made during a temporary cessation of the insanity. Lunatics occasionally recover for a time, and are conscious of their acts. The lucid interval may be a few hours or minutes in duration, or it may continue for weeks, months, and even years. Evidence of a lucid interval is to be examined with great caution, especially in cases where the alleged interval was of brief duration. A mere diminution in the violence of the disorder does not constitute a lucid interval. It need not, of course, appear that the predisposition to the disease had been extirpated, or that the testator had regained the same degree of intellectual ability that he possessed previous to his insanity; but it must appear that he was conscious of his acts, and able to understand their nature and consequences. The fact that the will is a rational one and made in a rational manner, though not conclusive, is strong evidence that it was made in a lucid interval.

"In establishing the fact of a lucid interval, evidence has been admitted to show that the disposition of the testator's property made by his will was consistent with his intentions declared previous to his insanity."

The concept of the lucid interval has been used in many cases to support the validity of a will that has been challenged. In certain conditions, this can be a valid approach. Individuals with a variety of acute conditions can experience significant fluctuations in cognitive status. Persons who are experiencing acute exacerbations of condition such as psychosis or an affective disorder can rapidly improve if properly treated with medications and psychotherapy. In the same way, individuals who develop acute delirium due to physical illness, polypharmacy or other toxicities may rapidly return to baseline when their underlying conditions are addressed. However, the idea of lucid intervals in individuals with dementing conditions such as Alzheimer’s disease or vascular dementia has also been raised with some frequency in cases in which a will made by an individual with one of these conditions is being defended. The underlying premise for these types of defenses is that individuals with dementing conditions have good days and bad days, and the will in question was created on one of the good days.

The belief that individuals suffering from dementia exhibit significant fluctuations in the severity of their conditions appears to proceed from the observations of caregivers or primary care physicians who notice that a particular patient seems more alert and tuned in at times. But does research support the idea that an individual suffering from dementia might episodically improve sufficiently to create a valid will even though at baseline the individual would not meet the Banks v. Goodfellow criteria? A recent paper by Kenneth Shulman et al. (2015) suggests that this is seldom the case. These authors note that the available research indicates that, while some fluctuations in mental status can occur, they tend to quite brief and to occur primarily in the areas of attention and alertness. Cognitive fluctuations in those areas essential to testamentary capacity, such as executive functioning and episodic memory, were not seen to occur to any significant degree, and when they do they are of such limited duration as to be too short for a will to be completed. A possible exception to this is seen in individuals suffering from dementia with lewy bodies, where cognitive fluctuations are seen with more frequency, but there is little evidence that these fluctuations are sufficient to constitute a lucid interval.

Based on this research, it appears that the concept of individuals with dementia experiencing lucid intervals sufficient to restore testamentary capacity is not supported by contemporary science. Shulman et al. suggest that further research is necessary to clarify the validity of the idea of lucid intervals in testation, and that reports by caregivers that a will was created during such an interval be carefully scrutinized in probate matters.


Shulman, Kenneth I., Ian M. Hull, Sam DeKoven, Sean Amodeo, Brian J. Mainland, and Nathan Herrmann. “Cognitive Fluctuations and the Lucid Interval in Dementia: Implications for Testamentary Capacity.” The Journal of the American Academy of Psychiatry and the Law, 43(3) (September 2015): 287–92.

Functional Capacity vs. Psychiatric Diagnosis: A Neglected Distinction

Eric G. Mart, Ph.D., ABPP  |  July 14, 2013

Forensic psychologists receive many different types of referrals, but the underlying psycho-legal question is often the same: Does the person have the ability to do what we need him or her to do, and if not, can any deficiencies be treated? This question arises in many court-related contexts:

  • Can this person understand the issues involved in standing trial and assist his or her attorney?
  • Is this person able to parent adequately?
  • Can this child learn effectively in this school environment?
  • Can this adult manage his or her own financial affairs?
  • Does this person have enough understanding of his or her medical/psychiatric condition to give informed consent?

Sometimes the question is retrospective in nature:

  • Did this person know what he or she was doing when he or she changed the will?
  • Did this person understand the wrongfulness of his or her actions when he or she committed the crime?

A problem that I frequently encounter in forensic psychological and psychiatric reports is confusion between functional capacity and psychiatric diagnosis. While this can be seen in many areas of forensic practice, I see it most frequently in cases where guardianship is the issue. Frequently, courts will order neuropsychological assessments for elderly individuals suspected of having dementia or for younger persons with head injuries or low IQs. These reports often provide a great deal of information about many areas of cognitive functioning, including detailed descriptions of the individual’s abilities in areas such as verbal, non-verbal, short-term and long term memory, various aspects of executive functioning, and constructional abilities. Unfortunately basic questions regarding functional capacity, which are the real reason for the referral, are not addressed. For example, can the person balance a checkbook, set up and take his or her medication, or move about the community safely? A neuropsychological evaluation can help explain why observed functional deficits exist, but it generally cannot tell us anything useful about whether functional deficits exist in the first place. The same thing can often be observed in other kinds of reports. For example, the presence of mental retardation or psychosis does not mean that the subject cannot stand trial or parent adequately.

When reviewing court-related mental health reports, lawyers should look for a connection between the data the expert has elicited and his or her conclusions about functional capacity. Often, it is apparent that the expert has not actually assessed functional capacity, and the report may do little to "advance the ball" from an evidentiary standpoint. If this is the case, this deficiency can be brought out, either on cross examination or through the lawyer's own expert.


Greenberg, S., Shuman, D, & Meyer, R. Unmasking forensic diagnosis, International Journal Of Law and Psychiatry, 2004 Jan-Feb;27(1):1-15.

Are Psychological Tests Accurate?

Eric G. Mart, Ph.D., ABPP  |  July 7, 2013

The vast majority of psychologists who perform forensic evaluations utilize psychological testing as part of the assessment process. This raises an important question: Do these tests provide accurate information? The answer to this question is, as with most things in psychology, "It depends."

Psychological tests have a number of measurable qualities that can help us determine whether they provide accurate information. The first of these is reliability. Reliability is a measure of the consistency of test results. For example, if someone is tested and found to have an IQ of 120 today, he or she should have an IQ that is close to 120 six months later if re-tested with the same test. If an IQ test produced widely varying estimates of intelligence over time, it would be unreliable, in the same way that a rubber ruler would be unreliable for measuring distance. There are a number of ways to measure this construct, but a psychological consultant can tell you if a particular test has acceptable levels of reliability.

The second important factor related to test accuracy is validity. The term validity, when used in the context of psychological testing, refers to the extent to which a test measures what it purports to measure. To use the example of an IQ test again, we would expect that individuals with high IQs would perform better in school and produce higher levels of income over their lives, while those with subnormal IQs would have difficulty in school and work in unskilled or semi-skilled trades. In the same way, we would expect that individuals who obtain elevated scores on a measure of depression would exhibit symptoms of depression; if they do not, this may be an indication that the test that was used is not particularly valid.

It should be noted that tests can be highly reliable but have low levels of validity. For example, an IQ test that gives an estimate of intellectual ability based on shoe size would fall into this category. An adult's shoe size is unlikely to vary (reliability), but it is unlikely to tell you much about the intelligence of an individual (validity). On the other hand, it is very unusual for a test to be more valid than it is reliable.

The final factor to be considered is the fit between the test and the construct being measured. If we look at the issue of parenting ability, some tests will be closely connected to this issue and give useful information, while others may not. For example, if the issue is a person's propensity to be physically abusive to young children, the Child Abuse Potential Inventory does a good job of identifying individuals with psychological characteristics that might predispose them to be physically abusive. On the other hand, the Rorschach ink blot test would give you far less information about this specific issue, because the constructs measured by the test are much less directly related to the issue at hand.

Given this information, it may be helpful for attorneys questioning experts to ask about the reliability and validity of each and every test utilized by an expert, and to obtain information about tests from a consultant knowledgeable about psychological tests. In addition, it will be useful to question the expert about any studies that indicate that the test that the expert used is valid in relation to the psycho-legal matter at hand.


Ackerman, Marc J. Essentials of Forensic Psychological Assessment. New York: John Wiley and Sons; 1999.

Interviewing Clients with Borderline Personality Disorder: Tips for Attorneys

Eric G. Mart, Ph.D., ABPP  |  June 29, 2013

Persons diagnosed with personality disorders are a diverse group, and while individual differences are important, diagnostic classifications can be helpful in understanding a particular client's general ways of relating to others and viewing the world. I receive many inquiries from attorneys about how to approach persons with borderline personality disorder, since they can be difficult to interview.

Personality disorders are long-standing maladaptive patterns of thinking, feeling and relating that cause significant distress to the sufferer. Persons with these disorders can also often create problems for those close to them or those working with them, and individuals with borderline personality disorder (BPD) can be particularly challenging. The following description of BPD is adapted from the Handbook of Diagnosis and Treatment of DSM-IV-TR Personality Disorders by Len Sperry, M.D., Ph.D. (2003):

  • Behavioral Style: Resentful, impulsive and prone to acting-out
  • Interpersonal Style: Paradoxical; alternately idealizing and devaluing, rejecting and clinging, sensitive to rejection, fears of abandonment
  • Cognitive Style: Inflexible, rigid and grandiose; failure to learn from experience
  • Feeling Style: Labile in mood and emotion
  • Self Concept: Identity problems which can affect view of loyalties, career, values and gender

Obviously, these characteristics can make it difficult for mental health professionals and lawyers alike to effectively interview individuals with BDP. Rapport is difficult to establish and even more difficult to maintain. Dr. Sperry suggests that these clients will create problems in the interview because of their emotionality, ambivalence and moodiness. He suggests several approaches that may be helpful in these situations. Problems with rapport are best dealt with by addressing apparent problems as they occur in an empathic way. This can be accomplished by directing the discussion, staying on track and firmly redirecting diversions and outbursts. Continuing to process this underlying ambivalence and instability not only helps keep the interview progressing, it also will aid in the development of trust and rapport as the client feels that his or her concerns are being heard. In addition, Dr. Sperry also recommends the use of open-ended questions as opposed to more specific and closed queries. Such an approach will probably not solve all problems, but it will help to minimize disruption of the interview.


Sperry, Len. Handbook Of Diagnosis and Treatment of DSM-IV-TR Personality Disorders. 2nd Ed. New York: Brunner-Routledge; 2003.

The Use of Computers in Psychological Testing

Eric G. Mart, Ph.D., ABPP  |  June 23, 2013

One of the recent advances in psychological testing over the last decade has been the use of computers to both administer and score various types of psychological tests. Years ago, if a psychologist wanted to administer an objective personality test such as the Minnesota Multiphasic Personality Inventory, the subject was given a booklet with hundreds of questions and a "bubble sheet" to record his or her answers. To score the test, the psychologist would laboriously count the responses for each scale using Mylar overlays, and then calculate the scores using the manual and a profile calculation worksheet. This process was time-consuming, and it was easy to make simple scoring errors.

With the advent of the personal computer, the process improved radically. These days, the same tests can be given on the computer, and some versions will even read the questions out loud to the subject if he or she has trouble reading or has visual impairments. Once administered, the test can be almost instantly scored and printed. This process greatly improves accuracy and save a great deal of time. These programs are available for a wide variety of tests of personality and cognitive ability.

But the use of computers for psychological testing also has potential disadvantages which many non-psychologists (and some psychologists) do not understand. One of the most problematic aspects of computerized testing is the indiscriminant use of narrative "canned" reports. Once the test is administered, the psychologist has a number of scoring options. The first of these is to use what is sometimes referred to as a profile report. When this scoring option is used, the psychologist is provided with the scores for the various scales of the test that were administered. Using these scores, the psychologist uses the manual and references to interpret the test.

The other option is for the psychologist to purchase what is sometimes referred to as a narrative or interpretive report. If this option is chosen, the test scores are accompanied by a boilerplate interpretation of the test, sometimes including diagnoses and treatment recommendations. While the use of such reports can be helpful in clinical settings, they are problematic in court-related cases. One such problem is that some psychologists use the computer-generated reports uncritically. With a few exceptions, it is not possible to know if the statements and descriptions in these interpretive reports are based on empirical research or the clinical experience of the author. Consequently, when a psychologist relies on these interpretive reports, he or she has no way of knowing the basis of the interpretations or the accuracy of the statements. A second problem with these reports is that there is a tendency for courts to place undue reliance on the computer-generated statements. Finally, some psychologists have obtained these narratives and simply cut and pasted selected statements directly into their reports. Worse, some mental health professionals wrongly believe that if they do not actually print out the interpretive report it is not discoverable. These practices are very problematic. The unattributed use of portions of the interpretive report is almost certainly a copyright violation, and "hiding the ball" by not producing the report creates ethical and evidentiary problems.

Attorneys who regularly cross examine mental health professionals who use psychological tests can address these problems by taking several steps. Discovery requests should specifically ask for the full printout of any narrative or interpretive reports that were generated in the case, and the expert’s report should be scrutinized side-by-side with the computerized test report. Further, if such interpretive reports were employed and the computer-generated statements incorporated into the expert's report, the expert should be questioned about the underlying research and data that support these interpretations. Awareness of the use of computer-generated reports and a bit of careful inquiry can be helpful in revealing whether the expert used testing to come to scientifically defensible conclusions, or whether interpretations from these products were simply cut and pasted into the expert’s own report without sufficient regard for their scientific foundation.

Complex Questions to Child Witnesses by Defense May Increase Conviction Rates

Eric G. Mart, Ph.D., ABPP  |  April 6, 2013

Preliminary research indicates that child witnesses produce more inaccurate responses when asked complex questions by defense attorneys. Although this has been thought by some to undermine jurors' perception of the reliability of statements made by child witnesses, beyond some preliminary studies there has been little research on the effect of complex questions directed to children in trials. However, a study entitled "Complex Questions Asked by Defense Lawyers But Not Prosecutors Predicts Convictions in Child Abuse Trials" was published in the June 2009 issue of Law and Human Behavior, which is the journal of the American Psychology-Law Society (the Forensic Psychology Division of the American Psychological Association) which provides important preliminary information about this issue.

The authors of this article, utilizing techniques derived from applied linguistics, analyzed the complexity of questions put to child witnesses drawn from felony child sexual abuse cases in Los Angeles County, California. Their analysis found that, on average, there were no significant differences between the number of words used by defense attorneys and prosecutors, nor was there a significant difference between the complexity of questions used by either group of attorneys. However, these researchers found that while the relative complexity of questions asked of children by prosecutors did not affect the outcome, the use of more complex questions by defense attorneys was associated with juries returning more guilty verdicts. Further, this trend was a powerful one, with the use of more complex questions by defense attorneys having been shown to be associated with double the rate of convictions of the defendant.

What is the explanation for this powerful relationship between the complexity of questions that defense attorneys ask child witnesses and increased conviction rates? It is not possible to know for sure from one study. The authors suggest two alternative theories: the first is that complex questions from defense attorneys that produce confusion or "I do not know" answers from children may be seen as unfair and increase juror empathy for the child. An alternative theory is that defense attorneys may be asking more complicated questions of child witnesses in situations where the prosecution has a stronger case. In either case, defense attorneys may wish to give serious consideration to how they structure questions asked of child witnesses in sexual assault cases and attempt to make the questions easy to understand and answer.


Evans AD, Lee K, Lyon TD. Complex questions asked by defense lawyers but not prosecutors predicts convictions in child abuse trials. Law Hum Behav. 2009 Jun;33(3):258-64.

Where Do Psychological Test Interpretations Come From?

Eric G. Mart, Ph.D., ABPP  |  March 30, 2013

Most reports authored by psychologists and some by psychiatrists contain descriptions of test results. Psychological tests are used in many types of forensic assessments; child custody, mental state at time of offense and criminal competencies are just a few examples. When it comes to tests of personality functioning, objective inventories such as the Minnesota Multiphasic Personality Inventory-2 (MMPI-2) the Personality Assessment Inventory (PAI) and the Millon Clinical Multiaxial Inventory are among the most commonly used, although many others are sometimes employed.

Lawyers deposing or cross-examining mental health experts should be aware that these tests can be scored in several ways. They can be hand scored, although this is becoming much less common. In most cases they are computer scored using proprietary software from the publisher of the test. Experts have the option to download a score report and interpret the scores themselves. They can download a narrative "canned" report that interprets the test for them. Some individuals choosing the latter option may actually cut and paste whole paragraphs of the narrative into their own report without attributing the source.

Most experienced forensic mental health experts avoid the narrative versions because they do not want to be locked into the interpretations and diagnoses provided by these reports. Another problem is that it is not always possible to know about the source of the interpretations or whether they are based on empirical studies, clinical lore or guesswork. Further, cutting and pasting such material directly into a report may constitute a copyright violation. Finally, some mental health experts are under the mistaken impression that if they don't print out the narrative, it is not part of their file and therefore not discoverable.

For these reasons, attorneys may find it useful to determine just how the tests employed by an expert were scored. Experts can also be asked directly if they have an interpretive report on their computer that they did not supply as part of discovery. If so, the report should be obtained, and the expert's report should be compared side by side with the "canned" report. The expert can also be questioned about their understanding of the scientific basis of the statements they included in their report. In many cases they will have no idea about the reliability of the interpretive statements upon which they relied.