Dr Jane Lonie, Clinical Neuropsychologist

Consideration of a client’s cognitive capacity for decision making extends beyond a conversation with a client to query the client’s conversational skill. Awareness of questions to ask and records to make to go beyond that surface-level assessment both safeguards the will and preference of a client and mitigates a range of risks for a provider of professional services.

Professionals in the fields of health, allied health, law and financial planning are among the many who need to know that while capacity is a legal construct, its underpinnings are cognitive.

Legal capacity is a construct, its underpinnings are cognitive

Faced with a client in a new case, matter or project, when the client’s capacity is in doubt the client is sometimes referred on for specialist medical opinion. In those situations the referrals usually seek information about whether the client’s cognitive abilities are intact or impaired.

In those situations typically the issue concerns the client’s legal capacity. A central question is: To what extent, do any cognitive impairments impact on the client’s capacity to execute the transaction or other proposed significant life, wealth or wellness decision to be made?

Any consequent consultation for the client should also involve asking whether and how it is needed or might be possible to support the client’s decision making capabilities in order to facilitate and maximise their capacity.(1)

Complicating understandings for determining legal capacity is different jargon or terminology used by lawyers, medical experts and other disciplines. These differences between disciplines on the topic of cognition in determining legal capacity is a lingua franca problem.(2)

Ability to converse vs higher-level or executive aspects of cognition

The enquiry to be made varies even within the discipline of law and its many branches.

For example, in criminal law, notions of conforming and controlling behaviour, appreciating wrong and the consequences of behaviour and premeditation are underpinned by cognitive constructs like inhibition, empathy and adaptability. In civil law, notions of understanding, appreciating, evaluating, ‘sound mind’ and lucid interval are underpinned by cognitive constructs like memory, attention or arousal, working memory, reasoning, future thinking, judgment and appraisal.

Professionals are reasonably good at recognising the less complex cognitive functions that impact on decision making and legal capacity, such as comprehension or communicating. They are generally considerably less good at recognising the higher-level aspects of cognitive function that impact on decision making capacity, including those cognitive functions outlined above.

This is problematic, in a practical sense, for three reasons.

  • First, understanding within the context of legal capacity is not considered synonymous with simple comprehension and is seen to encompass a range of what we refer to medically as higher-level or executive brain functions, some of which were mentioned above.(3 )
  • Second, cognitive impairments of this higher-level or executive nature are present prior to the point at which cognitive impairment or dementia is diagnosed or even recognised as being present among elderly clients.(4)
  • Thirdly, in the context of a legal practitioner, a contested will or enduring power of attorney or guardianship case centres on these higher-level or executive aspects of cognition, not on whether or not a client is able to communicate or understand.(5) These cognitive abilities are far more obvious for all to see, agree on, and to be alerted to so as to act with care and caution to serve a client’s best interests, will and preference.

Assume capacity, but don’t abdicate your responsibility

Capacity is to be assumed unless there is reason to suspect otherwise.(6) However, people in business and providers of professional services cannot abdicate responsibility for assessing capacity, leaving it to medical specialists, as the very process of deciding to seek out a specialist opinion requires some preliminary evaluation of a client’s capacity in and of itself.(7)

At what point, then, should the assumption of capacity be questioned or at least not assumed? If we assume capacity when dealing with clients aged 65, 80 and 90 years of age, we may be incorrect in doing so at rates of 1/10, 3/10 and 1/2 respectively. Helpfully, Justice Kunc has made some suggestions in the judgment of Ryan v Dalton; Re Estate of Ryan.(8)

If the assumption of capacity is to be based solely on a client’s ability to comprehend at a conversational level and to communicate, it follows that it will rarely be questioned. This being the case, be prepared to face the uncertainty that comes with determining who your client is, eg the cognitively impaired mother or her “helpful and supportive” son. Be prepared to address the risk that the service you provide may not be aligned with the will and preference of your client.


As an alternative to abdication, consider a client’s cognitive factors beyond those of surface-level conversation. Recognise the potential of even mild cognitive impairment to impact on a client’s decision making ability.

  • Consider the case of a client making a will. How might that client’s decision making process be impacted on by any inability to recall and retain relevant facts, information and advice, or indeed to hold the relevant facts and advice in mind for long enough to reason through and evaluate a range of options?
  • If your client is unable to appraise their own situation as a result of a loss of insight into their own cognitive illness or loss, or if they no longer have the cognitive ability to consider future consequences, how might this affect the client’s instructions given or decisions made?
  • How, if at all, would any loss of ability to read and to question the underlying intent and motives of others impact on their testamentary decision-making?

The integrity of these higher-level aspects of decision making must be verified to establish that it is “safe to proceed” from the perspective of a client’s decision making capacity.


  1. UN General Assembly, Convention on the Rights of Persons with Disabilities: Resolution adopted by the General Assembly, 24 January 2007, A/RES/61/106, available at bit.ly/2ZLyCtU (accessed 22 March 2019)
  2. J. W. Buckholtz and D. L. Faigman, ‘Promises, Promises for Neuroscience and Law’, Current Biology, 24:18 (2014), PR861-R867
  3. K. I. Shulman, S. G. Himel, I. M. Hull, C. Peisah, S. Amodeo and C. Barnes, ‘Banks v Goodfellow (1870): Time to update the test for testamentary capacity’, Canadian Bar Review, 95:1 (2017), pp.251–267
  4. Harrington et al, ‘Executive Function Changes Before Memory in Preclinical Alzheimer’s Pathology: A prospective, cross-sectional, case control study’, PLoS One 8(11): e79378 (2013)
  5. J. A. Lonie and K. Purser, ‘Assessing Testamentary Capacity from the Medical Perspective’, Australian Bar Review, 44:297 (2017)
  6. bit.ly/2LdoJSq
  7. bit.ly/2Jciiwr
  8. [2017] NSWSC 1007 (31 July 2017) [68]