INTRODUCTION

2.1 This chapter considers definitions of intellectual disability, in particular those definitions found in legislation (“statutory definitions”). Consistency and clarity in the terminology and definitions relating to intellectual disability are vital to avoid injustices, particularly if special procedures flow from a person’s diagnosis. At present there is considerable confusion in this area, often as a result of the variety of terms used to refer to intellectual disability. People with an intellectual disability are sometimes referred to as “mentally retarded”, “mentally handicapped”, “sub-normal” or “defective”, terms which are often now rejected as carrying pejorative connotations. In the Issues Paper the Commission noted that terms which use the word “mental” have been described as having “an inaccurate association with mental illness. These terms emphasise abnormality, pathology or disease, and tend to promote ideas of disability as being a sub-human condition”.¹ Submissions to the Commission have constantly stressed the need for a clear distinction between mental illness and intellectual disability. The continuing confusion between the two is exacerbated by the terms used in criminal law. For example the defence of “not guilty on the grounds of mental illness” (also known as the insanity defence) can apply to people with an intellectual disability (see Chapter 10).

2.2 The Commission believes “intellectual disability” to be the appropriate term for the purposes of this reference, and for legislation in New South Wales. It has already been adopted in Commonwealth and Victorian Crimes Acts and most submissions to the Commission have accepted the use of this term.² Though “developmental disability” is sometimes also used (see para 2.5), the Commission believes one term should be used consistently to avoid confusion. The Commission prefers the more precise “intellectual disability”, particularly in the criminal law context.

2.3 Apart from the confusion caused by different names, there are also differences of opinion about who should be considered to have an “intellectual disability”, leading to calls for a clear and recognised definition. By its terms of reference the Commission was asked to consider whether there should be a new and uniform statutory definition of “intellectual disability”. “Intellectual disability” and related terms have been defined in a variety of ways, in criminal, health and social service contexts. Appendix A sets out, by way of comparison, some of the definitions used in Australia and the United Kingdom. Many statutes contain outdated or inaccurate terminology and definitions, or use terms without definitions. Some submissions to the Commission³ have called for the removal of existing archaic, derogatory, ambiguous or inaccurate definitions from the statute book, a process which is already occurring. The Commission agrees with this approach. The more difficult decisions are what definition (if any) of intellectual disability should be used in legislation, and whether the disadvantages of having a definition outweigh its advantages. Before attempting to assess the merits or otherwise of a statutory definition of “intellectual disability”, the existing definitions must first be considered.

WHAT IS INTELLECTUAL DISABILITY?

2.4 People with an intellectual disability have significantly lower than average intellectual ability and deficits in social and adaptive functioning, that is, limitations in such areas as communication, social, daily living or movement skills. The implications of an intellectual disability for daily living have been described as follows:

People with intellectual disabilities have the same sorts of needs, goals, dreams, hopes and aspirations as the rest of the population, as well as the same range of emotions. Because of their disability they may display limitations in learning, speech, self care, movement, independent living, employment and relationships. Many people need to use the same environment and consistent instructions when learning new skills such as shopping or cooking. Support may be needed to reduce the restrictions that disability might otherwise impose on life. For example, a person with an intellectual disability may have trouble reading the paper in order to find out what jobs are advertised; longer time may be needed to complete a task, such as filling out a form; frequent reminders may be necessary to ensure medication is taken regularly.⁴

2.5 The cause of a person’s intellectual disability is not known in most cases. Some identifiable causes include: hereditary factors; chromosome abnormalities, such as in Down Syndrome; brain damage before or at birth; brain damage after birth due to illness or accident; malnutrition or other deprivation in early childhood.⁵ The term “developmental disability” is sometimes used as a synonym for “intellectual disability”, but it is generally considered to be a broader term than intellectual disability,⁶ in that it can include a number of other disabilities (such as cerebral palsy) which arise during the “developmental” period (usually defined as the period up to 18 years of age) but which may be of a physical, rather than an intellectual, nature. Furthermore, some developmental disabilities may be overcome with or without treatment or management and may not be permanent. It is important to recognise that an intellectual disability is not a mental illness or a physical sickness which can be “cured”,⁷ though people with an intellectual disability can benefit from appropriate educational programs.⁸ Nor is an intellectual disability necessarily accompanied by a physical disability or obvious from a person’s appearance.

2.6 The severity and consequences of an intellectual disability will vary from person to person and “generalisations about the needs of people with an intellectual disability .. must be treated with caution.”⁹ Any definition needs to take this diversity into account. A person’s intellectual disability can be classified as “mild”, “moderate”, “severe” or “profound”, based upon certain IQ (intelligence quotient) ranges.¹⁰ A further category, “borderline”, is also used to indicate people just above the mild range in terms of intellectual functioning.¹¹ A person with a “severe” or “profound” disability may be unable to learn basic social skills such as speech, walking and personal care, and is likely to require supported accommodation. The majority of people with an intellectual disability have a “mild” level of intellectual disability and “can learn skills of reading, writing, numeracy, and daily living sufficient to enable them to live independently in the community.”¹² These classifications have limited utility and can sometimes be misleading. For example, such terms may suggest to criminal justice personnel, who do not have a full understanding of the disability involved, that a “mild” intellectual disability is inconsequential.¹³ Whether these categories should be included in statutory definitions is discussed at paras 2.29-2.30.

CLINICAL DEFINITIONS OF INTELLECTUAL DISABILITY

2.7 Three commonly-used clinical definitions of intellectual disability are proposed by the World Health Organisation (“WHO”),¹⁴ the American Psychiatric Association (“DSM III-R”),¹⁵ and the American Association on Mental Retardation (“AAMR”).¹⁶ Intellectual disability, or mental retardation as it is often known, as defined by these organisations, refers to:

a condition of arrested or incomplete development of the mind, which is especially characterised by impairment of skills manifested during the developmental period, which contribute to the overall level of intelligence, ie cognitive, language, motor and social abilities.¹⁷ [WHO, 1992]

significantly subaverage general intellectual functioning, accompanied by significant deficits or impairments in adaptive functioning, with onset before the age of 18.¹⁸ [DSM III-R, 1987]

substantial limitations in present functioning. It is characterised by significantly subaverage intellectual functioning, existing concurrently with related limitations in two or more of the following applicable adaptive skill areas: communication, self-care, home living, social skills, community use, self-direction, health and safety, functional academics, leisure, and work. Mental retardation manifests before age 18.¹⁹ [AAMR, 1992]

2.8 These definitions were not designed for the criminal justice system. For example, the main focus of the AAMR definition is the provision of appropriate services, which is a different issue from concerns about criminal responsibility and vulnerability which affect the criminal justice system. The National Council on Intellectual Disability has commented that the WHO system, often used by non-disability agencies such as the Department of Social Security and the Australian Bureau of Statistics, “tends to be rather confusing and over-complicates the issue for most useful purposes”. It prefers the AAMR definition, though recognising that:

it limits people with an intellectual disability to occurrence during the developmental stage (0-18 yrs). If this feature is ignored it most likely provides the most useful definition for criminal justice purposes because it highlights the combination of “IQ” and actual functioning.²⁰

The Commission accepts that a legal definition of intellectual disability will not be identical to a clinical definition, but it believes that the legal definition should not contradict clinical understanding, as this will not only cause problems for the expert witness but will add to the existing confusion in the criminal justice system about intellectual disability.

STATUTORY DEFINITIONS OF INTELLECTUAL DISABILITY

2.9 A person’s intellectual disability may be referred to in criminal legislation in a number of areas including:

• provisions affecting an accused’s fitness to be tried or criminal responsibility (see Chapters 4, 5 and 10);
• specific sexual offences involving people with an intellectual disability (see Chapter 9);
• procedures for giving evidence (see Chapter 7); and
• sentencing provisions (see Chapter 11).
  
  

New South Wales statutory definitions

2.10 Although s 66F of the Crimes Act 1900 (NSW) does contain a definition of intellectual disability, the definition is applicable to that section only. There is no general definition which can be applied consistently across all New South Wales criminal legislation.

Crimes Act 1900 (NSW)

2.11 Section 66F of the Crimes Act 1900 (NSW) creates a number of sexual offences against people with an intellectual disability. Intellectual disability is defined for the purpose of that section only as:

an appreciably below average general intellectual function that results in the person requiring supervision or social habilitation in connection with daily life activities. [s 66F(1)]

This definition does not apply to the other (aggravated) sexual offences discussed below. It has been criticised for being inconsistent with the term “intellectual disability” as understood by psychologists, and as inappropriate having regard to the policy objectives of legislation affecting people with an intellectual disability.²¹ The requirement of supervision or “social habilitation” (that is, the gaining of social capacity or skills) appears to indicate a higher level of disability than that experienced by the majority of people with an intellectual disability.

2.12 Since its introduction in 1987, the section has been rarely used.²² As there are so few cases in this area, it is difficult to know how such a definition will be interpreted by the courts, for example, whether people with a mild intellectual disability will be included. Some guidance on this issue may be found in the comments of the then Premier, the Hon Barry Unsworth MP, when introducing the amendments into Parliament:

[i]ntellectual disability is carefully defined to attract the protections afforded by the legislation to those people whose level of disability requires such protection ... The intent of these reforms is to provide protection from sexual exploitation and assault to people with a significant intellectual disability.²³ [emphasis added]

Other difficulties with the section and the aggravated sexual offences, apart from definitional ones, are discussed in Chapter 9.

2.13 As well as the sexual offences created by s 66F, the Crimes Act 1900 (NSW) contains provisions for harsher sentences for other sexual offences where there are “circumstances of aggravation”.²⁴ One of these circumstances is stated to be a “serious intellectual disability” of the victim. “Serious intellectual disability” is not defined. According to the Second Reading Speech of the then Attorney General, Mr John Dowd QC MP, the term was not defined, as “[t]his is a matter for the courts.”²⁵ It is unclear, however, what level of intellectual disability is considered to be “serious”, when the usual terms employed to differentiate levels of disability are “borderline”, “mild”, “moderate”, “severe” and “profound”. The Attorney General’s Committee stated that either amending the sections to replace “serious” with a more meaningful term or defining the word “serious” in this context should be considered.²⁶ The New South Wales Sexual Assault Committee called for the removal of the reference to “serious” intellectual disability as this term was not used professionally.²⁷ The New South Wales Council for Intellectual Disability (“CID”) suggested that the phrase “serious intellectual disability”:

should not be replaced with “moderate” or even “severe or profound” but rather the provision [should be] rephrased to state the objects of the provision, and detail more precisely the particular matters which may exist for the victim with a disability which make an assault against such a person more grievous.²⁸

2.14 The Crimes Act 1900 (NSW), in s 23A(1), also provides for a defence to murder known as “diminished responsibility”. The defence states that a person shall not be convicted of murder if he or she was suffering from:

such abnormality of mind (whether arising from a condition of arrested or retarded development of mind or any inherent causes or induced by disease or injury) as substantially impaired his [or her] mental responsibility for the acts or omissions ... [emphasis added]

The Commission believes that “arrested or retarded development of mind” clearly encompasses an intellectual disability. Whether people with an intellectual disability will satisfy the test for diminished responsibility, however, will depend upon the nature or severity of their disability. The operation of the defence has caused some controversy, resulting in a separate New South Wales Law Reform Commission inquiry into this defence.²⁹

2.15 The Crimes Act 1900 (NSW) also refers to “appreciably below average general intellectual function” in Part 15A, which deals with Apprehended Violence Orders (“AVOs”). In that Part, if the court is of the opinion that the person seeking an AVO “is suffering from an appreciably below average general intellectual function” the court does not need to be satisfied that the person “in fact fears that [a personal violence] offence will be committed, or that such conduct will be engaged in”. The Commission seeks submissions whether this phrase should be left undefined, or whether the term “intellectual disability” should be substituted.

Mental Health (Criminal Procedure) Act 1990 (NSW)

2.16 The Mental Health (Criminal Procedure) Act 1990 (NSW) refers, in s 32, to defendants who are “developmentally disabled”. This section gives a Magistrate the discretion to dismiss (often on conditions) the charges against such defendants brought before the Local Courts. “Developmentally disabled” is not defined, although, as discussed above, it is usually taken to refer to a wider group than “intellectually disabled”. The absence of definition is surprising, considering the scope of this section. Submissions to the Commission have referred to the absence of a definition of “developmental disability”³⁰ and the resulting variation in the use of the section. Other concerns relating to s 32, apart from the definitional question, are discussed in Chapter 5.

Victorian statutory definitions

2.17 In Victoria the statutory definition of “intellectual disability” is “significant sub-average general intellectual functioning existing concurrently with deficits in adaptive behaviour and manifested during the developmental period”.³¹ It may be illuminating to consider how that definition has been interpreted. According to the Victorian Intellectual Disability Review Panel (the “Review Panel”), in relation to “intellectual functioning”:

• only a standardised test using standardised procedures may be admitted as evidence of IQ and that a single cut-off point of the full scale IQ (eg IQ=70) may not be used to determine eligibility,
• “significant sub-average general intellectual functioning” as defined by the Act, is interpreted by the Review Panel to mean “two standard deviations below the mean plus or minus the standard error of measurement” of the particular test, at the 95% level of confidence. Rather than the single cut-off point, an upper limit for inclusion should be expressed in the form of a range around the standard error of measurement: in the case of WAIS-R this means a range of the full scale IQ 65 to 75. Persons whose IQ is within this range and below are considered to have satisfied this criteria,
• in practice IQ 75 becomes a maximum level of the range for inclusion as eligible for services consistent with the definition of the Act and internationally accepted standards,
• that the psychometric test used for measuring intellectual functioning must measure ‘general’ intellectual functioning and not just the person’s deficits or strengths.³²

2.18 In relation to “deficits in adaptive behaviour” the Review Panel commented:

• subjective judgements of adaptive behaviour are inadequate,
• methods of assessment of adaptive behaviour which do not have total scores and normative data, are also not relevant,
• the Review Panel would only accept at this stage assessments of adaptive behaviour which used the Vineland Adaptive Behavior Scale,
• that deficits in adaptive behaviour should be given greater weight at the borderline levels of intellectual functioning in determining eligibility.33

2.19 The Review Panel has also expressed some concerns for the people who are excluded from this definition, for example: former Community Services clients who no longer fit within the current definition, some people with autism, people with “dual disability” or behavioural disturbances and people with a “borderline” IQ level. In relation to people with a borderline intellectual disability the Review Panel commented that:

[t]his group of people may also have significant deficits in adaptive behaviour, severe behavioural problems and appear to be at great risk. They are more likely to be involved in the criminal justice system or at risk as victims because of their inability to adequately deal with their circumstances, their family, social and sexual relationships, employment etc.³⁴

The inclusion of people with a “borderline” IQ level in definitions of intellectual disability remains controversial.

Is a statutory definition desirable?

2.20 It has been argued that a new and uniform statutory definition of “intellectual disability” would remove the present confusion caused by existing imprecise or conflicting statutory definitions. Some submissions have supported a statutory definition of intellectual disability, though this support is often qualified and contains suggested limitations on the scope of the definition.³⁵ Others have stated that they do not think that there should be a statutory definition as it would be clinically inaccurate.³⁶ It could also be stigmatising, increasing the “labelling” of people with an intellectual disability. Many people do not wish to be identified as having an intellectual disability and fear that, with such a label, they may receive worse, not better, treatment within the criminal justice system. The Law Society of New South Wales, however, stated that it:

does not believe that the disadvantages of having a definition outweigh the advantages. While the definition may exclude certain people whose intellectual disability might be the subject of heated debate between psychologists, psychiatrists and social workers, the advantage of certainty may well make it easier to reach a greater consensus of opinion as to a person’s intellectual disability and save a person from much unnecessary stress and trauma with professionals arguing in a clinical way about a person’s mental capabilities.³⁷

2.21 A further advantage was suggested by the Legal Aid Commission of NSW:

it would assist the courts, legal practitioners, police and others involved in the criminal justice system by making them aware of the nature of those disabilities. This in turn could assist the person with the intellectual disability by giving some proper recognition to those disabilities, which might otherwise be overlooked or glossed over.³⁸

Similar comments were made by Redfern Legal Centre Intellectual Disability Rights Service (“IDRS”)³⁹ and CID, which thought that such a definition was important to ensure that all personnel within the criminal justice system share a common understanding, and would have “considerable educative value”.⁴⁰ Reservations expressed have included the problems caused by applying definitions too strictly and the difficulty of developing a definition which could cover the varied levels of intellectual disability.⁴¹ The Legal Aid Commission of NSW also was concerned that a uniform definition “may include persons to whom the legislation was never meant to apply, or conversely exclude them.”⁴² It therefore advised the Commission that although, on balance, it supported the development of a consistent definition, the best approach may be to create an “operational” definition and then specify clearly when it should be applied.

2.22 The Commission recognises that statutory definitions of intellectual disability already exist and believes they can serve a useful purpose, if accurate and appropriate, in providing greater certainty in the operation of the law. The Commission believes that, as far as possible, within the criminal law context the same definition should be used to avoid confusion.

Should the same definition apply in criminal and social welfare contexts?

2.23 It has been suggested to the Commission that, to avoid confusion, a new definition should apply not only to the Crimes Act 1900 (NSW) and the Mental Health (Criminal Procedure) Act 1990 (NSW) but also to the Mental Health Act 1990 (NSW) and relevant community or welfare legislation.⁴³ In Victoria, for example, the definition of intellectual disability in the Crimes Act 1958 (Vic) adopts the definition in the Intellectually Disabled Persons’ Services Act 1986 (Vic). In the Issues Paper the Commission noted that non-criminal statutes affecting people with an intellectual disability fall outside the terms of the Commission’s reference. As well, despite the obvious advantages of uniformity in both criminal and “welfare” legislation, and the danger of criminal lawyers and service providers using different definitions of “intellectual disability”, the Commission believes the two systems are inherently different in aims and context. For example, the welfare model usually favours a broad definition so as not to deny people services, whereas definitions in a criminal law context need to be as unambiguous as possible, bearing in mind the consequences involved. It must also be acknowledged that many of the definitions set out in legislation (see Appendix A) were drafted to fulfil specific purposes of the Acts in which they appear. They are thus not always easily extended beyond the parameters of a particular piece of legislation.

What should a statutory definition contain?

2.24 Once it has been accepted that there should be a standard statutory definition of intellectual disability in criminal legislation, the more difficult question is the content of that definition. Submissions have varied on the issue of how broad or narrow a definition should be. A narrow definition may exclude some groups of people; for example, the definition which limits intellectual disability to a condition arising in the “developmental period” will not apply to those who are brain damaged as a result of an accident or injury in adulthood. An overly technical definition may also be incomprehensible to lawyers and the general community. The Law Society of New South Wales favoured the development of a definition of intellectual disability “in as wide and broad terms as possible without losing the sense and meaning after suitable consultation with specialists in the field.”⁴⁴

2.25 Other submissions have also suggested a definition in broad terms, such as “handicapped/impaired to function in society as the result of a disability”. These definitions focus on how the intellectual disability affects social functioning.⁴⁵ Such a vague definition is probably unworkable in the context of a criminal trial. An alternative is a definition that includes a “checklist” or series of categories, including whether the person can read, whether they can undertake basic tasks of daily self maintenance etc.⁴⁶ Developing an acceptable checklist would be both difficult and costly, and may be either over-inclusive or under-inclusive. No checklist could be comprehensive and allow for different cultures or family backgrounds. Any definition based on what are effectively adaptive skills would not necessarily indicate the presence of intellectual disability as people may have poor adaptive skills for a variety of reasons, for instance mental illness.

Reference to IQ scores and categories of disability

2.26 The question remains: which aspects of the definitions referred to above should be included in legislation. For example, is it appropriate to include references to IQ-based categories of intellectual disability? Definitions based solely on IQ levels have been criticised, but definitions without an independent standard may prove unworkable. According to Hayes and Craddock:

[r]eliance upon IQ scores alone in classification of intellectually disabled people is condemned on many grounds, principally - that IQ scores do not reflect social or adaptive skills, that the tests are not fair to persons from differing cultural backgrounds, that the categories are arbitrary and an individual’s IQ may change, for example, decrease as a result of environmental deprivation, or increase owing to special education programmes, and that the categorisation is of little value in predicting an individual’s long-term adjustment or abilities.⁴⁷ [emphasis added]

Similarly, according to Noble and Conley:

Reliance on rigid IQ criteria to determine whether an offender is entitled to special consideration may lead not only to inequities among people who differ only slightly in mental competency but also to inappropriate sentencing and rehabilitation decisions. This is because the ability to distinguish right from wrong, to be competent to stand trial, to plead guilty, to be a witness, or to participate meaningfully in rehabilitation programs depends on many factors, among which level of intelligence is only one.⁴⁸

2.27 By contrast, one submission from a clinical psychologist has argued that a clinical definition based on IQ is the most valid and reliable available.⁴⁹ IDRS has stated that a definition should “include some concept of a lower capacity for intellectual functioning, as well as reference to social or habilitation skills”, and that “[t]he disability community would reject any definition which only considered an ‘IQ’, or similar score or ranking.”⁵⁰ CID stated that definitions should include both “significantly below average intellectual functioning and marked impairment in social and habilitation skills relative to both biological age and to the social culture.”⁵¹

2.28 The establishment of an arbitrary cut off point (such as IQ of 70) for intellectual disability is also controversial. Associate Professor Susan Hayes has stated that it is inappropriate to set an IQ cut-off for intellectual disability because accepted definitions include both IQ and adaptive skills.⁵² Clearly there are likely to be injustices caused by a rigid IQ cut off.⁵³ The Commission does not believe that its proposed definition should include references to IQ scores. To do so would require a reference to specified tests and confidence levels, as there can be considerable variation in IQ scores, even at a 99% confidence level. The Commission believes that what comprises “significant deficits in intellectual functioning” can be left to the professional judgment of expert witnesses such as psychologists, and that no IQ “cap” should be set in a statutory definition.

2.29 As discussed at para 2.6, the usefulness of the categories of intellectual disability (“mild”, “moderate”, “severe” or “profound”) has also been questioned. Some organisations are opposed to the use of a definition which draws a distinction between different levels of disability, as “[t]hese classifications would once more place emphasis on detailing the disability, rather than on its relevance to the legal issue in point.”⁵⁴ The Illawarra Area Consultative Committee expressed concern at the categorisation of people with an intellectual disability into levels of disability rather than individual assessment “if different strategies/protocols are utilised when dealing with different levels”, because of the variety of abilities found within each level.⁵⁵ For example, over three-quarters of people with an intellectual disability are classified as having a “mild” level of intellectual disability, and therefore an enormous range of abilities will be found in this category.

2.30 A legislative formulation must overcome, however, the problems created by these categories, which at least have the advantage of being generally accepted by experts. The Commission is not persuaded that any alternatives for these categories would be suitable for inclusion in a statutory definition, for example the AAMR’s use of references to “pervasive” or “intermittent” needs for “habilitation” and support⁵⁶ are unlikely to be helpful in a criminal court. These categories or comparisons may, however, be useful for other purposes. By way of illustration, comparisons based upon percentile ranking of the population (for instance, “the accused has been assessed as having an IQ of 70, which means that approximately 97% of the population are functioning intellectually at a higher level”) may assist a judge or jury to understand the severity of the disability compared to the general population. Comparisons based upon “mental age”, such as references to a person having a “functional age of 6 years” should be treated with caution, however, as they are based on:

an assumption that such a person may also have the maturity, experience and emotional development of a person of the so-called “mental age”, which may or may not be so.⁵⁷

One possibility is that, for the purposes of the criminal justice system, expert witnesses develop a duplicate set of categories (for instance, borderline = Level 1, mild = Level 2, moderate = Level 3 etc). Though such categories should not be a substitute for individual-based assessment, and the wide variety of abilities within each of these categories should not be overlooked, at least it could overcome the confusion which appears clearly to exist in the criminal justice system about the significance of a “mild” intellectual disability. Such a proposal would be more appropriately considered by the relevant psychological and psychiatric associations, rather than a matter for legislation, and the Commission seeks submissions from these bodies.

Distinction between intellectual disability and brain injury

2.31 As outlined above, most clinical definitions of intellectual disability only include people who have a disability which arises before the age of 18 years, and thus do not encompass adults who receive an injury to the brain. Such brain injuries may arise from industrial or motor vehicle accidents,⁵⁸ near drowning, drug and alcohol abuse, abuse of other chemicals (for example, glue sniffing) or serious illness. The brain damage may lead to intellectual and adaptive deficits such that the person would be classified by a psychologist as having an intellectual disability. According to Associate Professor Susan Hayes the usual terminology is “acquired brain damage resulting in intellectual disability/cognitive deficits and social and adaptive skills deficits” or “intellectual disability subsequent to a brain injury”.

2.32 Organisations who represent the interests of people with the conditions variously known as “brain damage”, “head injury” “traumatic brain injury” or “acquired brain injury”,⁵⁹ however, are keen to stress the difference between a “developmental” intellectual disability and an “acquired” disability and state that the latter group generally do not wish to be considered as “intellectually disabled”:

[a]dults with an acquired brain injury have usually had what could be termed a normal social and intellectual development. ... Their self identity and expectations of life after an injury are still strongly shaped by their social and intellectual development before the brain injury. ... The person who has a brain injury will have aspects of their self identity, behaviours and expectations based on pre-injury experience interspersed with their acquired disability(ies).⁶⁰

Different services and support may therefore be necessary. The question remains whether the difference between the two conditions is material for criminal justice purposes, as people suffering a brain injury may, as with intellectual disability, experience permanent restrictions to their physical and cognitive abilities, with behavioural or personality implications. They may then encounter problems in remembering details, concentrating, comprehending complex ideas, planning or organising, and processing information quickly. The personality changes may affect their sense of drive or motivation, self control, emotional state, degree of personal insight and perceptions of relationships with others.⁶¹ These possible consequences of brain injury may have implications for the person’s fitness to be tried, available criminal defences, appropriate sentencing options and custodial or non-custodial “rehabilitation” programs. Submissions to the Commission have reported similar difficulties for people with a brain injury in the criminal justice system as those experienced by people with an intellectual disability, for example, the lack of identification or understanding of the person’s disability at the police station,⁶² and suggestibility and unreliability in providing information.⁶³

2.33 It may be impossible to determine the cause of a person’s disability, or when it arose, even with a detailed medical history. For some people involved in the criminal justice system there is no evidence to indicate whether the disability arose in the developmental period or not, as they were not assessed psychometrically during the developmental period, nor were they known to any disability agencies. Apart from the difficulty of determining the cause of a person’s disability, the disadvantage of drawing a distinction between an intellectual disability acquired in the developmental period and one acquired after the age of 18 is that people in the latter group may be disadvantaged in their contact with the criminal justice system, if protections and procedures available to people with an intellectual disability are not extended to them in appropriate cases. It has been commented that:

[r]egardless of whether the event (eg, accident, substance abuse) causing mental limitations happened before or after age 18, criminal justice system officials must confront the same problems of social adaptation and offer the same kinds of services to assist the affected individuals to respond appropriately to the due process requirements of the criminal justice system and, if found guilty and sentenced to prison, to help them adjust to prison life and prepare for subsequent release.⁶⁴

It has therefore been suggested that because accused people with brain injuries (which have affected their cognitive capacities) report similar difficulties in the criminal justice system to those who have a “developmental” intellectual disability, the manner in which they are properly regarded in the system may in many instances be considered together. For instance, perhaps the same legislative diversion provisions should have equal application to either group.

2.34 The distinction between brain injury and intellectual disability is a very difficult and controversial area. The Commission does not consider it appropriate to exclude from consideration people who have an intellectual disability merely because their disability arose after the age of 18 years or because it is not known when or how their disability arose. The person’s disability is relevant at the time of the alleged crime and at all subsequent times in their progress through the criminal justice system. In most cases, when and how that disability arose is irrelevant. It seems that a person who receives brain damage from a car accident at the age of 17 could, on most current definitions, be classified as having an intellectual disability, whereas if the same accident occurred when the person was 18, that person would be considered to have an acquired brain injury. Nevertheless, the Commission does not wish to recommend a definition of intellectual disability which is confusing, inappropriate or not accepted by professionals giving expert evidence in this area. There may also be ways in which the distinction between a “developmental” intellectual disability and an “acquired” intellectual disability does have consequences for the criminal justice system, and the Commission seeks submissions in this regard.

2.35 As discussed, most clinical definitions describe intellectual disability as significantly below average general intellectual functioning existing concurrently with deficits in adaptive behaviour, manifested before the age of 18 years. The Commission has considered a number of possible options for incorporating the difficulties discussed above in definitions of intellectual disability contained in criminal legislation.

2.36 Option 1: Retain the distinction between a developmental and an acquired intellectual disability. Intellectual disability would be defined in similar terms to the clinical definitions. Criminal legislation in other jurisdictions (for example Victoria) uses such a “developmental” definition for intellectual disability. A reference to “two or more adaptive deficits” rather than “adaptive deficits” would avoid any arguments about exactly how many adaptive deficits are required. A limited definition will, however, exclude people whose intellectual abilities are clearly relevant for the criminal justice system in a similar way to intellectual disability, for example, brain injuries and dementia, including Alzheimers disease. It seems logical that other disabilities which affect cognitive functioning should receive the same protections or consideration as intellectual disability, as in the criminal justice system the cause of the disability is largely irrelevant; it is the impact of the disability which matters.

2.37 Option 2: Remove the requirement that the intellectual disability arose during the developmental period. Without that limitation, people with a relevant brain injury (those with significant intellectual and behaviour deficits as a result of the injury), or those for whom it is unclear when the disability arose, would fall within the definition of intellectual disability. This was suggested by the National Council for Intellectual Disability, see para 2.8. Such a definition could, however, include conditions such as dementia, which may be inappropriate and confusing, particularly if this definition is to serve an educative function and to be used wherever possible in future legislation.

2.38 Option 3: Intellectual disability is deemed to include brain injury. A possible compromise approach would be to retain a developmental definition of intellectual disability but state that, for the purposes of the relevant Act, any definition of intellectual disability shall be deemed to include a reference to a brain injury or damage which affects intellectual functioning. This effectively turns intellectual disability into an umbrella term, and there could be arguments about what conditions should or should not be deemed to be included, for example, it seems illogical to include brain injury but not dementia.

2.39 Option 4: An umbrella term. Another way of retaining the distinction between different disabilities, while ensuring that all relevant people receive the safeguards deemed appropriate for people with some form of impaired intellectual functioning, however caused, is to develop an “umbrella term” to cover the various forms of cognitive disability, including intellectual disability, brain injury, or dementia, but not mental illness. The umbrella term (for instance “mental impairment”, “cognitive disability”, “impaired intellectual functioning” or “mental condition”) could then be conveniently used for legislative provisions designed to cover a variety of conditions. This approach was adopted by the Victorian Law Reform Commission, while acknowledging its limitations.⁶⁵ It is difficult to find, however, both an appropriate umbrella term and acceptable definitions for each of the conditions covered by that term. “Mental impairment” has been used as an umbrella term in a number of contexts (for example in the Model Criminal Code prepared by the Criminal Law Officers Committee of the Standing Committee of Attorneys-General⁶⁶ and by the Victorian Law Reform Commission) but usually includes mental illness as well as cognitive disabilities. “Mental condition” has been defined in s 3 of the Mental Health (Criminal Procedure) Act 1990 (NSW) to refer to “a condition of disability of mind not including either mental illness or developmental disability of mind”. Therefore the difficulty with using “mental condition”, apart from the possible inappropriate confusion with mental illness (see para 2.1), is the need for consistency of usage between the Crimes Act 1900 (NSW) and the Mental Health (Criminal Procedure) Act 1990 (NSW). “Mental condition” is also used, without definition, in a broader sense in s 556A of the Crimes Act 1900 (NSW) and in s 19 of the Children (Detention Centres) Act 1987 (NSW). Furthermore, in common usage it is often used neutrally, without an implication of impairment. The Commission therefore believes that “mental condition” would be an inappropriate and confusing umbrella term. It prefers a term which gives an insight into the nature of the condition involved, such as “impaired intellectual functioning”.

2.40 The Commission currently prefers the fourth option. Option 4 retains a recognised definition of intellectual disability, whilst providing for the possibility of including in future legislative provisions other people whose intellectual deficit (however caused) is of such significance that it affects their treatment in the criminal justice system.⁶⁷

CONCLUSIONS

2.41 Submissions have generally supported the introduction of an appropriate definition of intellectual disability in criminal legislation. The Commission believes there is merit in proposing a new statutory definition of intellectual disability for the relevant New South Wales criminal statutes in this area, the Crimes Act 1900 and the Mental Health (Criminal Procedure) Act 1990, and to make consequential amendments to the Mental Health Act 1990. The Commission’s provisional proposals to this end are set out below. The Commission is presently of the view that, in the interests of consistency, this definition should be considered for inclusion in other legislation, except where this may be inappropriate for the objects of the legislation, such as in the area of service provision, where a broad definition in lay person’s terms may be considered more appropriate. The proposed definition is similar to the clinical definitions referred to in paras 2.7-2.8 and to the definitions of “intellectual disability” used in Victorian legislation. Though the definition uses technical terms such as “adaptive behaviour”, the Commission has been unable, at this stage, to devise a sufficiently accurate definition without these terms, which are clearly understood by professionals. The Commission believes that in the context of a criminal trial it is inappropriate to have a vague or possibly over-inclusive definition. It seeks submissions, however, about whether it has achieved the right balance in its proposals and about any preferable alternatives. It particularly seeks submissions from people who give expert evidence in this area, such as psychologists and psychiatrists.

2.42 If the Commission’s proposals are implemented, the new definition would only affect the interpretation of the sexual offences found in the Crimes Act 1900 (NSW) (paras 2.11-2.13) and the diversionary procedure set out in s 32 of the Mental Health (Criminal Procedure) Act 1990 (NSW), as they are currently the only instances of criminal legislation specifically referring to intellectual disability. If the term “intellectual disability” is used in any future amendments to these Acts, the same definition would presumably apply. The Commission also suggests that, if the exposure draft of the Evidence Bill 1993 (NSW) becomes law, that the same definition be included in that Act. The clauses in that Bill which refer to intellectual disability are discussed in Chapters 7 and 8.

2.43 The Commission recognises the concern that people whose disability did not arise before the age of 18 years (or where the cause of the disability is unknown) may be inappropriately excluded from the procedures or recognition afforded to people with an intellectual disability. The Commission therefore also proposes that an umbrella term, “impaired intellectual functioning”, be introduced into the Acts listed below to cover all conditions which impair a person’s intellectual functioning (but not including mental illness). This term could be used by legislators in preference to “intellectual disability” wherever a policy decision is made that a provision in one of the listed Acts should apply to all people with such an impairment, however that condition arises, including intellectual disability, brain injury or dementia. The rest of this Discussion Paper, however, generally refers to people with an intellectual disability, except in Chapter 4 (fitness) Chapter 5 (diversionary procedures) and Chapter 10 (the defence of mental illness), where a broader group of people are already affected by the relevant provisions. The Commission’s terms of reference refer to people with an intellectual disability, and the Commission has accordingly limited its research to this area, except where there are existing areas of overlap with other groups. From the limited information received to date it seems illogical to limit many of the proposals to people with an intellectual disability and not to extend them to other people with impaired intellectual functioning. There may, however, be other factors which suggest that some of the proposals in this Discussion Paper should not be extended in this way. At this stage the Commission invites submissions about which of the proposals should be extended to those other groups, or alternatively why the proposals should remain limited at the Report stage to people with an intellectual disability, as defined in this Paper.

1. That a new statutory definition of intellectual disability be introduced as set out below.

(a) That the Crimes Act 1900 (NSW), the Mental Health Act 1990 (NSW), the Mental Health (Criminal Procedure) Act 1990 (NSW) and the Evidence Bill 1993 (NSW) (the “listed Acts”) be amended to include the following definition:

“Intellectual disability” in relation to a person means a significantly below average general intellectual functioning existing concurrently with two or more deficits in adaptive behaviour, and which has manifested before the age of 18 years.

It is important that this definition remain uniform in criminal legislation.

(b) That the listed Acts replace “developmental disability of mind”, or variations of this term such as “developmentally disabled”, wherever they occur in the listed Acts, with “intellectual disability”.

(c) That an umbrella term, “impaired intellectual functioning”, be introduced into the listed Acts to cover all conditions which impair a person’s intellectual functioning (but not including mental illness) and that such a term be used wherever a policy decision is made that a provision in one of the listed Acts should apply to all people with such an impairment, however that condition arises, including intellectual disability, brain injury or dementia:

“impaired intellectual functioning” includes impaired intellectual functioning because of intellectual disability, brain injury or dementia.

1. E Cocks An Introduction to Intellectual Disability in Australia (Australian Institute on Intellectual Disability, Canberra, 1989) at 39.

2. For example: The Law Society of New South Wales Submission (24 August 1992) at 2; Australia. Attorney-General’s Department, Office of Legal Aid and Family Services Submission (28 August 1992) at 3; Queensland. Department of Family Services and Aboriginal and Islander Affairs Submission (18 August 1992) at 1; and Mr M Ierace Submission (16 December 1991) at 2. Many submissions have also expressed a preference for “people with an intellectual disability” rather than “the intellectually disabled”. The Commission acknowledges this comment and has used the phrase “people with an intellectual disability” in preference throughout this reference. See also, in this regard, the comments of L Gething, T Poynter and F Reynolds Disability Awareness Package - Manual (Community Disability and Ageing Program, University of Sydney, 1991) at 54.

3. For example: Legal Aid Commission of NSW Submission (24 July 1992) at 1; The New South Wales Council for Intellectual Disability Submission (16 September 1992) at 3; and Redfern Legal Centre Intellectual Disability Rights Service Submission (16 October 1992) at 2.

4. Gething, Poynter and Reynolds at 49.

5. Gething, Poynter and Reynolds at 48.

6. Cocks at 24.

7. A list of these and other myths about intellectual disability is provided in S C Hayes and G Craddock Simply Criminal (2nd ed, Federation Press, Sydney, 1992) at 24-26 and in Gething, Poynter and Reynolds at 57-58.

8. Hayes and Craddock at 25: “[i]ntellectually disabled people can learn more than is often assumed, but they learn at a slower pace and need educational programmes which are especially structured to their needs.”

9. Redfern Legal Centre Intellectual Disability Rights Service Submission (16 October 1992) at 2.

10. The World Health Organisation uses the following IQ ranges for these classifications: mild (IQ 50-69); moderate (IQ 35-49); severe (IQ 20-34); and profound (IQ less than 20): The ICD-10 Classification of Mental and Behavioural Disorders: Clinical descriptions and diagnostic guidelines (World Health Organisation, Geneva, 1992) at 227-230. Other categorisation systems vary slightly in IQ range.

11. Depending upon the classification system used, the “borderline” IQ range is approximately 70-79 or 70-85.

12. Hayes and Craddock at 25.

13. New South Wales. Law Reform Commission People with an Intellectual Disability and the Criminal Justice System (Discussion Paper 29, 1993) at para 1.4.

14. International Classification of Diseases (ICD-9, World Health Organisation, Geneva, 1977), now (ICD-10, 1992), from which the WHO’s International Classification of Impairments, Disabilities and Handicaps: A Manual of Classification relating to the Consequences of Disease (1980) was developed.

15. American Psychiatric Association Diagnostic and Statistical Manual of Mental Disorders (3rd ed, revised, Washington DC, 1987) (“DSM III-R”).

16. American Association on Mental Retardation Mental Retardation: Definition, Classification, and Systems of Supports (9th ed, American Association on Mental Retardation, Washington DC, 1992).

17. World Health Organisation The ICD-10 Classification of Mental and Behavioural Disorders: Clinical descriptions and diagnostic guidelines (World Health Organisation, Geneva, 1992) at 226.

18. DSM III-R at 28.

19. The AAMR’s previous definition of mental retardation was: “significantly sub-average general intellectual functioning existing concurrently with deficits in adaptive behaviour and manifested during the developmental period”: H J Grossman (ed) Classification in Mental Retardation (American Association on Mental Deficiency, Washington DC, 1983). The American Association on Mental Deficiency has been renamed as the American Association on Mental Retardation. It has been stated that the new definition does not significantly change the group of people who will be classified as “mentally retarded” and that the main change is the replacement of “adaptive behaviour” by “the more realistic and functional construct of requiring that the intellectual impairment be accompanied by related limitations in particular skills areas”: J W Ellis “Decisions by and for people with mental retardation: balancing considerations of autonomy and protection” (1992) 37 Villanova Law Review 1779, at 1782. Significantly, the terms representing levels of disability (“mild”, “moderate”, “severe” and “profound”) have been abandoned under the new definition. Classifications are still used, based on the individual’s support needs, classifying the individual’s need as “intermittent”, “limited”, “extensive” or “pervasive”, but these are not linked to IQ scores: see Ellis at 1784.

20. National Council on Intellectual Disability Submission (18 December 1991) at 1. Note that the submission was referring to the definitions used in 1991.

21. New South Wales. Attorney General’s Department The Intellectually Disabled in the Criminal Justice System (Criminal Law Review Division, Issues Paper, 1991) at 5; Mr M Ierace Submission (16 December 1991) at 2.

22. See Chapter 9.

23. New South Wales. Parliamentary Debates (Hansard) Legislative Assembly, 29 October 1987 at 15466.

24. Crimes Act 1900 (NSW) s 61J(2)(g), s 61M(3)(e) and s 61O(3)(d).

25. New South Wales Parliamentary Debates (Hansard) Legislative Assembly, 28 November 1989 at 13570.

26. New South Wales. Attorney General’s Department The Intellectually Disabled in the Criminal Justice System (Criminal Law Review Division, Issues Paper, 1991) at 6.

27. New South Wales Sexual Assault Committee Submission (August 1992) at 1.

28. The New South Wales Council for Intellectual Disability Submission (16 September 1992) at 4.

29. A separate Discussion Paper has been released covering these issues: New South Wales. Law Reform Commission Provocation, Diminished Responsibility and Infanticide (Discussion Paper 31, 1993).

30. For example, referring to the range of terms used in the Mental Health (Criminal Procedure) Act 1990 (NSW) and the Mental Health Act 1990 (NSW) (for example, mental illness, mental condition, developmentally disabled), the submission of the New South Wales Department of Courts Administration commented: “the complexity of the existing definitions would suggest that a judicial officer, even with the assistance of expert witnesses, may well encounter great difficulty in interpreting the definitions and discerning the shades of meaning that differentiate them. ... [A]ny attempt to simplify the definitions in the current legislation would be of great assistance to judicial officers whose lot it may ultimately be to interpret such provisions”: Submission (28 August 1992) at 2.

31. This definition is used in Victoria in the Intellectually Disabled Persons’ Services Act 1986 (Vic), s 3 and in the Crimes Act 1958 (Vic), s 50(1). According to these sections this definition applies only to a person over the age of five years.

32. Intellectual Disability Review Panel (Victoria) Submission (17 December 1992) at 2-3.

33. Intellectual Disability Review Panel (Victoria) Submission (17 December 1992) at 3.

34. Intellectual Disability Review Panel (Victoria) Submission (17 December 1992) at 4, and generally 3-5.

35. For example: The Law Society of New South Wales Submission (24 August 1992) at 2; Legal Aid Commission of NSW Submission (8 January 1992) at 2; The New South Wales Council for Intellectual Disability Submission (16 September 1992) at 4; Redfern Legal Centre Intellectual Disability Rights Service Submission (16 October 1992) at 2-3; Western Australia. Department of Corrective Services Submission (19 November 1991) at 1; and Associate Professor S C Hayes Submission (6 November 1991) at 1.

36. For example, comments made by Ms T Ovadia of the Mental Health Review Tribunal at a consultation with representatives of the Mental Health Review Tribunal and the Mental Health Advocacy Service on 11 March 1994.

37. The Law Society of New South Wales Submission (24 August 1992) at 2.

38. Legal Aid Commission of NSW Submission (24 July 1992) at 1.

39. Redfern Legal Centre Intellectual Disability Rights Service Submission (16 October 1992) at 3.

40. The New South Wales Council for Intellectual Disability Submission (16 September 1992) at 3-4.

41. Ms S E Maxwell, Solicitor, Legal Aid Commission of NSW Letter (3 December 1991) at 1.

42. Legal Aid Commission of NSW Submission (24 July 1992) at 1.

43. Mr M Ierace Submission (16 December 1991) at 2. See also The Law Society of New South Wales Submission (24 August 1992) at 2.

44. The Law Society of New South Wales Submission (24 August 1992) at 2.

45. See also New South Wales Sexual Assault Committee Submission (August 1992) at 1, which suggested that one alternative was “a definition which focuses on a person’s functioning and the effects or manifestations of intellectual disability ... [t]he focus should be on the person’s in/ability to function in society with adequate support.” See also the New South Wales Department of Family and Community Services [now Department of Community Services], Office on Disability Submission (26 November 1991) at 1, which stated: “[i]f there is a new definition it should not be based on IQ but on how intellectual disability affects function eg slow development of social skills.”

46. New South Wales Sexual Assault Committee Submission (August 1992) at 1.

47. Hayes and Craddock at 6-7, referring to S C Hayes and R Hayes Mental Retardation: Law, Policy and Administration (Law Book Co, Sydney, 1982) at ch 1.

48. J H Noble and R W Conley “Toward an epidemiology of relevant attributes” in R W Conley, R Luckasson and G N Bouthilet (eds) The Criminal Justice System and Mental Retardation: Defendants and Victims (Paul H Brookes Publishing Co, Baltimore, 1992) at 21-22.

49. Mr M Porter, Programme Director, Hunter Region Developmental Disability Service, Department of Community Services, New South Wales Submission (20 October 1992) at 1.

50. Redfern Legal Centre Intellectual Disability Rights Service Submission (6 January 1992) at 2.

51. The New South Wales Council for Intellectual Disability Submission (16 September 1992) at 4.

52. Associate Professor S C Hayes Submission (31 August 1992) at 3.

53. See, for example, R Perske Unequal Justice (Abingdon Press, Nashville, 1991), especially ch 7, referring to the availability of the death penalty.

54. The New South Wales Council for Intellectual Disability Submission (16 September 1992) at 4. See also Redfern Legal Centre Intellectual Disability Rights Service Submission (16 October 1992) at 3.

55. Illawarra Area Consultative Committee Submission (12 August 1992) at 2.

56. See footnote 19 above.

57. M Ierace Intellectual Disability: A Manual for Criminal Lawyers (Redfern Legal Centre Publishing, Sydney, 1989) at 3.

58. 70% of severe brain injuries are sustained in road accidents according to Cuff Consultants A Brain Injury Program for New South Wales: GIO’s Commitment Under Transcover (GIO, May 1987), cited in Department of Community Services Brain Injury: What is it all about? (July 1993) at 1.

59. According to a glossary provided by the New South Wales Department of Community Services: “[a]n individual is said to experience acquired brain injury when that injury is sustained and/or manifested after an initially unexceptional, predictable development. The terms: brain injury, head injury, traumatic head injury, traumatic brain injury and acquired brain injury, are all used to describe different aspects of brain injury. However, ‘acquired brain injury’ is the most inclusive term”: see Brain Injury: What is it all about? at 15.

60. Brain Injury: What is it all about? at 10.

61. Brain Injury: What is it all about? at 3-5. See also Mr G Simpson, Social Worker, Head Injury Outreach Team, Lidcombe Hospital Submission (21 February 1994) at 3-5.

62. Mrs Hunt Oral Submission (2 April 1993).

63. Mr G Simpson, Social Worker, Head Injury Outreach Team, Lidcombe Hospital Submission (21 February 1994) at 11

64. Noble and Conley at 20.

65. The Victorian Law Reform Commission (“VLRC”) in its report Mental Malfunction and Criminal Responsibility (Report 34, 1990) stated, at para 9, that it used “ ‘mental malfunction’ ... to cover all the ways in which a person’s mental condition may affect criminal responsibility, including conditions that arise from trauma or gross intoxication which fall outside the ambit of the insanity defence. A narrower term, ‘mental impairment’, is used to refer to conditions - like mental illness, intellectual disability, senility and brain damage - which do fall within the scope of the insanity defence.” The VLRC commented at footnote 1, however, that “[t]he term ‘mental malfunction’ is not an entirely satisfactory one - for example, intellectual disability is not a ‘malfunction’ but the normal state of the intellectually disabled person. Similar considerations apply to the inclusion of intellectual disability under the term ‘mental impairment’. However, for the sake of brevity, these terms have been used.” In its earlier report Sexual Offences Against People with Impaired Mental Functioning (Report 15, 1988), the VLRC made similar comments at paras 4-5 and used an umbrella term of ‘impaired mental functioning’, which is now used in the Crimes Act 1958 (Vic), s 50-51.

66. Criminal Law Officers Committee of the Standing Committee of Attorneys-General [now known as the Model Criminal Code Officers Committee] Model Criminal Code: Chapter 2 - General Principles of Criminal Responsibility (Final Report, AGPS, Canberra, 1992) cl 302, 302.1.

67. Autism, if it affects a person’s intellectual functioning and adaptive behaviour, would also fall within the proposed definition of intellectual disability.