INTRODUCTION

2.1 The Commission has been asked to consider whether there should be a new and uniform statutory definition of “intellectual disability”. A variety of definitions of “intellectual disability” or related terms are used in Australia. Many of the statutes and subordinate legislation which affect people with an intellectual disability have outdated or inaccurate terminology and definitions, or fail to provide a definition of the term at all. People with an intellectual disability are sometimes referred to as “mentally handicapped”, “mentally deficient”, “feeble minded”, “sub-normal” or “mentally retarded”, all terms which in present usage carry pejorative connotations. It has been pointed out that terms which use the word “mental” have “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 Also popular is the term “developmental disability”, although this is a broader term than intellectual disability, in that it refers to a number of other disabilities, such as cerebral palsy, which arise during the “developmental” period, which is usually defined as the period up until 18 years of age.

2.2 The Commission believes “intellectual disability” to be the appropriate descriptive term for the purposes of this Paper, and the appropriate term to be used in New South Wales’ legislation. It has already been adopted in Commonwealth and Victorian legislation. A preference for this term has been justified, in another context, as follows.

The term “intellectual disability” is used here because it is not connected with mental or physical illness. It is also a relatively recent term and has not yet gathered unduly negative connotations ... [It] acknowledges that with appropriate services and positive social attitudes, a disability need not become a handicap.²

It is also important to refer to “people” with an intellectual disability, rather than using a label as a noun to describe a person such as “the intellectually disabled”. The majority of people contacted in the course of this reference have emphasised the importance of a term which recognises the fact that people with an intellectual disability are “people first”. The Commission endorses that view and has adopted that usage wherever possible.

2.3 This Chapter considers a number of existing definitions currently used in New South Wales and raises the issue whether uniformity is possible or desirable. A fundamental problem with any definition of intellectual disability is that it involves drawing a line between people with an intellectual disability and those without such a disability. Definitions based on IQ (intelligence quotient) have been criticised, but definitions without such an independent standard may prove unworkable. Furthermore, a definition may be appropriate in one specific context but not in others. For example, the degree of intellectual disability which may be relevant for will-making capacity may be entirely different from that for fitness to plead or consent to sexual intercourse. It may be counter-productive to attempt to find one definition to cover a variety of contexts. It also should not automatically be assumed that a single, or in fact any, definition will be helpful for the operation of services and criminal procedures in relation to people with an intellectual disability. However, the Commission believes it would be useful and uncontroversial to eliminate terms which are archaic or derogatory.

STATUTORY DEFINITIONS OF INTELLECTUAL DISABILITY IN NSW

The Crimes Act

2.4 The Crimes Act 1900 (NSW) creates a number of sexual offences against people with an intellectual disability, and defines “intellectual disability”, in s 66F(1), as:

an appreciably below average general intellectual function that results in the person requiring supervision or social habilitation in connection with daily life activities.

This definition has been criticised as 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.³ 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.

2.5 The Crimes Act also refers, in other sections dealing with sexual offences,⁴ to “serious intellectual disability” as a "circumstance of aggravation". The Attorney General’s Committee made the following comments about this terminology:

... Not only is there no definition of the term for the purpose of those sections but the word “serious” is an addition to the term not generally used by psychologists. The common understanding of a scale of intellectual disability among psychologists is “borderline”, “mild”, “moderate” and “severe” or “profound”. As the term “serious” does not feature in this scale, consideration should be given to either amending the sections to replace “serious” with a more meaningful term or defining the word “serious” in that context, particularly given the considerable degree of disability which is implied by the definition [of intellectual disability] ... and the fact that it is the only current NSW statutory definition.⁵

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 ...

Such a definition is likely to include some people with an intellectual disability, depending upon the severity of their disability. This and other substantive criminal law defences are raised in Chapter 5.

Other statutes

2.7 The Mental Health (Criminal Procedure) Act 1990 (NSW) refers, in s 32, to defendants who are “developmentally disabled”. No definition is provided for this term, although it is usually taken to refer to a wider group than “intellectually disabled”. “Developmental disability” has been described as:

a broad term that usually covers categories such as intellectual disability, cerebral palsy, epilepsy, autism, and some neurological conditions ... The term developmental disability has advantages when applied to young children where a delay in development may be clear, but a diagnostic cause or label not so clear ... It is also a term which is less stigmatising than others and thus easier for families and the community to come to terms with.⁶

The Department of Community Services also uses, for the purpose of service provision, the term “developmental disability”, describing it as a severe chronic disability which:

(a) is attributable to an intellectual or physical impairment or combination of intellectual or physical impairments;

(b) is manifested before the person attains age 18;

(c) is likely to continue indefinitely;

(d) results in substantial functional limitation in three or more of the following areas of major life activity: self-care, receptive and expressive language, learning, mobility, self-direction, capacity for independent living, economic self-sufficiency, and

(e) reflects the person’s need for a combination and sequence of special inter-disciplinary or generic care, treatment, or other services which are of lifelong or extended duration and are individually planned and co-ordinated.




For practical purposes this includes persons with intellectual handicap, severe epilepsy, cerebral palsy, brain damage acquired in childhood, and those with other neurological disorders needing similar provision.⁷

However, “developmental disability”, or “DD”, appears to be used colloquially as a synonym for intellectual disability, which people with physical disabilities may find offensive or inappropriate.

2.8 The Anti-Discrimination Act 1977 (NSW) prohibits discrimination on the ground of “intellectual impairment”, which is defined, in s 4, as:

any defect or disturbance in the normal structure and functioning of the person’s brain, whether arising from a condition subsisting at birth or from illness or injury.

An “intellectually handicapped person” is defined in the same section as “a person who, as a result of disabilities arising from intellectual impairment, is substantially limited in one or more major life activities”. The Anti-Discrimination Board of New South Wales has acknowledged that these provisions have given rise to several difficulties.⁸ It has made a submission to the New South Wales Government recommending several changes to the definition of “impairment”, including amalgamating the definitions of physical and intellectual impairment into one definition, namely:

any defect or disturbance in the normal structure or functioning of a person including the presence of an organism which may cause disease.

The Board also recommended the deletion of the requirement that a person with an impairment also be “handicapped”. Discrimination would then be made out if a person with an impairment (past, present or imputed) was treated less favourably, on the ground of the impairment, than a person without an impairment. The Law Reform Commission currently has a reference to review the scope of the Anti-Discrimination Act and this issue is likely to be considered further in the course of that reference.

The Commission seeks comments about the merits or otherwise of the statutory definitions discussed above, including whether these definitions cause practical problems and whether any cause offence.

OPERATIONAL DEFINITIONS

2.9 Apart from statutory definitions, government departments are likely to use “operational” definitions to provide a qualifying definition for services; for example, the Department of Community Services uses the definition of developmental disability set out at para 2.6 above. The Department of Corrective Services also uses an operational definition to define intellectual disability for the purpose of admission to specialist units; namely, either an IQ below 70 or an IQ of 70-80 together with severe adaptive deficits, (see Chapter 6). Government departments need clear definitions to allow the fair distribution of services, particularly where the demand may be higher than the availability.

The Commission seeks information about other operational definitions used within the criminal justice system, and their effectiveness.

CLINICAL DEFINITIONS

2.10 There are a number of commonly used clinical definitions of intellectual disability: see, for example, the International Classification of Diseases (1977) (ICD-9), the manuals of the American Association on Mental Retardation (AAMR) and the American Psychiatric Association’s Diagnostic and Statistical Manual III-R (DSM III-R).⁹ All of these classifications use IQ scores as both a criterion for intellectual disability and also as a means of distinguishing between different levels of disability.

2.11 The usual clinical definition of intellectual disability is sub-average general intellectual functioning, that is, an IQ of approximately 70 or less on a recognised test of intelligence, such as the “Weschler Adult Intelligence Scale - Revised” (WAIS-R), and deficiencies in social and adaptive skills.¹⁰ Four categories of intellectual disability have traditionally been used - mild, moderate, severe and profound - based upon IQ assessments, where an IQ of 100 is average.¹¹ The usefulness of these categories and the reliability and validity of IQ scores, however, have been questioned. Significant differences between IQ scores obtained from the same individual on different occasions can occur which are unrelated to the individual’s intellectual ability. An individual’s performance will be affected by variations in factors such as motivation. Tests which are designed to be administered to the whole population have less validity when applied to a sub-group which is at the extreme of the distribution produced by administering the test. It has also been claimed that IQ tests contain cultural biases.

ADVANTAGES AND DISADVANTAGES OF UNIFORMITY

2.12 There is an obvious advantage in having uniformity of terminology in New South Wales statutes, though non-criminal statutes affecting people with an intellectual disability may fall outside the terms of the Commission’s reference. One submission noted that, to avoid confusion, such a 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.¹² Many of the definitions set out above were drafted to fulfil specific purposes within the Acts in which they appear. They are thus not always easily extended beyond the parameters of that particular piece of legislation.

2.13 It also may be argued that there are dangers in attempting to define intellectual disability, as it is a term which can be applied to a condition affecting many different people in diverse ways and arising from a variety of causes. A strict definition may leave out 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 develop an intellectual disability as a result of an accident or injury in adulthood. One submission noted that people with head injuries leading to an intellectual disability should not be overlooked.¹³ An overly technical definition may also lead to problems of accurate identification and application. Another submission argued that there was a danger in using a definition which could be manipulated by an accused to pretend to have an intellectual disability to gain some advantage, such as a lighter sentence.¹⁴ Definitions may also increase the “labelling” of people with an intellectual disability, with its pejorative overtones. Many people do not wish to be identified as having an intellectual disability and fear that, with such a label, they may be treated worse, not better, within the criminal justice system.

QUESTIONS FOR DISCUSSION

2.14 The Commission welcomes comment as to the deficiencies or the merits of the existing definitions of intellectual disability discussed above. In particular it seeks answers to the following questions:

• Is it possible to draft a uniform definition of intellectual disability? If so, how should such a definition be phrased, and to which New South Wales laws should it be applied?
• If it is possible to draft such a definition, would its disadvantages outweigh its advantages?

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

2. Cocks at 41.

3. New South Wales. Attorney General’s Department The Intellectually Disabled in the Criminal Justice System (Issues Paper, 1991) at 6; Mr M Ierace Submission (16 December 1991) at 2.

4. Sections 61J(2)(g), 61M(2)(e) and 61O(3)(d).

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

6. Cocks at 24.

7. New South Wales. Department of Community Services, Aging & Disability Services Submission (21 January 1992). This definition is similar to the definition of “developmental delay” found in s 3 of the Intellectually Disabled Persons’ Services Act 1986 (Vic).

8. Anti-Discrimination Board of NSW Submission (12 November 1991).

9. ICD-9 describes “mental retardation” as “a condition of arrested or incomplete development of mind which is especially characterised by subnormality of intelligence”. The World Health Organisation’s International Classification of Impairments, Disabilities and Handicaps (1980) is an extension of ICD-9 and defines intellectual disability as arising from an intellectual impairment which is determined by reference to IQ levels. The AAMR's Classification in Mental Retardation (8th revision, 1983) adopted the following definition of intellectual disability: “significantly subaverage general intellectual functioning resulting in or associated with concurrent impairment in adaptive behaviour and manifested during the developmental period.” The DSM III-R (1987) identifies three essential features of “mental retardation”: (1) significantly subaverage general intellectual functioning (defined as an IQ of 70 or below), accompanied by (2) significant deficits or impairments in adaptive functioning, with (3) onset before the age of eighteen. See Cocks, especially Part Five.

10. S C Hayes and D McIlwain The Prevalence of Intellectual Disability in the New South Wales Prison Population: An Empirical Study (November 1988) at 8.

11. The World Health Organisation categories are: mild (IQ 52-67), moderate (IQ 36-51), severe (IQ 20-35) and profound (IQ under 20). A further category, borderline (IQ 68-85), has been suggested. The AAMR Classification System uses a slightly different range: mild (IQ 50-55 to approx. 70), moderate (IQ 35-40 to 50-55), severe (IQ 20-25 to 35-40) and profound (IQ below 20-25).

12. Mr M Ierace Submission (16 December 1991) at 2.

13. Disabled Peoples International NSW Inc Submission (23 January 1992).

14. Senior Constable P Fernandez, Wagga Wagga, Submission (8 December 1991) at 1.