MAJOR FINDINGS
4.1 In this study, using an untimed test of fluid intelligence (the matrices section of the Kaufman Brief Intelligence Test: K-BIT), 20.9 per cent of subjects obtained a standard score (SS) between 70 and 79, in the borderline category of intelligence, and 36.0 per cent obtained a SS less than 70, and could be described as intellectually disabled. A total of 58.1 per cent fell at or below a percentile rank of 10 which means that they would be performing at a level lower than 89 per cent of the population; 27.9 per cent were at or below a percentile rank of 1, that is below 98 per cent of the population.
4.2 A second major finding is that 40.7 per cent of the sample tested fell below the cut off point on the Mini-Mental State Examination (MSE) which indicates a need for further mental state assessment. This group may include people who have psychiatric problems, who are severely affected by stress, intoxicated by drugs or alcohol, who have difficulty with English language proficiency, and may include some who have an intellectual disability.
4.3 There is some correlation between the K-BIT and the MSE, particularly on the subsections of Orientation, Location, Serial Sevens, and Backwards Spelling, subtests which may be to some extent influenced by school-learnt skills. Nevertheless, each test identified some subjects as “cases” who were not so identified by the other test, indicating that to some extent each test assessed different mental factors.
4.4 A total of 49 individuals had a SS on the K-BIT of <80, and 35 had an MSE score of <22. Identification as a “case” on both tests occurred for 30 subjects, whereas a further 5 persons on the MSE and a different 19 on the K-BIT were identified as falling below the relevant cut off points on each of the scales. Thus, a total of 54 individuals (61.4 per cent of the total sample) had scores on one or both tests which indicate that for some reason they would have serious difficulty in comprehending or coping with court procedures, and may need further expert assessment which could be relevant to the conduct and outcome of their court matter.
4.5 The difficulty in recognising the accused person with intellectual disability was highlighted by the fact that 18 of the 31 persons with a SS<70, and 14 of the 18 with SS 70-79 were not identified by the research officers as having intellectual deficits. The false positives were less likely to occur - no respondent with SS>80 was incorrectly classified as having an intellectual disability indicating that people of average intelligence are unlikely to be erroneously classified as having an intellectual disability. No criticism of the researchers is intended - rather the findings reflect the difficulty encountered by lawyers and other professionals attempting to identify the presence of intellectual disability amongst people appearing before courts.
4.6 According to discriminant analysis, respondents with SS<70 were more likely to be unemployed, to receive a pension, to have a low MSE score especially on the Serial Sevens and Location subtests, and were more likely to have been drinking on the day of the alleged offence.
REPRESENTATIVENESS OF THE SAMPLE
4.7 The sample included 98 per cent of persons listed to appear on list days in Bourke and Brewarrina Courts during July 1995, and being such a comprehensive sample, could be said to be representative of persons appearing before these local courts.
4.8 The sample was not significantly different from New South Wales local court statistics for gender. There was, however, a greater proportion of Aborigines in the sample (73.9 per cent) than occurs in prisons (14.6 per cent). Statistics have not been located describing the proportion of Aboriginal persons appearing before New South Wales local courts in general. As a consequence of the high proportion of Aborigines, the proportion of persons born in Australia was higher than the population for New South Wales.
4.9 Unemployed persons were over-represented in comparison with the New South Wales population, although the rate of unemployment was similar to the previous court cohort study reported in RR 4.1 It has been well demonstrated that persons appearing before courts who can establish that they have secure employment are more likely to receive lenient sentences,2 a finding which implies that this sample will be at a disadvantage during the sentencing proceedings.
4.10 The sample was slightly under-represented for 19 year old persons, compared with New South Wales local court statistics, and slightly over-represented in the 25-29 age range, but the differences were not statistically significant.3
4.11 The offences recorded for the sample were dissimilar from the 1994 New South Wales local court profile, with the sample being over-represented for offences against the person, under-represented for break and enter, under-represented for drug offences and for driving offences. These findings may be affected by the high proportion of Aborigines and people with intellectual disability in the sample. Aborigines are over-represented in figures for imprisonment for assault, but less likely to be in prison for drug offences or robbery.4 Thus the pattern of offences reported by the sample, whilst differing from the overall New South Wales local court appearances, nevertheless is fairly typical of the pattern of offences for Aboriginal accused persons (see Chapter 1 - Types of Offences). Research has found that people with intellectual disability are most frequently convicted of offences against the person.5 In comparison with RR 4, this sample had a higher proportion of offences against the person, but were lower on drug offences.
4.12 Given the comprehensive nature of the sample, there is no reason why it could be supposed that this sample is atypical of persons appearing before these two local courts in New South Wales. The courts were chosen for the likelihood of having a high proportion of Aboriginal appearances, and some of the other parameters upon which the sample differs from New South Wales general population statistics or from New South Wales local court figures may be directly related to the high proportion of Aboriginal persons. Other research indicates that intellectual disability, communication difficulties, and social and adaptive skills deficits are relatively common amongst Aboriginal prisoners, perhaps related to poor access to health care especially in the pre-natal period, and to other health deficits.6
4.13 A total of 12.0 per cent of participants indicated that they were not legally represented, a finding which was indicative of a higher rate of legal representation than occurs generally in New South Wales courts (37.7 per cent being unrepresented in New South Wales local courts in 1994), and also in comparison with RR 4 (30 per cent being unrepresented).
ALCOHOL AND DRUG CONSUMPTION
4.14 An additional series of questions pertaining to drug and alcohol consumption was included in the survey form in this study. Four out of five (81.2 per cent) of those who responded to the question concerning drinking alcohol on the day of the offence answered in the affirmative. Those who had a SS of <70 did not differ significantly from those who scored over 70 although it is worth noting that 90% of those with an SS<70 had been drinking on the day of the alleged offence compared with 56% of those with SS>100. The most striking feature was the amount of alcohol said to have been consumed. Nearly the same proportion (79.4 per cent) indicated that they were intoxicated at the time of the offence.
4.15 A smaller proportion (12.7 per cent) had consumed drugs on the day, and amongst illegal drugs, marijuana was the most frequently cited. Most of those who had consumed marijuana indicated that they had also consumed at least two cartons of beer or the equivalent amount of other alcoholic drinks.
THE COMBINED SAMPLE
4.16 For the total sample of persons in RR 4 and the current study, the group was over-represented in terms of Aboriginality compared with Aborigines in prison,7 and unemployment, compared with the New South Wales population.8
4.17 Nearly one quarter (23.6 per cent) had a SS<70, that is, in the category of intellectual disability, and a further 14.1 per cent obtained SS 70-79, in the borderline range of ability.
4.18 Aboriginal/Islander respondents were more likely to have lower SS.
4.19 Results on the K-BIT were significantly related to results on the MSE, although the overlap is not total. These results indicate that MSE cannot be substituted for a test of general intelligence.
4.20 In the total sample, when high and low scorers were compared on the K-BIT, low scorers (below 70) were more likely to be Aboriginal/Islander, to be unemployed, and to perform poorly on the Serial Sevens and Backwards Spelling subtests (two subtests which are relatively reliant upon school learnt skills).
4.21 Discriminant analysis performed to distinguish between Aboriginal and non-Aboriginal participants found that the former were more likely to obtain low scores on the K-BIT and the Orientation subtest of the MSE, but to do better on Location and Backwards Spelling.
4.22 Within the Aboriginal/Islander group, the factors which discriminated between high and low performers of the K-BIT were Serial Sevens and Location, indicating that general mental state may be an important factor in the Aboriginal group, and the presence of a dual diagnosis may affect K-BIT results.
4.23 Women in the total sample differed from men in that they were more likely to not be receiving a pension, to be unemployed, to have a low MSE score, and to be older.
4.24 The results of discriminant analyses must be regarded with caution owing to the fact that only limited variables could be entered into the analyses, and variables with high levels of missing data had to be excluded.
CONCLUSIONS
4.25 In a total sample drawn from six local courts in New South Wales, more than one in four persons had a standard score (SS) of less than 70 and a further 14.2 per cent had SS between 70-79.
4.26 In two rural courts with a high Aboriginal population, 36.0 per cent had SS<70 and 20.9 per cent fell between SS 70-79. Seven per cent obtained a SS<50 placing them in the range of moderate intellectual disability.
4.27 As in RR 4, social and adaptive skills were not assessed, owing to privacy considerations in the relatively public environment of a court house. Had social and adaptive skills evaluation taken place, however, some of the borderline group may have been included in the mild intellectual disability category using the definition of intellectual disability which includes cognitive functioning as well as adaptive skills deficits in two or more areas.
4.28 On an assessment of mental state (MSE), 41.7 per cent of the second sample fell below the cut off point indicating the need for further mental state examination. Of the combined sample, 35.5 per cent fell below this cut off point.
4.29 These results indicate that in rural jurisdictions with a high Aboriginal population, more than half of the accused persons appearing before the local courts are likely to have significant difficulty in understanding court proceedings. Furthermore, their mental and/or cognitive state may have had significant bearing upon the commission of the offence(s).
4.30 Alcohol appears to have been consumed by most of the sample on the day of the alleged offence, and may have played a contributory part in the behaviour leading to apprehension by police.
4.31 Aboriginal persons appear to be significantly more at risk than non-Aboriginal people in both cognitive function and other mental state abnormality.
4.32 Although every effort was made to use culture-fair assessments, the possibility cannot be dismissed that Aboriginal people are disadvantaged by the K-BIT and the MSE. The K-BIT was chosen because it is an untimed, non-verbal test of cognitive reasoning which relies upon interpretation of patterns and pictures of objects which should be as familiar to Aboriginal people as they are to other rural and urban dwellers in Australia. Research indicates, however, that even a test which has been designed to be culture-fair (the Cattell Culture Fair Intelligence Test - CFIT) has items which are biased culturally and which may not have universal validity as a measure of fluid intelligence.9 The CFIT has been found to correlate with another mental ability test, and white institutionalised delinquents in the USA did better on the CFIT than on the other brief measure of intelligence, but concurrent and predictive validity for different ethnic groups needs to be researched.10 As outlined in paras 2.14-2.26, however, the available evidence suggest that the K-BIT does not have any consistent cultural bias.
4.33 A study on urban and rural Aboriginal children matched with urban and rural Anglo-Australian children found that urban students scored higher than rural students and Anglo-Australians scored higher than Aborigines. Both psychometric test intelligence and cognitive style accounted for significant proportions of the variance shared by environment (cultural and location) and scholastic achievement. Psychometric intelligence was, however, a more powerful predictor of the effects of culture and location on school achievement than was cognitive style, that is, the way people from different cultures analyse problems.11 Students scoring high on tests of cognitive ability could be less influenced by cultural factors or urban/rural location than those who are low scorers. Thus high levels of performance may be a protective factor against the cultural bias of tests, more so than cognitive style.
4.34 Very little is known about intellectual disability amongst Aboriginal populations, and where data are available they are usually included as part of epidemiological studies of psychiatric disorders. Seldom have psychometric tests been used to establish cognitive and adaptive skills deficits.12
4.35 Further research is needed to investigate the reasons why this rural sample appeared to perform worse than the previous court cohort sample, and why Aboriginal people in particular appear to be at a disadvantage in the criminal justice system. Given the poor health indicators and high levels of mortality and morbidity for the Aboriginal population,13 it would not be surprising if intellectual abilities were affected along with physical health. The factors which contribute to the over-representation of Aboriginal people in the criminal justice system, and which pose difficulties for this group in understanding and dealing effectively with court processes need to be researched further so that, in conjunction with Aboriginal people, effective means of addressing these problems can be developed.
FOOTNOTES
1. New South Wales Law Reform Commission People with an Intellectual Disability and the Criminal Justice System: Appearances Before Local Courts (Research Report 4, Sydney, 1993).
2. See Research Report 4, para 1.38; and F Gale Aboriginal Youth and the Law: Problems of Equity and Justice for Black Minorities (Australian Studies Centre, University of London, London, 1985).
3. NSW Bureau of Crime Statistics and Research New South Wales Criminal Court Statistics 1994 (NSW Attorney General’s Department, Sydney, 1995).
4. D Biles “Aboriginal Imprisonment - A Statistical Analysis” in D Biles and D McDonald (eds) Deaths in Custody Australia, 1980-1989 (Australian Institute of Criminology, Canberra, 1992) 85-105.
5. S C Hayes and G Craddock Simply Criminal (2nd ed, Federation Press, Sydney, 1992).
6. S Hayes and D McIlwain The Prevalence of Intellectual Disability in the New South Wales Prison Population: An Empirical Study (Report to the Criminology Research Council, Canberra, 1988).
7. Biles (1992).
8. New South Wales Year Book 1995 (No 75, Australian Bureau of Statistics, NSW, 1995).
9. N J Nenty “Cross-culture Bias Analysis of Cattell Culture-Fair Intelligence Test” Perspectives in Psychological Researches 1986; 9(1): 1.16.
10. J P Haynes, R C Howard and D Atkinson “Concurrent and predictive validity of two group intelligence tests in a juvenile forensic setting” Psychological Reports 1983; 53(1): 187-189.
11. L A Clark and G S Halford “Does cognitive style account for cultural differences in scholastic achievement?” Journal of Cross-Cultural Psychology 1983; 14(3): 279-296.
12. J P Reser “Aboriginal Mental Health: Conflicting Cultural Perspectives” in J Reid and P Trompf (eds) The Health of Aboriginal Australia (Harcourt Brace, Sydney, 1991) 218-291.
13. Reid and Trompf (1991).
