The survey covered 10% of the prison population. Psychologists visited all 14 prisons in the State. Alphabetical lists of the inmates were drawn up and each tenth prisoner on the lists was interviewed, unless he or she was considered by the governor or his representative to be unsuitable for the purpose. The vast majority of prisoners asked to co-operate with the study did so. During the one hour interview a number of assessments were made, including the Kaufman Brief Intelligence Test which examines reading, writing and mathematical ability. To their horror, the researchers discovered that 28.8% of the prison population scored below 70% in the test, which denotes severe disability or mental handicap. The equivalent level in the general population is 2% to 3%. What was also extraordinarily worrying was that a comparison of the scores here with those of prison populations in other countries, for example, Australia and the United Kingdom, found that the scores of prisoners elsewhere were very similar to those in the respective general population. Ours, on the other hand, were ten times higher.