Thursday Law Report: Evidence of more than IQ test might be needed

4 November 1999

Megarry v Chief Adjudication Officer

Court of Appeal (Lord Justice Simon Brown, Lord Justice Otton and Lord Justice Mummery) 29 October 1999

WHILST THE expression "severe impairment of intelligence and social functioning" in regulation 12(5) of the Social Security (Disability Living Allowance) Regulations 1991 required that two separate conditions should be satisfied, in some cases at least an impairment of social functioning would shade into an impairment of intelligence, and in such cases evidence other than that of a mere IQ score would be necessary when considering whether a claimant suffered "severe impairment of intelligence".

The Court of Appeal allowed the claimant's appeal against the decision of the Social Security Commissioner that he was not "severely mentally impaired" within the terms of section 73(3) (a) of the Social Security Contributions and Benefits Act 1992.

The claimant was an autistic child aged nine. The Disability Appeal Tribunal found him entitled to the highest rate of the care component of a disability living allowance, and to the lower rate of the mobility component, but rejected his claim under section 73(3) of the Social Security Contributions and Benefits Act 1992 to the higher rate of the mobility component. The Social Security Commissioner dismissed the claimant's appeal against that decision, on the ground that he was not "severely mentally impaired" as required by section 73(3)(a).

Regulation 12(5) of the Social Security (Disability Living Allowance) Regulations 1991 provided that:

A person falls within sub-section (3)(a) of s 73 of the Act . . . if he suffers from a state of arrested development or incomplete physical

development of the brain which results in severe impairment of intelligence and social functioning.

The Commissioner held that in order to satisfy the condition in regulation 12(5) the claimant had to establish that his autism resulted in both (a) severe impairment of intelligence and (b) severe impairment of social functioning; that to establish that he suffered "severe impairment of intelligence" he had to show that he had an IQ of 55 or less; that there was no evidence to that effect, so that the claim failed; and that since he had failed to establish that he suffered "severe impairment of intelligence" it was unnecessary to consider whether he suffered "severe impairment of social functioning".

The claimant appealed, submitting that it was wrong to construe the expression "severe impairment of intelligence and social functioning" as implying two distinct requirements; and that, even if that were wrong, it could not, nevertheless, be right, least of all in the case of an autistic claimant, to decide whether he suffered "severe impairment of intelligence" solely by reference to whether his IQ exceeded 55.

Simon Cox (Solicitor for Disability Law Service) for the claimant; Richard McManus QC (Solicitor for the Department of Social Security) for the respondent.

Simon Brown LJ said that in the great majority of cases the two elements of intelligence and social functioning would be widely disparate, and accordingly the Commissioner had been right to construe the expression "severe impairment of intelligence and social functioning" as requiring that two discrete conditions be satisfied.

The Commissioner had, however, erred in regarding the limitation on the claimant's social functioning as wholly irrelevant. Had the maker of the regulations wished to define "severe impairment of intelligence" exclusively by reference to an IQ he could easily have done so.

Whilst in every case the claimant's IQ as conventionally tested was likely to be the essential starting point for considering the impairment of intelligence, and whilst it was perfectly reasonable to take an IQ of 55 or less as the prima facie touchstone of severe impairment, that test and that score would not invariably prove decisive. Rather it should be recognised that an IQ result might give a misleading impression of the claimant's useful intelligence, and that in some cases at least an impairment of social functioning would shade into an impairment of intelligence. Tribunals and Commissioners would accordingly need to admit and consider evidence other than a mere IQ score.