What is the legal test for intellectual disability?

The professional psychological community continues to refine its understanding of these concepts. For our purposes here, intellectual disability is "a question of fact ... 'not measured according to a fixed intelligence test score or a specific adaptive behavior deficiency, but rather constitutes an assessment of the individual's overall capacity based on a consideration of all the relevant evidence.' " ( People v. Superior Court (Vidal ) (2007) 40 Cal.4th 999, 1012, 56 Cal.Rptr.3d 851, 155 P.3d 259 ; see id. at p. 1012, fn. 6, 56 Cal.Rptr.3d 851, 155 P.3d 259.)