This presentation traces the evolution of psychometric theories of intelligence from Spearman's g to contemporary CHC. In addition, it simultaneously tracks the evolution of psychometric tests of intelligence as they relate to psychometric theories. Finally, there is a special emphasis on tracking changes in the AAMR/AAIDD intellectual disability (mental retardation) classification manuals over the same period. It is concluded that despite significant advances in psychometric theories of intelligence and contemporary psychometric intelligence tests, the official 2010 AAIDD manual is significantly behind these developments. The 2010 AAIDD manual is "stuck on g" and has failed to incorporate advances in both psychometric theories and tests of intelligence. A significant intelligence theory--AAIDD ID/MR definition gap exists tat has potential serious consequences for individuals with ID/MR.