Often in Atkins MR/ID death penalty cases historical and contemporary IQ
scores are available for review by psychological experts. In many cases these scores vary
markedly. The courts frequently wrestle
with the issue of determining what the best estimate is of the person’s general
intelligence. A review of many Atkins cases often reveals frequent
mention of two “gold standard” IQ
tests in reports or testimony—namely, the Stanford-Binet
and the Wechsler series.
The purpose of
this working paper is to alert psychologists and the courts to two little known
(but extremely important) dents in the gold standard status of two versions of
the Stanford-Binet—the 1960 SB and
the 1986 SB IV. If a Flynn effect
adjustment is made to scores from a 1960 SB, the norm date used to calculate
the magnitude of the Flynn effect should be 1932…not 1960. If SB IV
scores exist in an individual’s records, experts providing opinions regarding
the individual’s general level of intelligence should consider: (a) eliminating
the score from consideration, (b) not give the score great weight in
formulating an opinion, or (c) at a minimum, provide qualifying statements
regarding the validity of the SB IV score as required by the Joint Test Standards.
IAP Applied Psychometrics 101 Report # 13 can be downloaded by clicking here.
