Tethering the elephant: Capital cases, IQ, and the Flynn effect.

Capital offenders cannot be executed if they are mentally retarded. Therefore, the IQ scores of offenders are important, and the U.S. 4th Circuit Court of Appeals has held that the Flynn effect is relevant to interpreting their IQ scores. The Flynn effect (IQ gains over time) means that different IQ tests will give different scores purely as a result of when the tests were normed. Because execution must not be a random result of what test defendants take, a formula is provided to convert IQ scores to a common metric: the norms current at the time the test was taken. The formula also includes a correction based on evidence that the Wechsler Adult Intelligence Scale-Third Edition inflates IQs because of sampling error. Given the inevitability that opposing experts will offer conflicting diagnoses, IQ scores merit special attention in capital cases. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effect of the Fragile X Status Categories and the Fragile X Mental Retardation Protein Levels on Executive Functioning in Males and Females With Fragile X.

The effects of a fragile X disorder on executive function impairment were assessed in 144 extended families, which included individuals with fragile X premutation and full mutation and their relatives without fragile X. A modification of the maximum-likelihood estimators for pedigree data, as well as ordinal logistic regression, were used in data analysis. The most outstanding deficit, occurring especially in males, involved impaired capacity to use an intention to regulate purposeful behavior. This deficit occurred independently of general cognitive impairment but was related to depletion of fragile X mental retardation 1 gene protein product. The other executive function deficits were accounted for by the general cognitive impairment. Possible mechanisms of the effect of fragile X premutation on impairments of executive functioning are considered. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The Impact of Childhood Intelligence on Later Life: Following Up the Scottish Mental Surveys of 1932 and 1947.

The Scottish Mental Surveys of 1932 and 1947 collected valid IQ-type test scores for almost everyone born in 1921 and 1936 and attending school on June 1, 1932 (N=89,498) and June 4, 1947 (N=70,805). These surveys are described. This research, using the surveys' data, examined (a) the stability of intelligence differences across the life span, (b) the determinants of cognitive change from childhood to old age, and (c) the impact of childhood intelligence on survival and health in old age. Surviving participants of the Scottish Mental Surveys were tested, and the surveys' data were linked with public and health records. Novel findings on the stability of IQ scores from age 11 to age 80; sex differences in cognitive aging; the dedifferentiation hypothesis of cognitive aging; and the effect of childhood IQ on all-cause and specific mortality, morbidity, and frailty in old age are presented. (PsycINFO Database Record (c) 2010 APA, all rights reserved)