The error, both chance and systematic, in the measure of true intellectual ability in the low IQ range is quantified and combined to find an overall confidence interval. The chance error was due to: lack of stability, scorer error and lack of internal consistency. The systematic error was due to: the Flynn effect, a floor effect and that error apparent from the lack of agreement between the WIS...

Assisted oocyte activation (AOA) using a calcium ionophore has been used for more than a decade following intracytoplasmic sperm injection (ICSI) fertilization failure. However, since AOA does not mimic precisely the physiological fertilization process, concerns exist about its use in human assisted reproduction. This study assessed the neonatal and neurodevelopmental outcome of children aged ≥...

The Wechsler Abbreviated Scale of Intelligence (WASI; Psychological Corporation, 1999) and the Wide Range Intelligence Test (WRIT; Glutting, Adams, & Sheslow, 2000) are two well-normed brief measures of general intelligence with subtests purportedly assessing verbal–crystallized abilities and nonverbal–fluid–visual abilities. With a sample of 152 children, adolescents, and adults, the present s...

It is assumed that attention problems (AP) are related to impaired executive functioning. We investigated the association between AP and inhibitory control and tested to what extent the association was due to genetic factors shared with IQ. Data were available from 3 independent samples of 9-, 12-, and 18-year-old twins and their siblings (1,209 participants). AP were assessed with checklists c...

In several studies, suppressed Digit Span performance has been proposed as a potential marker for deliberately poor performance in a neuropsychological evaluation. The purpose of this study was to document Digit Span performance patterns in the Wechsler Adult Intelligence Scale-Third Edition (WAIS-III; ) standardization sample and selected clinical groups. Base rate tables were generated for th...

The relationship between the Rorschach Prognostic Rating Scale (RPRS) and the Wechsler Adult Intelligence Scale (WAIS) was investigated to identify the factors, intelligence and others, which contribute to the RPRS. Correlation between the RPRS total and WAIS FSIQ showed that approximately 43% of the variance in the RPRS total can be accounted for by the variance in the FSIQ. Verbal IQ is not s...

Information on the rarity or abnormality of an individual's test scores (or test score differences) is fundamental in interpreting the results of a neuropsychological assessment. If a standardized battery of tests is administered, the question arises as to what percentage of the healthy population would be expected to exhibit one or more abnormally low test scores (and, in general, j or more ab...

Following the publication of the third edition Wechsler scales (i.e., WAIS-III and WMS-III), demographically corrected norms were made available in the form of a computerized scoring program (i.e., WAIS-III/WMS-III/WIAT-II Scoring Assistant). These norms correct for age, gender, ethnicity, and education. Since then, four new indexes have been developed: the WAIS-III General Ability Index, the W...

Hierarchical models of intelligence are highly informative and widely accepted. Application of these models to twin data, however, is sparse. This paper addresses the question of how a genetic hierarchical model fits the Wechsler Adult Intelligence Scale (WAIS) subtests and the Raven Standard Progressive test score, collected in 194 18-year-old Dutch twin pairs. We investigated whether first-or...