For nearly a century, twin and adoption studies have yielded substantial estimates of heritability for cognitive abilities, although it has proved difficult for genomewide-association studies to identify the genetic variants that account for this heritability (i.e., the missing-heritability problem). However, a new approach, genomewide complex-trait analysis (GCTA), forgoes the identification o...

Specific cognitive abilities in diverse domains are typically found to be highly heritable and substantially correlated with general cognitive ability (g), both phenotypically and genetically. Recent twin studies have found the ability to memorize and recognize faces to be an exception, being similarly heritable but phenotypically substantially uncorrelated both with g and with general object r...

An adoption/twin design was used to address issues concerning the relationship between education and Mini-Mental State Examination (MMSE) performance. Data on general cognitive abilities, education, and MMSE from 110 identical twin pairs and 177 fraternal pairs aged 50 through 88 were analyzed using multivariate quantitative genetic methods. Genetic influences account for 32% and 19% of the var...

OBJECTIVE To determine CASI-S accuracy in the diagnosis of dementia. METHOD The Cognitive Abilities Screening Instrument - Short Form (CASI-S) was applied in 43 Alzheimer's disease (AD) patients and 74 normal controls. AD diagnosis was based on DSM-IV, NINCDS-ADRDA, and CAMDEX. CASI-S includes: registration, temporal orientation, verbal fluency (4-legged animals in 30s), and recall (3 words)....

BACKGROUND Nonprobability Web surveys using volunteer panels can provide a relatively cheap and quick alternative to traditional health and epidemiological surveys. However, concerns have been raised about their representativeness. OBJECTIVE The aim was to compare results from different Web panels with a population-based probability sample survey (n=8969 aged 18-44 years) that used computer-a...

Although gender differences in cognitive abilities are frequently reported, the magnitude of these differences and whether they hold practical significance in the educational outcomes of boys and girls is highly debated. Furthermore, when gender gaps in reading, mathematics and science literacy are reported they are often attributed to innate, biological differences rather than social and cultu...

Cognitive deficits are consistently demonstrated in individuals with schizophrenia. Cognitive training involves structured exercises prescribed and undertaken with the intention of enhancing cognitive abilities such as attention, memory, and problem solving. Thus, cognitive training represents a potentially promising intervention for enhancing cognitive abilities in schizophrenia. However, cogn...

This chapter reviews primate cognitive abilities in physical, social, and communicative realms and asks (1) whether primates exhibit abilities that diff er from those of other animals, and (2) what selective pressures primates face that may have led to the emergence of specifi c cognitive abilities. The authors focus on communication as the most likely realm for primate cognitive specialization...

OBJECTIVE To develop an informant-based instrument that would provide a valid estimate of premorbid cognitive abilities in low-educated populations. METHODS A questionnaire was drafted by focusing on the premorbid period with a 10-year time frame. The initial pool of items was submitted to classical test theory and a factorial analysis. The resulting instrument, named the Premorbid Cognitive ...

Patients' cognitive abilities and verbal expressions of commitment to behavioral change predict different aspects of substance abuse treatment outcome, but these 2 traits have never been examined conjointly. The authors therefore investigated patients' cognitive abilities and verbal expressions of commitment to behavioral change as predictors of retention and drug use outcomes in an outpatient ...