The presence of general intelligence poses a major evolutionary puzzle, which has led to increased interest in its presence in nonhuman animals. The aim of this review is to critically evaluate this question and to explore the implications for current theories about the evolution of cognition. We first review domain-general and domain-specific accounts of human cognition in order to situate att...

Eye movements help to infer the cognitive strategy that a person uses in fluid intelligence tests. However, intelligence tests demand different relations/rules tokens to be solved, such as rule direction, which is the continuation, variation or overlay of geometric figures in the matrix of the intelligence test. The aim of this study was to understand whether eye movements could predict the out...

Subtest analysis is pervasive in psychological training and practice. That is, the speculation that the variability or profile of an individual's scaled scores across the subtests of an intelligence test have meaning beyond that provided by global IQ measures. A review of subtest analysis research revealed that neither subtest scatter nor subtest profiles demonstrate acceptable accuracy in disc...

The German Observational Study of Adult Twins (GOSAT) is the largest population-based observational twin study in Germany to date. Embedded in the Bielefeld Longitudinal Study of Adult Twins (BiLSAT), it addresses the etiology of personality, temperament and cognitive ability in a sample of 300 monozygotic (MZ) and dizygotic (DZ) adult twin pairs between 18 and 70 years of age. A major aim of t...

The purpose of this study was to compare the effectiveness of two kinds of reinforcements, tangible reinforcements and social reinforcements, on the academic achievement of eighth-grade female students with intellectual disabilities in the science subject. The study was an experimental method by pretest, with a control group. The participants of the study comprised 45 female students with intel...

Recent reports of training-induced gains on fluid intelligence tests have fueled an explosion of interest in cognitive training-now a billion-dollar industry. The interpretation of these results is questionable because score gains can be dominated by factors that play marginal roles in the scores themselves, and because intelligence gain is not the only possible explanation for the observed con...

In this paper, we review current issues in cognitive assessment. After addressing important definitional and theoretical issues, we discuss some recently developed cognitive assessment instruments as well as some recently revised instruments. Tests that are scheduled for revision will also be mentioned. As most readers are generally familiar with the widely used and nationally standardized IQ t...

Self-reports, peer reports, intelligence tests, and ratings of personality and intelligence from 15 videotaped episodes were collected for 600 participants. The average cross-situational consistency of trait impressions across the 15 episodes was .43. Shared stereotypes related to gender and age were mostly accurate and contributed little to agreement among judges. Agreement was limited mainly ...

The significant increase in IQ in the industrialised countries during recent decades, known as the eponymous Flynn Effect, tends to be given numerous explanations (progress in schooling, television, nutrition, etc.). One way of studying this effect consists of assessing in which subtests the change in IQ takes place. Using the comparison among 120,000 French children on an intelligence test in ...

It is important to understand potential sources of group differences in the heritability of intelligence test scores. On the basis of a basic item response model we argue that heritabilities which are based on dichotomous item scores normally do not generalize from one sample to the next. If groups differ in mean ability, the functioning of items at different ability levels may result in group ...