Reconsidering the Heritability of Intelligence in Adulthood: Taking Assortative Mating and Cultural Transmission into Account

Heritability estimates of general intelligence in adulthood generally range from 75 to 85%, with all heritability due to additive genetic influences, while genetic dominance and shared environmental factors are absent, or too small to be detected. These estimates are derived from studies based on the classical twin design and are based on the assumption of random mating. Yet, considerable positive assortative mating has been reported for general intelligence. Unmodeled assortative mating may lead to biased estimates of the relative magnitude of genetic and environmental factors. To investigate the effects of assortative mating on the estimates of the variance components of intelligence, we employed an extended twin-family design. Psychometric IQ data were available for adult monozygotic and dizygotic twins, their siblings, the partners of the twins and siblings, and either the parents or the adult offspring of the twins and siblings (N = 1314). Two underlying processes of assortment were considered: phenotypic assortment and social homogamy. The phenotypic assortment model was slightly preferred over the social homogamy model, suggesting that assortment for intelligence is mostly due to a selection of mates on similarity in intelligence. Under the preferred phenotypic assortment model, the variance of intelligence in adulthood was not only due to non-shared environmental (18%) and additive genetic factors (44%) but also to non-additive genetic factors (27%) and phenotypic assortment (11%).This non-additive nature of genetic influences on intelligence needs to be accommodated in future GWAS studies for intelligence

On the role of computers in creativity-support systems

We report here on our experiences with designing computer-based creativity-support systems over several years. In particular, we present the design of three different systems incorporating different mechanisms of creativity. One of them uses an idea proposed by Rodari to stimulate imagination of the children in writing a picture-based story. The second one is aimed to model creativity in legal reasoning, and the third one uses low-level perceptual similarities to stimulate creation of novel conceptual associations in unrelated pictures.We discuss lessons learnt from these approaches, and address their implications for the question of how far creativity can be tamed by algorithmic approaches

Prospective memory performance in older people, adults and youth

The aims of this study were to verify the potential differences in prospective memory (PM) among young people, adults and the elderly; analyze the relationships between variables of comprehension and verbal fluency and PM; and finally, verify the existence of a relationship between self-reported health status and performance on PM. A cross- sectional design was used. The study involved 270 participants divided into three age groups: young people aged 18 to 28 years; adults 45 to 55, and seniors 60 to 80. Their comprehension and verbal fluency skills were assessed as well as their self-perceived health status. Subsequently, an experiment was carried out where participants were presented with paragraphs of three sentences on a computer screen and they had to recognize previously agreed words that would indicate their level of MP. The results established significant differences in prospective memory between adults and older people and between young people and the elderly. But no differences between youth and adults were found..The importance of verbal comprehension and verbal fluency in solving prospective memory experimental tasks was also significant. In addition, a better self-perception of well-being was linked to a higher performance in PMEste trabajo fue posible gracias a la financiación del grupo de investigación HUM634 de la Junta de Andalucía y al contrato OTRI de este grupo con la Diputación provincial de Cádiz. El primer autor fue becario AECID en el Departamento de Psicología de la UCA durante la realización del estu

Is There a Place for Ipsilesional Eye Patching in Neglect Rehabilitation?

Neglect behavior of experimental animals with unilateral posterior cortical lesions improves with the placement of a second lesion in the contralesional superior colliculus or in the intercollicular commissure. Given that the retinotectal fibers are mainly crossed, it has been speculated that ipsilesional eye patching, by depriving the contralesional superior colliculus of its main facilitatory visual input, might achieve similar results, and thus be used as a remediation maneuver in patients with neglect. From six patients with severe persistent neglect, only one showed an unequivocal beneficial effect from ipsilesional eye patching. We discuss the factors which possibly underlie success and failure with this procedure, and the place for it in neglect rehabilitation