Genetic analysis of cognitive failures (CFQ); A study of Dutch adolescent twins and their parents

A substantial part of the inter-individual variation in everyday cognitive failures in memory, perception and motor control can be attributed to genetic factors. Cognitive failures were assessed with the Cognitive Failures Questionnaire (Broadbent, Cooper, FitzGerald and Parkes, 1982) in a large sample of Dutch adolescent twin pairs and their biological parents. The heritability for CFQ scores was around 50 per cent. There was no association between CFQ scores and age or educational level. Both in the parental generation (aged 46 years on average) and in the o€spring generation (aged 17.7 years on average) women had somewhat higher mean CFQ scores than men. There were no sex di€erences in heritabilities. The part of the variance that could not be attributed to genetic factors was best explained by environmental in¯uences unique to the individual. There was no evidence for the in¯uence of shared environment on CFQ scores. CFQ scores of husband and wife were correlated (r ˆ 0.22) and this association was modeled as phenotypic assortment. The correlations between parents and o€spring were somewhat lower than the correlations between dizygotic twins. Under a model with equal heritabilities in parents and o€spring, there was some evidence that the genetic factors that in¯uence cognitive failures in the two generations are partly di€erent. # 1998 John Wiley & Sons, Ltd

Diminished impact of cytomegalovirus infection on graft vasculopathy development in the antiviral prophylaxis era – a retrospective study

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Taxonomy and structure of the Romanian personality lexicon

We identified 1746 personality-relevant trait-adjectives in a Romanian dictionary, of which 412 were classified as descriptors of dispositions by 10 judges. Self-ratings were collected from 515 participants on those 412 adjectives, and the ratings were factored using principal components analysis. Solutions with different numbers of factors were analysed. The two- and three-factor solutions, respectively, confirmed the Big Two and Big Three of personality traits. A five-factor solution reflected the Big Five model with a fifth factor emphasising Rebelliousness versus Conventionality. The five-factor solution was related to the International Personality Item Pool-Big Five scales, and the highest correlations were indeed between the corresponding factors and scales. A six-factor solution was indicative of the six-factor model as expressed in the HEXACO model, yet with a weak Honesty-Humility factor. Additional analysis with self-ratings from 218 participants on marker-scales for the six-factor solution and on the six scales of the HEXACO did not produce a clear one-to-one correspondence between the two sets of scales, confirming indeed that the six-factor model was only partially found

Prediction of Psilocybin Response in Healthy Volunteers

Responses to hallucinogenic drugs, such as psilocybin, are believed to be critically dependent on the user's personality, current mood state, drug pre-experiences, expectancies, and social and environmental variables. However, little is known about the order of importance of these variables and their effect sizes in comparison to drug dose. Hence, this study investigated the effects of 24 predictor variables, including age, sex, education, personality traits, drug pre-experience, mental state before drug intake, experimental setting, and drug dose on the acute response to psilocybin. The analysis was based on the pooled data of 23 controlled experimental studies involving 409 psilocybin administrations to 261 healthy volunteers. Multiple linear mixed effects models were fitted for each of 15 response variables. Although drug dose was clearly the most important predictor for all measured response variables, several non-pharmacological variables significantly contributed to the effects of psilocybin. Specifically, having a high score in the personality trait of Absorption, being in an emotionally excitable and active state immediately before drug intake, and having experienced few psychological problems in past weeks were most strongly associated with pleasant and mystical-type experiences, whereas high Emotional Excitability, low age, and an experimental setting involving positron emission tomography most strongly predicted unpleasant and/or anxious reactions to psilocybin. The results confirm that non-pharmacological variables play an important role in the effects of psilocybin

Personality profiles of cultures: aggregate personality traits

Personality profiles of cultures can be operationalized as the mean trait levels of culture members. College students from 51 cultures rated an individual from their country whom they knew well (N = 12, 156). Aggregate scores on Revised NEO Personality Inventory scales generalized across age and gender groups, approximated the individual-level Five-Factor Model, and correlated with aggregate self-report personality scores and other culture-level variables. Results were not attributable to national differences in economic development or to acquiescence. Geographical differences in scale variances and mean levels were replicated, with Europeans and Americans generally scoring higher in Extraversion than Asians and Africans. Findings support the rough scalar equivalence of NEO-PI-R factors and facets across cultures, and suggest that aggregate personality profiles provide insight into cultural differences