Genetic influence on family environment: The role of personality.

The relation between genetic influence on personality (extraversion and neuroticism) and genetic influence on family environment measures was examined. More than 400 pairs of twins were assessed at the average age of 59 yrs. Trivariate quantitative genetic model-fitting analyses indicated that genetic influence on a Relationship dimension and a Personal Growth dimension of the environmental measure was shared with genetic effects on personality. However, the majority of genetic variance was unique to these measures. The genetic influence on a System Maintenance dimension was largely independent of genetic variance on personality. Taken together, these results suggest that more remains to be explained in the puzzle of genetic influence on environmental measures. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Structural invariance of cognitive abilities across the adult life span: A cross-sectional study.

This study examined the hypothesis that psychometric tests retain equivalent factor structures across samples widely differing in age. We estimated a best-fitting measurement model for 17 psychometric tests covering the 5 primary abilities of Inductive Reasoning, Spatial Orientation, Verbal Ability, Numerical Ability, and Perceptual Speed, using a sample of 1,621 participants (ages 22 to 95) from the 5th wave of the Seattle Longitudinal Study. We disaggregated the participants into 9 subsets (M ages?=?29, 39, 46, 53, 60, 67, 74, 81, and 90) and tesed the fit of the accepted model for each subset. We confirmed configural invariance for all subsets, but could not establish either complete or incomplete metric invariance for any set. These results confirm the stability of factor patterns across age but indicate serious limitations for valid cross-age comparisons of individual markers of psychometric abilities in age-comparative studies. (PsycINFO Database Record (c) 2010 APA, all rights reserved)