Is there an epidemic of narcissism?

The most interesting articles that came to our attention this week

Fadeout and persistence of intervention impacts on social–emotional and cognitive skills in children and adolescents: A meta-analytic review of randomized controlled trials. Emma Hart and colleagues carry out a meta-analysis of randomized controlled trials on the fadeout effect after interventions. Analysing 86 RCTs, they find that the extent of fadeout is similar for interventions to boost cognitive skills and for those to boost social–emotional skills.

Mechanisms of developmental change in genetic and environmental influences on intelligence. Damien Morris and colleagues re-examine the Wilson effect, the rising heritability of intelligence with age. Analysing longitudinal data for 10,535 twin pairs, they find that heritability rises from 24% at age 2 to 50% at age 16, while shared environmental influence declines from 65% to 10%. Non-shared environmental influence also rises.

Contribution of genes (A), shared environment (C) and non-shared environment (E) at different ages.