„Only very early interventions (before age three) improve IQ in a lasting way, consistent with the evidence that early childhood is a critical period for cognitive development. The most successful interventions target pre-schoolers (after age three) and primary school children. They improve later-life outcomes by developing non-cognitive skills.“
Dr. Tim Kautz u. a., „Fostering and Measuring Skills: Improving Cognitive and Non-Cognitive Skills to Promote Lifetime Success“ (2014), S. 34