„Adolescent achievement test scores only explain at most 17 % of the variability in later-life earnings. […] Achievement tests do not adequately capture non-cognitive skills such as perseverance (‚grit‘), conscientiousness, self-control, trust, attentiveness, self-esteem and self-efficacy, resilience to adversity, openness to experience, empathy, humility, tolerance of diverse opinions and the ability to engage productively in society, which are valued in the labour market, in school, and in society at large.“
Dr. Tim Kautz u. a., „Fostering and Measuring Skills: Improving Cognitive and Non-Cognitive Skills to Promote Lifetime Success“ (2014), S. 9