Recent evidence from economics and psychology points to the importance of traits other than general intelligence for success in school and in life. Educators are increasingly interested in these so-called “non-cognitive” traits because they hope to influence them in support of academic success as well as long-term life outcomes. For example, many “No Excuses” charter schools have implemented rigorous Positive Behavioral Interventions and Supports (PBIS) systems aimed at molding student behavior in school and beyond in pro-social and pro-academic directions. Yet there are no widely accepted standards for the measurement of non-cognitive traits, little agreement on which non-cognitive traits are most important, and limited evidence on their relationship with conventional measures of academic achievement such as test scores.

We used existing survey instruments to gather information on a broad set of non-cognitive traits from a sample of more than 1,300 8^th-grade students across a wide range of public schools in one city and linked this information to administrative data on students’ demographics and test score performance. The traits we measured included Conscientiousness, Self-control, Grit, and Implicit Theory of Intelligence. The schools attended by students in our sample included open-enrollment district schools, exam schools, and lottery-admission charter schools. 

Our results highlight both the potential value of these measures in explaining the proximate outcome of academic success and a hitherto less discussed paradox inherent to many of these measures. The promise is illustrated by the fact that several of the non-cognitive traits are strongly correlated with gains on standardized tests. The paradox is illustrated by the fact that differences in the mean levels of non-cognitive traits across schools are often in the opposite direction of what would be expected based on these overall correlations. For example, students who attend a set of high-performing “No Excuses” charter schools that have been shown to increase student test scores score significantly worse, on average, on Grit, Conscientiousness and Self-Control than students attending district schools. Exploiting charter school admissions lotteries, we replicate the findings of previous research indicating large positive impacts of charter school attendance on math achievement but find negative impacts on these non-cognitive traits.

Two competing hypotheses could explain this paradox.  One is that the measures are accurate and that contrary to their goals, the charter schools, despite their success in raising test scores, reduce students’ non-cognitive abilities in crucial dimensions such as self-control and conscientiousness.  An alternative hypothesis is that these measures, all self-reported by students, are misleading because they are prone to reference bias – the tendency for individuals’ survey responses to be influenced by the context in which the survey is administered.  We find suggestive evidence supporting this alternative hypothesis, highlighting the importance of improved measurement of non-cognitive traits in order to capitalize on their promise as a tool for informing education practice and policy.