Developmental Stage

Publication Type

This article reports findings from the largest-ever randomized controlled trial of a growth mindset program in the United States in K-12 settings. The study combined a test for cause-and-effect (a randomized experiment) with a sample that enables claims about an entire population (a nationally representative probability sample). The study found that a short (less than one hour), online growth mindset intervention—which teaches that intellectual abilities can be developed—improved grades among lower-achieving students and increased enrollment in advanced mathematics courses among both higher- and lower-achieving students in a nationally representative sample of regular public high schools in the United States. Notably, the study identified school contexts that moderated the effects of the growth mindset intervention: the intervention had a stronger effect on grades when peer norms aligned with the messages of the intervention. In addition to its rigorous design, the study also featured independent data collection and processing, pre-registration of analyses, and corroboration of results by a blinded Bayesian analysis.

What can be done to reduce unhealthy eating among adolescents? The research team hypothesized that aligning healthy eating with important and widely shared adolescent values would produce the needed motivation. A double-blind, randomized, placebo-controlled experiment with eighth graders evaluated the impact of a treatment that framed healthy eating as consistent with the adolescent values of autonomy from adult control and the pursuit of social justice. Healthy eating was suggested as a way to take a stand against manipulative and unfair practices of the food industry, such as engineering junk food to make it addictive and marketing it to young children. Compared with traditional health education materials or to a non–food-related control, this treatment led eighth graders to see healthy eating as more autonomy-assertive and social justice oriented behavior and to forgo sugary snacks and drinks in favor of healthier options a day later in an unrelated context. Public health interventions for adolescents may be more effective when they harness the motivational power of that group’s existing strongly held values.

There are many promising psychological interventions on the horizon, but there is no clear methodology for preparing them to be scaled up. Drawing on design thinking, the present research formalizes a methodology for redesigning and tailoring initial interventions. The researchers test the methodology using the case of fixed versus growth mindsets during the transition to high school. The current research provides a model for how to improve and scale interventions that begin to address pressing educational problems. It also provides insight into how to teach a growth mindset more effectively.