It’s an often mentioned chapter in our second Urban Myths book: growth mindset. Many people are surprised to read that the impact of these interventions is often very limited, to say the least. A new study by Yeager and many others, amongst who Carol Dweck, have now studied a possible explanation why mindset interventions sometimes work and sometimes not, and it’s all about the teachers:

The growth mindset is the belief that intellectual abilities can be developed and are not fixed. Growth mindsets have received a great deal of attention in schools and among researchers, in part because of the potential for short, highly scalable interventions delivered over the Internet to benefit struggling students. In this article, we show that the positive effect of a short growth-mindset intervention on ninth-grade students’ math grades was concentrated among students whose teachers themselves had growth mindsets. Interestingly, we discovered that students who reported more of a fixed mindset at baseline benefited more from the intervention. This work shows that students at the intersection of vulnerability (a prior fixed mindset) and opportunity (a growth-mindset environment) are the most likely to benefit from growth-mindset interventions.

Everything is related to the mindset-plus-supportive-context hypothesis, but what is this?

According to the mindset-plus-supportive-context hypothesis, teachers with a growth mindset may convey how, in their class, mistakes are learning opportunities, not signs of low ability, and back up this view with assignments and evaluations that reward continual improvement (Canning et al., 2019; Muenks et al., 2020). This could encourage a student to continue acting on their growth mindsets. By contrast, teachers with more of a fixed mindset may implement practices that make a budding growth mindset inapplicable and locally invalid. For instance, they may convey that only some students have the talent to get an A or say that not everyone is a “math person” (Rattan et al., 2012; also see Muenks et al., 2020). These messages could make students think that their intelligence would be evaluated negatively if they had to work hard to understand the material or if they asked a question that revealed their confusion, discouraging students from acting out key growth-mindset behaviors. According to this hypothesis, the intervention is like planting a “seed,” but one that will not take root and flourish unless the “soil” is fertile (a classroom with growth-mindset affordances; see Walton & Yeager, 2020).

But what were the results?

The effect for students in classrooms with growth-mindset teachers was 0.11 grade points and was significant (p < .001), and there was no significant effect in classrooms of teachers who reported more of a fixed mindset (compare Columns 2 and 3). Notably, our primary analyses did not exclude students whose grades could not have been lifted any further. If we limit our sample to the three fourths of students who were not already making straight As across all of their core classes before the study and who therefore had room to improve their grades, the estimated effect among students in classrooms with growth-mindset teachers becomes slightly larger, 0.14 grade points.

This is not a huge effect, but at the same time, it doesn’t cost that much. Still, one should conside that it will end probably costing more to train or change the mindsets of teachers to achieve this. Being not sure if this is achievable. And yes, they should therefor do this experiment too:

If a future experimental intervention targeted both students and teachers, what kinds of moderation patterns might be expected? There, we actually might see the largest effects for teachers who formerly reported having a fixed mindset. That is, the benefits of both planting a seed and fertilizing the soil should be greatest where soil was formerly inhospitable and smaller where the soil was already adequate.

This is the abstract:

A growth-mindset intervention teaches the belief that intellectual abilities can be developed. Where does the intervention work best? Prior research examined school-level moderators using data from the National Study of Learning Mindsets (NSLM), which delivered a short growth-mindset intervention during the first year of high school. In the present research, we used data from the NSLM to examine moderation by teachers’ mindsets and answer a new question: Can students independently implement their growth mindsets in virtually any classroom culture, or must students’ growth mindsets be supported by their teacher’s own growth mindsets (i.e., the mindset-plus-supportive-context hypothesis)? The present analysis (9,167 student records matched with 223 math teachers) supported the latter hypothesis. This result stood up to potentially confounding teacher factors and to a conservative Bayesian analysis. Thus, sustaining growth-mindset effects may require contextual supports that allow the proffered beliefs to take root and flourish.