This study can have huge practical consequences for everyday life:

In two surveys of nearly 20,000 high schoolers, students who reported using at least one self-control strategy — such as turning off their phone — tended to spend more time practicing for the SAT and had higher SAT scores than students who relied purely on willpower.

While this insight seems relevant, note that even from this short description, you can notice two of the limitations: correlation and self-reporting. But let’s have a further look. Less clear from this short description is one of the stronger elements: the authors also did their own pre-registered replication!

From the press release:

In two surveys of nearly 20,000 high schoolers, students who reported using at least one self-control strategy — such as turning off their phone — tended to spend more time practicing for the SAT and had higher SAT scores than students who relied purely on willpower. Chayce Baldwin of the University of Michigan, Ann Arbor, Angela Duckworth of the University of Pennsylvania, Philadelphia, and co-authors present these findings in the open-access journal PLOS ONE on September 28, 2022.

In working towards a goal, a person might employ self-control strategies that help them align their actions with their goal and avoid appealing alternatives, such as tracking their progress. Alternately, they might employ pure willpower to avoid temptations and force themselves to work. Prior research suggests strategic self-control may be more effective than willpower, but few studies have compared these approaches in real-world settings.

To shed new light, Baldwin and colleagues partnered with the College Board to conduct two survey studies of 19,822 U.S. high-school students. The surveys included questions about how the students motivated themselves while studying for the SAT exam, which is used by colleges to make admission decisions. For instance, students indicated if they had disabled their cellphone, set up a distraction-free place to study or created a study schedule — or if they “just willed themselves” to study.

Statistical analysis of the results showed that the use of self-control strategies was associated with more time spent practicing for the SAT exam and higher SAT scores, even after accounting for differences in socioeconomics and prior achievements among the students.

The more self-control strategies students reported using, the higher their SAT scores tended to be. However, as more strategies were used, the additional benefit of each one diminished, suggesting that students may only need to employ a limited number of self-control strategies to enjoy their apparent benefits.

On the basis of these results, the researchers suggest that helping students use self-control strategies could be a cost-effective way to boost their SAT scores, especially given the high expense of formal SAT coaching. They also call for further observational and experimental research to help confirm and build on these findings.

Abstract of the study:

Self-control is often thought to be synonymous with willpower, defined as the direct modulation of impulses in order to do what is best in the long-run. However, research has also identified more strategic approaches to self-control that require less effort than willpower. To date, field research is lacking that compares the efficacy of willpower to strategic self-control for consequential and objectively measured real-world outcomes. In collaboration with the College Board, we surveyed two national samples of high school students about how they motivated themselves to study for the SAT college admission exam. In Study 1 (N = 5,563), compared to willpower, strategic self-control predicted more hours of SAT practice and higher SAT scores, even when controlling for prior PSAT scores. Additionally, the more self-control strategies students deployed, the higher their SAT scores. Consistent with dose-response curves in other domains, there were positive albeit diminishing marginal returns to additional strategies. Mediation analyses suggest that the benefits of self-control strategies to SAT scores was fully explained by increased practice time. These results were confirmed in Study 2, a preregistered replication with N = 14,259 high school students. Compared to willpower, strategic self-control may be especially beneficial in facilitating the pursuit of goals in high-stakes, real-world situations.