This is the secret behind long-term academic success and growth

What one factor is responsible for getting good grades? Of course, there's hard work, and having an engaging and qualified teacher. A well-designed curriculum is also important. But there's another approach that can make a difference, finds a large new National Study of Learning Mindsets. Instilling a growth mindset can make a quick and lasting difference, discovered the scientists.

The national study looked at 12,000 ninth graders from 65 public high schools around the United States. The researchers saw that a helpful intervention can be made to encourage a growth mindset, the belief that intellectual abilities are not fixed solely by genetics but can be developed. You can essentially become smart. Such a mindset can lead to success not just in high school, which 20% of American students don't finish on time, but college and in all aspects of life.

Finishing high school on time is important because not doing so can lead to a host of related issues, like an increased risk of poverty, bad health and early death.

David Yeager, the lead author of the study and an associate professor of psychology at The University of Texas at Austin, said that their research "cemented a striking finding" from previous studies which showed that a brief intervention can affect the grades of teens months later, setting them up for greater achievements.

Interestingly, the study also demonstrated that "higher-achieving students don't get higher grades after the program, but they are more likely to take harder classes that set them up for long-term success," explained Yeager.

The researchers conducted two 25-minute online sessions at the beginning of high school and found that a whole spectrum fo students, from lower to higher-achieving could benefit from the program. The lower-achieving students improved their grades by 0.1 grade points in core subjects like math, English, social studies and science. The program also decreased the amount of students with a D or F average in the courses by 5%.

The intervention also succeeded in growing the number of 10th-grade students who took Algebra II or higher by 3% among both the students who were doing poorly and the high achievers.

Yeager noted that these effects are "substantial when compared to the most successful large-scale, lengthy and rigorously evaluated interventions with adolescents in the educational research literature."

He also pointed out that while the program works and has a low cost to implement, the growth mindset is not "a magic bullet". Its effectiveness depends on the particular circumstances of each school.

Medium- and low-performing schools that applied the growth mindset intervention, steering students to take on more challenging courses, saw low achievers improve their grades by 0.15 grade points in core subjects while performance in STEM courses went up 0.17 points.