a fixed mindset is characterized by an “entity” view of intelligence as a set quantity that cannot be changed.
In a recent study, researchers used a simple 55mn intervention to promote a growth mindset among 9th grade students in two American public schools, and observed that their incremental views increased by almost 10% and stabilized at this new level in a later follow-ups, while their performance-goals orientation decreased.
"Performance" goals are extrinsically motivated, and opposed to "mastery" goals, which focus on the development of knowledge and acquisition of skills.
The intervention consisted in a simple lesson on neuroplasticity (e.g., the ability of the brain to grow, like a muscle, through exercise), followed by a comprehension test and a self-persuasion task during which the students were asked to write a letter to a middle school student about what they had learned.
Results were replicated the following year with new cohorts of students from the same two high schools.
Source: DeBacker et alia (2018)