In “I Got This,” a chapter on confidence, I review some of the factors responsible for giving people a lucky advantage when developing their abilities:

Teachers told that certain students are poised for an academic breakout give those kids more positive feedback and more chances to try throughout the year; the grades of those “future star” students did spike, even though those students were chosen completely at random. Coaches with greater expectations of certain athletes give them more “I got this” marbles over time by offering more instruction, positive reinforcement, higher-quality feedback, and more chances to practice—all of which ultimately improve performance.

You may have heard of the study that the first sentence refers to: “Pygmalion in the Classroom,” a study published in 1968 by Robert Rosenthal and Lenore Jacobson (PDF available here.) In that study, some students had been deemed “growth spurters” based on their scores on the Harvard Test of lnflected Acquisition. The test didn’t exist, but over the course of the year, their test scores rose compared to students in the control group at a rate that would only occur by chance 2 times out of 100.

The second sentence in that paragraph explains how having higher expectations about someone’s future ability can create an actual boost in their performance in the world of sports: coaches or teachers explain things more thoroughly, offer more praise, do a better job of explaining what they did well or how they could improve, and give them more chances to improve or practice.