As recounted in Professor Ericsson’s book “Peak” (2016), the student could recall in excess of 80 digits by the end of the summer, far more than what was then believed a typical person could memorize.
At Florida State University, where he went in 1992 and remained until his death, Professor Ericsson would ask students to choose a new skill, like juggling, and to practice it during the semester, to prove that they could do something previously thought unlearnable.
As his research became more widely respected, Professor Ericsson was hired to consult with professional sports teams like the Philadelphia Eagles, Minnesota Twins and England’s Manchester City soccer club, and to speak to organizations like Google and the Central Intelligence Agency — each looking for a performance edge he might offer.
He had his critics. One of them, Zachary Hambrick, a professor of psychology at Michigan State University, co-wrote a paper in 2014 that concluded that deliberate practice was not the sole reason for peak performance in chess players and musicians. Innate characteristics like talent and intelligence, Mr. Hambrick argued, play a far more significant role than Professor Ericsson allowed for.
“There’s a side of me that resonates with his hopeful message,” said Scott Barry Kaufman, a humanistic psychologist who studies creativity and hosts “The Psychology Podcast.” “However, there’s another side of me that has seen the research in a wide range of aspects in the field, that suggests that we can have some pretty severe limits on what we can achieve in life.”
Nevertheless, Mr. Kaufman added, “I don’t think any of this invalidates his contributions. He showed that humans have the capacity to go beyond, from one generation to the next, what had been thought of the limits of human potential.”
In addition to his wife, Professor Ericsson is survived by two children from a previous marriage, Jens and Lina Ericsson; a brother, Lasse Ericsson; a sister, Kerstin Loden; and a grandson.