Below are corrections to errors of various kinds in our publications.
We apologize for any confusion or consternation these errors might have caused any reader.

If you find any other errors in our work, please contact Zach Hambrick at

  • [7/10/2016] In the July 6, 2016, The Conversation article "There’s more than practice to becoming a world-class expert" (Hambrick & Ullén), there are two errors in the third paragraph; the text should read, "'Peak: Secrets from the New Science of Expertise'" and "Robert Pool." (Corrections in bold.)

  • [2/6/2018] In Chapter 9 (Macnamara et al., 2017) in the Science of Expertise book, the note of Table 9.1 (p. 157) should state that Ericsson (2014a) misquotes Ericsson and Lehmann's (1996) definition of deliberate practice, not Lehmann and Ericsson's (1996) definition. For the definition that Ericsson (2014a) misquotes, see Ericsson and Lehmann (1996, pp. 278-279).
  • [3/23/2018] Corrections to Hambrick, D. Z., Burgoyne, A. P., Macnamara, B. N., & Ullén, F. (2018). Beyond born versus made. Annals of the New York Academy of Sciences, based on corrected analyses for Macnamara, Hambrick, & Oswald (2014), and Macnamara, Moreau, & Hambrick (2016):

      p. 2: "However, deliberate practice explained less than half of the variance in music performance under a range of reliability assumptions—for example, 47% assuming “acceptable” reliability of 0.70 for both measures (Fig. 1C)." (Correction in bold).

      p. 2: "A recent meta-analysis of sports studies found that, overall, deliberate practice explained 20% of the variance in expertise, but explained less than 1% of the variance in studies that compared elite performers to “sub-elite” performers (e.g., international- to national-level athletes)." (Corrections in bold.)

      Figure 1C: Percentages should be 47% (Deliberate Practice) and 53% (Other).