Do young chimpanzees have extraordinary working memory?

Do chimpanzees have better spatial working memory than humans? In a previous report, a juvenile chimpanzee outperformed 3 university students on memory for briefly displayed digits in a spatial array (Inoue & Matsuzawa, 2007). The authors described these abilities as extraordinary and likened the chimpanzee's performance to eidetic memory. However, the chimpanzee received extensive practice on a non-time-pressured version of the task; the human subjects received none. Here we report that, after adequate practice, 2 university students substantially outperformed the chimpanzee. There is no evidence for a superior or qualitatively different spatial memory system in chimpanzees.