New study on chimpanzee working memory
https://royalsocietypublishing.org/doi/pdf/10.1098/rspb.2019.0715
“Our findings suggest that chimpanzees perform similar to seven-year-old children in an intuitive working memory task that does not rely on extensive training,” says Christoph Voelter
https://www.sciencedaily.com/releases/2019/07/190723211656.htm