“On the Working Memory of Humans and Great Apes: Strikingly Similar or Remarkably Different?”, 2021-12-14 (; similar):
Data from natural settings and laboratories imply Pan working memory (WM) is 2 ± 1
WM increases until puberty but puberty occurs at half the age for Pan as for humans
Claims for extraordinary working memory in Pan are not supported by data
WM increase during hominin evolution parallels complexity increase in stone artifacts
Cumulative WM changes in Homo sapiens evolution led to qualitative cognitive changes
In this article we review publications relevant to addressing widely reported claims in both the academic and popular press that chimpanzees working memory (WM) is comparable to, if not exceeding, that of humans. WM is a complex multidimensional construct with strong parallels in humans to prefrontal cortex and cognitive development. These parallels occur in chimpanzees, but to a lesser degree.
We review empirical evidence and conclude that the size of WM in chimpanzees is 2 ± 1 versus Miller’s famous 7 ± 2 in humans. Comparable differences occur in experiments on chimpanzees relating to strategic and attentional WM subsystems. Regardless of the domain, chimpanzee WM performance is comparable to that of humans around the age of 4 or 5.
Next, we review evidence showing parallels among the evolution of WM capacity in hominins ancestral to Homo sapiens, the phylogenetic evolution of hominins leading to Homo sapiens, and evolution in the complexity of stone tool technology over this time period.
[Keywords: working memory, human evolution, cognitive evolution, comparative psychology, chimpanzee, hominin evolution, theory of mind, planning]