These findings have several implications relevant to the psychology of memory and cognition, and are likely to explain differences between higher cognitive abilities of humans and non-humans. The present evidence shows that non-human mammals and birds, regardless of their limitations, are capable of performing memory strategies, although there seem to be some differences between their ability and that of humans in terms of flexibility and efficiency. Moreover, the results imply an increasing trend of capacity from our non-human ancestors to modern humans. The findings suggest the limited capacity to be the common attribute of different species of birds and mammals. The present study is devoted to reviewing the literature of memory studies from an evolutionary, comparative perspective, focusing particularly on short term memory capacity. However, in spite of their critical importance, many aspects of their evolution remain underinvestigated. Working memory and its components are among the most determinant factors in human cognition. 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. Regardless of the domain, chimpanzee WM performance is comparable to that of humans around the age of 4 or 5. Comparable differences occur in experiments on chimpanzees relating to strategic and attentional WM subsystems. We review empirical evidence and conclude that the size of WM in chimpanzees is 2 ± 1 versus Miller’s famous 7 ± 2 in humans. These parallels occur in chimpanzees, but to a lesser degree. WM is a complex multidimensional construct with strong parallels in humans to prefrontal cortex and cognitive development.

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.

Eidetic memory vs iconic memory