From Barbara J. King at NPR:
Now, psychologists David A. Leavens of the University of Sussex, Kim A. Bard of the University of Portsmouth, and William D. Hopkins of Georgia State University have framed their new Animal Cognition article, “The mismeasure of ape social cognition,” around Gould’s book. Ape (especially chimpanzee) social intelligence, the authors say, has been routinely mismeasured because apes are tested in comprehensively different circumstances from the children with whom they are compared — and against whose performance theirs is found to be lacking.
Leavens et al. write:
“All direct ape-human comparisons that have reported human superiority in cognitive function have universally failed to match the groups on testing environment, test preparation, sampling protocols, and test procedures.”
Confounding factors in these experiments, in other words, are essentially fatal: They render the conclusions unreliable. The testing procedures are so different between apes and children that it becomes impossible to isolate evolutionary history as the explanatory factor when differences in social cognition are uncovered.More.
The problem, is that no matter how they want to do the tests, children go on to advanced cognition and apes do not. Among the wars on reality that post-modernism sponsors, this is surely one of the most odd.
See also: Chimps can learn to use tools on their own, without being taught
Are apes entering the Stone Age?