I just learned of a new essay by Drs. David Leavens, Kim Bard, and William Hopkins published in the journal Animal Cognition that deserves wide and critical readership. This significant and comprehensive research paper is titled "The mismeasure of ape social cognition," and it contains a wealth of important information that clearly shows that we need to be extremely careful about claiming that humans are all that unique -- read "smarter" -- when comparing our skills in social cognition with those of nonhuman great apes. 

I fully realize that the original essay will take some time to read and to digest even for professional researchers, but it's well worth the effort. Here are a few snippets from this piece that nicely summarize the detailed analyses Drs. Leavens, Bard, and Hopkins conducted. Below I'll provide some statements from an easy to read general summary. In the original essay we read:

On both methodological and logical grounds, the mental causality model of psychological processes has failed to produce any unambiguous ape–human differences in social cognition. Despite numerous claims to the contrary, no current scientific methodology has isolated evolutionary history as the causal factor in alleged ape–human differences in social cognition. Moreover, every such claim of a “species difference” has been refuted by superior methodological approaches, involving within-species explorations of specific competencies (see notes to Table 1). Thus, where differences have been reported between ape and human groups, the relevant factors accounting for these differences (environmental, genetic) remain unknown. Thus, to claim a “species difference” in social cognition between apes and humans, at our present state of knowledge, is to promulgate the same kinds of prejudices that hereditarians evinced in the early history of biometric approaches to the study of intelligence—all group differences were taken to be evidence for innate, primary differences in abilities between different groups of humans, and environmental influences on mental development were routinely ignored (Gould 1981). Tables 1 and 2 document the same sort of wishful thinking (systematic bias) in the face of the numerous confounds listed there.

On logical grounds, the existence of hypothetical, causal mental states cannot be confirmed, with present technology. Hence, there is no evidence that the communicative signaling of humans, great apes or other animals, is predicated on substantially different cognitive bases.

Drs. Leavens, Bard, and Hopkins discuss problems centering on confounded research designs, problems with how different species were compared, problems in cross-fostering studies in which members of different species are reared or housed together -- in this case apes being raised by humans, concerns about how animals are trained, and the unfalsifiability (untestability) of models of mental causation. All in all, the researchers write, "None of the studies in Table 1 constitutes a scientifically legitimate claim for uniquely human communicative motivations or cognitive processes."

Researcher Kim Bard: "In examining the literature, we found a chasm between evidence and belief."

Because of the importance of the topic at hand, I recommend an easy to read summary of "The mismeasure of ape social cognition" called "Apes' abilities misunderstood by decades of poor science." This essay begins, "A new analysis argues that what we think we know about apes' social intelligence is based on wishful thinking and flawed science." Dr. Leavens is quoted as saying, 

 "The fault underlying decades of research and our understanding of apes' abilities is due to such a strongly-held belief in our own superiority, that scientists have come to believe that human babies are more socially capable than ape adults. As humans, we see ourselves as top of the evolutionary tree. This had led to a systematic exaltation of the reasoning abilities of human infants, on the one hand, and biased research designs that discriminate against apes, on the other hand.

"Even when apes clearly outperform young human children, researchers tend to interpret the apes' superior performance to be a consequence of inferior cognitive abilities.

"There is not one scientifically sound report of an essential species difference between apes and humans in their abilities to use and understand clues from gestures, for example. Not one.

"This is not to say such a difference won't be found in future, but much of the existing scientific research is deeply flawed."

I'm quoting Dr. Leavens in full because it is essential to be precise about what he said. The details really count.  

Concerning sampling we read, "almost all studies comparing humans with apes have compared humans from a small group - Western, educated, industrialised, rich and democratic - with apes who have been orphaned and/or raised in sterile institutions. In 2014, Professor Bard and Dr Leavens proposed, in the Annual Review of Anthropology, that more than a single group of humans should be compared to more than a single group of apes to determine the influence of environment on communicative outcomes, for example." By expanding the variety of humans and nonhuman great apes who are studied, more reliable comparative assessments of their cognitive capacities can be made. 

"Direct comparisons of humans with apes suffer from pervasive lapses in argumentation."

​This statement is a fair and general summary of what Drs. Leavens, Bard, and Hopkins conclude in their detailed comparative analyses. I've always been leery of scaling intelligence across species, including, for example, claims that chimpanzees behave like young children in certain types of experiments. I've also been cautious and have argued against claims such as dogs are smarter than cats or dogs are smarter than mice or crows are smarter than sparrows. Cross-species comparisons are fraught with error because individuals have to do what they need to do to be card-carrying members of their species. So, dogs can do things cats and mice can't do and mice can do things neither dogs nor cats can do. However, it would be misleading to claim that members of one species are smarter than individuals of the other species. For more on the topic of cross-species comparisons of intelligence, please see "Are Pigs as Smart as Dogs and Does It Really Matter?"

So, just how smart are we? In one of his books renowned primatologist Dr. Frans de Waal asks, Are We Smart Enough to Know How Smart Animals Are? According to de Waal, "So, yes, we are smart enough to appreciate other species, but it has required the steady hammering of our thick skull with hundreds of facts that were initially poo-pooed by science." (p. 5) He also notes that he "emphasizes evolutionary continuity at the expense of traditional dualisms" as do numerous researchers and I. Another point de Waal stresses is that we are animals and that he views "human cognition as a variety of animal cognition." (p. 5) Surely from an evolutionary point of view, this is a good move. 

In an essay I published in 2011 called "Animal Minds and the Foible of Human Exceptionalism" I concluded, "The time has come to debunk the myth of human exceptionalism once and for all (for further discussion see, for example, Lori Gruen's Ethics and Animals). It's a hollow, shallow, and self-serving perspective on who we are. Of course we are exceptional in various arenas as are other animals. Perhaps we should replace the notion of human exceptionalism with species exceptionalism, a move that will force us to appreciate other animals for who they are, not who or what we want them to be." I also have argued that we need to think seriously about individual exceptionalism, because there are significant variations in cognitive capacities among individuals of the same species that sometimes are larger than variations between individuals of different species. 

All in all, I hope that "The mismeasure of ape social cognition" will receive a broad audience. It'll take some time to get through it, however, the details provided are exemplary as are the methods of analysis. I'm sure that some people will debate the authors' conclusions, but this is just fine and will get much-needed discussions on the table. However, one thing is certain, and that is we surely have to be very careful when making cross-species comparisons.

Please stay tuned for more on the "hot" topic of cross-species comparisons of intelligence. I'm sure there will be a lot of exciting forthcoming research projects and wide ranging discussions and debates as the issues are studied and published. It's also clear that data that have been collected in past studies need to be revisited, as Drs. Leavens, Bard, and Hopkins have done. 

The bottom line is clear: Placing humans on top of some mythical pyramid of cognitive capacities and offering speciesistic claims that humans are all that special, unique, better, and/or "smarter" than other animals need to be toned down and preferably, placed on hold. Time after time these misleading and demeaning pyramids have crumbled under careful scrutiny. 

Marc Bekoff’s latest books are Jasper’s Story: Saving Moon Bears (with Jill Robinson); Ignoring Nature No More: The Case for Compassionate Conservation; Why Dogs Hump and Bees Get Depressed: The Fascinating Science of Animal Intelligence, Emotions, Friendship, and Conservation; Rewilding Our Hearts: Building Pathways of Compassion and Coexistence; The Jane Effect: Celebrating Jane Goodall (edited with Dale Peterson); and The Animals’ Agenda: Freedom, Compassion, and Coexistence in the Human Age (with Jessica Pierce). Canine Confidential: Why Dogs Do What They Do will be published in early 2018. Learn more at marcbekoff.com.

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