Day 1 of the Nijmegen Lectures covered lots of interesting work by Russell and his colleagues, in particular Dr. Alex Taylor, on corvids - they've shown a whole range of incredible things that the New Caledonian crow can do. But first, Russell gave an overview of one of the major current debates in animal cognition: Do animals have human cognition, or a significantly reduced version of it?
 |
| Source: gardenofeaden.blogspot.com |
The romantic view is that humans are fundamentally similar to species. For every characteristic that was once claimed to be uniquely human, people have claimed they have found animal counterparts. Take for example tool use. While first denounced uniquely human by Louis Leakey (who coined the phrase 'Man the Tool Maker'), Jane Goodall quickly debunked this by showing that chimpanzees use tools. (Interestingly, Louis Leakey responded to this by stating: "Now we must redefine tool, redefine Man, or accept chimpanzees as humans.") But people have argued similar cases for theory of mind, causative cognition, even recursion.
The killjoys on the other hand claim that simpler mechanisms than full-blown human cognition can explain animal behaviour observed in experiments (typically associative learning). As earlier as 1894, it was argued that: "In no case may we interpret an action as the outcome of the exercise of one which stands lower in the psychological scale." (Morgan, 1894, 53). This statement is referred to as 'Morgan's Canon'.
Through discussing a series of very interesting experiments (see references), Russell showed that he had been on both sides of the debate. However, he also showed that both camps had problems they need to deal with: The romantic view for example is evolutionary implausible - evolution does not proceed in miraculous leaps. Furthermore, claims of human-like "super cognitive" abilities such as 'insight' don't identify cognitive mechanisms (that can be tested). The 'killjoy' view on the other hand is not evolutionary plausible either - assuming that many animals have identical cognitive abilities is not plausible (for one, they are physically different, too). The biggest failure of this view is that it leaves differences between species unexplained.
Rather, Russell suggests to follow the following research program, 'without miracles' but with incremental steps: For example, New Caledonian crows may be where they are now through small (morphological) tweaks (such as the change of the beak of the New Caledonian crow, and its more binocular view), small changes in the brain (Medina et al., 2013), and tweaks in the developmental course (Kenward et al., 2011). This suggests that the animal cognition question raised above is just the wrong question.
In future research, then, we should move from so-called 'gee whizz' experiments to signature testing. That is, develop a theory-driven battery of tests, that preferably can be administered to a range of different species. While administring these tests, both the success and also the failures should be monitored. Finally, more comparative (phylogenetic) research is required, including genomics, neuroscience and developmental research. In sum, abandon the dichonomous debate on romantics vs killjoys, but take a more practical stance where verifiable hypotheses are brought forward and tested. Rather than comparing humans to other species, we should do signature testing and develop a good understanding of the biology of related species to the one we are testing, to discover the incremental, intermediate steps which may have taken place.
Selected references
- Holzhaider, J. C., Hunt, G. R., Campbell, V. M., & Gray, R. D. (2008). Do wild New Caledonian crows (Corvus moneduloides) attend to the functional properties of their tools?. Animal Cognition, 11(2), 243-254.
- Hunt, G.R., Gray R.D. (2006). Tool manufacture by New Caledonian crows: chipping away at
human uniqueness. Acta Zoologica Sinica 52 (Suppl.): 622-625.
- Kenward, B., Schloegl, C., Rutz, C., Weir, A. A., Bugnyar, T., & Kacelnik, A. (2011). On the evolutionary and ontogenetic origins of tool‐oriented behaviour in New Caledonian crows (Corvus moneduloides). Biological Journal of the Linnean Society, 102(4), 870-877.
- Medina, F. S., Hunt, G. R., Gray, R. D., Wild, J. M., & Kubke, M. F. (2013). Perineuronal satellite neuroglia in the telencephalon of New Caledonian crows and other Passeriformes: evidence of satellite glial cells in the central nervous system of healthy birds?. PeerJ, 1, e110.
- Taylor, A. H., Knaebe, B., & Gray, R. D. (2012). An end to insight? New Caledonian crows can spontaneously solve problems without planning their actions. Proceedings of the Royal Society B: Biological Sciences, 279(1749), 4977-4981.
- Taylor, A.H., Miller, R. and Gray, R.D. (2012). New Caledonian crows reason about hidden causal agents. PNAS published ahead of print September 17, 2012, doi:10.1073/pnas.1208724109
Further reading
- Heyes, C. (2012). Simple minds: a qualified defence of associative learning. Philosophical Transactions of the Royal Society B: Biological Sciences, 367(1603), 2695-2703.
