de Waal and Ferrari on cognition in humans and animals

Humans do many things that most animals can’t. That much no one would dispute. The more interesting and controversial question is just how many things we can do that most animals can’t, and just how many animal species can or can’t do the things we do. That question is at the center of a nice opinion piece in Trends in Cognitive Sciences by Frans de Waal and Pier Francisco Ferrari.

De Waal and Ferrari argue for what they term a bottom-up approach to human and animal cognition. The fundamental idea–which isn’t new, and in fact owes much to decades of de Waal’s own work with primates–is that most of our cognitive abilities, including many that are often characterized as uniquely human, are in fact largely continuous with abilities found in other species. De Waal and Ferrari highlight a number of putatively “special” functions like imitation and empathy that turn out to have relatively frequent primate (and in some cases non-primate) analogs. They push for a bottom-up scientific approach that seeks to characterize the basic mechanisms that complex functionality might have arisen out of, rather than (what they see as) “the overwhelming tendency outside of biology to give human cognition special treatment.”

Although I agree pretty strongly with the thesis of the paper, its scope is also, in some ways, quite limited: De Waal and Ferrari clearly believe that many complex functions depend on homologous mechanisms in both humans and non-human primates, but they don’t actually say very much about what these mechanisms might be, save for some brief allusions to relatively broad neural circuits (e.g., the oft-criticized mirror neuron system, which Ferrari played a central role in identifying and characterizing). To some extent that’s understandable given the brevity of TICS articles, but given how much de Waal has written about primate cognition, it would have been nice to see a more detailed example of the types of cognitive representations de Waal thinks underlie, say, the homologous abilities of humans and capuchin monkeys empathize with conspecifics.

Also, despite its categorization as an “Opinion” piece (these are supposed to stir up debate), I don’t think many people (at least, the kind of people who read TICS articles) are going to take issue with the basic continuity hypothesis advanced by de Waal and Ferrari. I suspect many more people would agree than disagree with the notion that most complex cognitive abilities displayed by humans share a closely intertwined evolutionary history with seemingly less sophisticated capacities displayed by primates and other mammalian species. So in that sense, de Waal and Ferrari might be accused of constructing something of a straw man. But it’s important to recognize that de Waal’s own work is a very large part of the reason why the continuity hypothesis is so widely accepted these days. So in that sense, even if you already agree with its premise, the TICS paper is worth reading simply as an elegant summary of a long-standing and important line of research.

3 thoughts on “de Waal and Ferrari on cognition in humans and animals”

  1. I think Chomsky said something like “We just don’t know what happens when you put 100 billion neurons together”. His point being that human uniqueness might not be something we “evolved to have”, but some kind of emergent property of having a brain of a certain complexity. We were apes evolving to have slightly bigger brains, for whatever reason, until something mysterious kicked in and we became human.

    In which case our humanness is fundamentally unique, and whatever we may still have in common with animals, our humanness doesn’t depend on it.

    I don’t think he was saying that this did happen, rather that we have no way of knowing whether it did or not, because fundamentally the brain is a mystery, we don’t know how it produces intelligence, or conciousness. So something uniquely mysterious might have happened during evolution for all we know.

  2. I think it’s true in a trivial sense that humans are unique, and it may well be true that human intelligence is an emergent and fundamentally mysterious property. But I think that’s really a “god of the gaps” type of explanation that we adopt as a last resort, not a viable first-pass explanation. There are all sorts of interesting cases where people attribute some ability or phenomenon to humans without realizing that there are direct analogs in other species with (presumably) much simpler cognitive architectures.

    One of my favorite examples of this sort is Sam Gosling’s work showing that you can reliably identify very similar dimensions of personality in both humans and many other mammalian species. The reason that’s really important is that it suggests that individual differences in many dimensions of personality likely emerge from very basic mechanisms that have been in the mammalian line for a long time, rather than requiring appeal to high-level cognitive abilities that only humans have. For instance, if you think some people are Extraverted because they hold certain beliefs about how other people are likely to respond to them in social situations, you’re going to have a hard time explanation how there could be extraverted and introverted dogs. Presumably dogs don’t have very clear beliefs about what other people are like! So that’s the kind of thing I’m talking about (and that de Waal’s work is a prime example of).

    Obviously, you probably can’t explain everything about human behavior by appeal to simpler animal models, but I do think we should make a strong effort in that direction before falling back on the Chomsky position (which I understand to be that we’re just “cognitively closed” to some phenomena, in much the same way that a rat can’t do calculus).

  3. Tal: I basically agree but I’m enjoying playing Devil’s (or Chomsky’s) Advocate, so here goes:

    Sure, there are lots of parallels between human and animal brains, and behaviours. But no-one denies this. No-one denies that structurally they are very similar and no-one denies that the same mechanisms regulate the simplest functions like breathing or digestion. Simple emotions like fear and things like sleeping and waking, are probably the same.

    But humans are still fundamentally unique. Take an Apollo rocket vs. a little firework rocket. A naive rocket-ologist might look at them both and say “Well they both burn fuel, and the chemistry of the reaction is pretty similar… hot gas comes out a hole in the back propelling them forward… they’ve both got an aerodynamic shape… they’re pretty much the same!”

    True on one level, but if you’re interested in space exploration, the Apollo rocket can fly you to the moon and back, whereas the firework just can’t. It can’t even fly a grain of sand to the moon, or fly you to the top of a small tree. It’s not a space rocket. A difference in degree becomes a difference in kind.

    Back to the brain, the analogy would be that humans and animals are similar in certain respects, but humans have, in addition, a qualitatively different kind of intelligence which allows them to do much more than animals ever could; the fact that in some areas of our lives we don’t, in fact, bother to do this, doesn’t change the fact that we have the capability.

    Like all mammals we sleep but unlike mammals we can choose to stay awake any given point, if we want to, with the aid of coffee or otherwise. We generally don’t, but we could, so saying “like all mammals, humans sleep” is only half true. It would be better to say that “like all mammals, humans have a physiological drive to sleep, but unlike other mammals they exercise rational choice in deciding when to fulfill it.”

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